Quote from: Mr. Foxen on September 25, 2012, 02:16:59 PM
(http://i17.photobucket.com/albums/b69/Incarante/burnt2_zps465d07f0.jpg)
Quote from: Mr. Foxen on September 25, 2012, 02:24:20 PM
(http://ampstack.files.wordpress.com/2012/04/foiled.jpg)
Hemi,
Great thread! what do you know about the Peavey VTX head. It has a 4ohm out and I think the tubes are self biasing. Can I run a 16 ohm cab off of it. I've heard that a less hardy amp would blow but peavey's are supposed to be pretty forgiving.
thanks
Amazing, and stickied!
My butcher blew a 1 amp fast acting board fuse. I read they should be slo blo since fast acting fuses can just pop in a healthy amp. Does this ring true with you?
Quote from: spookstrickland on February 12, 2011, 05:52:48 PM
Hemi,
Great thread! what do you know about the Peavey VTX head. It has a 4ohm out and I think the tubes are self biasing. Can I run a 16 ohm cab off of it. I've heard that a less hardy amp would blow but peavey's are supposed to be pretty forgiving.
thanks
The Peavey manual specs it into an 8 ohm cab at the Lo power setting, my gut would say 16 might be a little high, especially as it thas all that self biasing transistor stuff.
Two solutions:
1. Call or email Peavey, they are pretty responsive, I think now they make you sign up for their support forum to ask a question, but it still works.
2. Easy one, rewire the cab so it is 4 ohms, or make it switchable.
Or you could buy one of Weber's impedance matching transformers $48, and be able to run any load you like within reason
(https://taweber.powweb.com/store/wzc100.jpg)
The guys on the Peavey board are VERY helpful. You'll get several immediate responses, and there is a huge archive of owner's manuals on the site as well.
Quote from: nonoman on February 12, 2011, 08:45:02 PM
My butcher blew a 1 amp fast acting board fuse. I read they should be slo blo since fast acting fuses can just pop in a healthy amp. Does this ring true with you?
Slo Blo and Fast acting fuses both belong in an amp, on different sides of the Power transformer usually, but if you are talking about F1 which is the only 1A fuse I can see, then according to the schematic it's a Slo-Blo.
http://music-electronics-forum.com/attachments/11449d1288300024-peavey-butcher.pdf (http://music-electronics-forum.com/attachments/11449d1288300024-peavey-butcher.pdf)
Unrelated, this just looked cool
http://www.davidsonamp.com/woodland_gallery/gallery_butcher.php (http://www.davidsonamp.com/woodland_gallery/gallery_butcher.php)
This was my butcher, at one point. Never had an issue with it. Never popped a fuse, nothing. Soon as nonoman got it... problems galore. Wtfm8?
Thanks Hemi,
I got two cabs so I can just run them in Parallel for 8 ohms and the low power mode is damn loud anyway.
Thanks again
Quote from: Hemisaurus on February 12, 2011, 08:51:35 PM
Quote from: spookstrickland on February 12, 2011, 05:52:48 PM
Hemi,
Great thread! what do you know about the Peavey VTX head. It has a 4ohm out and I think the tubes are self biasing. Can I run a 16 ohm cab off of it. I've heard that a less hardy amp would blow but peavey's are supposed to be pretty forgiving.
thanks
The Peavey manual specs it into an 8 ohm cab at the Lo power setting, my gut would say 16 might be a little high, especially as it thas all that self biasing transistor stuff.
Two solutions:
1. Call or email Peavey, they are pretty responsive, I think now they make you sign up for their support forum to ask a question, but it still works.
2. Easy one, rewire the cab so it is 4 ohms, or make it switchable.
Or you could buy one of Weber's impedance matching transformers $48, and be able to run any load you like within reason
(https://taweber.powweb.com/store/wzc100.jpg)
Quote from: Hemisaurus on February 12, 2011, 09:16:36 PM
Unrelated, this just looked cool
http://www.davidsonamp.com/woodland_gallery/gallery_butcher.php (http://www.davidsonamp.com/woodland_gallery/gallery_butcher.php)
That IS cool, wish I could do that, lolz.
Thanks for the fuse help also.
SunnO))), I'm putting about 8 hrs a week on this thing, or do they usually wear better w/o incident than this?
Now you say older amps marked with a jack that says "Ext Speaker" has a different set if rules. Could you explain those rules in detail Hemi?
I said might have a different set of rules, it differs from amp to amp, model to model.
If you have the specific make and model, it's best to check the schematic.
Some are wired in series with the main speaker / speaker jack, rather than in parallel like a modern one. I actually saw a solid state Rickenbacker where using the EXT Speaker jack would actually reduce the output power, as you were increasing the impedance on the output jack, weird huh :o
(http://dub.greboguru.org/series-out.png)
I'm a tube noob, so somebody needs to school my ass on attenuators. Will any one do? Should it match wattage and impedence? Hellllllp! Just got a VTM60, and even the lowest of volume settings rumbles the shit out of my hoose. I'd like to get optimum tone even whilst just piddling around...is this the way to go?
Almost anyone will do but some may sound better than others.
At it's simplest the attenuator is an extra impedance you add onto your speaker / amp that wastes some of the amps power and prevents it from reaching the speaker.
As long as the attenuator is within the amps impedance range it should be fine, however a purely resistive attenuator, may not make your amp sound and respond the same, as one that uses inductance to closer model the response of an actual loudspeaker.
Beware the $15 attenuator box on eBay. A buddy of mine bought one of these, and it's just a 100K pot in a little box. Connect this to a tube amp and you'll blow something valuable, like a set of tubes, or your transgormer.
Ted Weber .com has some inductive attenuators.
Quote from: Hemisaurus on February 15, 2011, 03:59:39 PM
I said might have a different set of rules, it differs from amp to amp, model to model.
If you have the specific make and model, it's best to check the schematic.
Some are wired in series with the main speaker / speaker jack, rather than in parallel like a modern one. I actually saw a solid state Rickenbacker where using the EXT Speaker jack would actually reduce the output power, as you were increasing the impedance on the output jack, weird huh :o
(http://dub.greboguru.org/series-out.png)
i had one of those ricks. i sold it to a kid who was from vietnam. i wonder whatever happened to that amp. it had the craziest "dying battery" sounding fuzz.
you guys are such brainiacs..please tell me why i can take my bass and plug it into any amp and it sounds like me..i honestly thing some of the amp stuff is total bull. you pick an instrument that fits you..hence me customizing my j bass. after that ill sound like me no matter what amp i run through..maybe its just me..carry on.
Quote from: mortlock on February 17, 2011, 11:37:02 PM
you guys are such brainiacs..please tell me why i can take my bass and plug it into any amp and it sounds like me..i honestly thing some of the amp stuff is total bull. you pick an instrument that fits you..hence me customizing my j bass. after that ill sound like me no matter what amp i run through..maybe its just me..carry on.
Yeah, this is one of those DUH!!! questions.
Of course it's going to sound like you, it's you playing. If I were to pick up your bass, plug it into any amp, it's not going to sound like you atall.
The point of this thread was to prevent people blowing shit up, and save them a few bucks in repair fees.
If you can point to the total bull, maybe I can explain it to you.
thanks for clearing that up..i really wasnt trying to start any trouble..it was more of a drunken observation..
How would I wire in an expression pedal input to a trem pedal? I doubt I can afford one that comes with one, already... haha.
EDIT: Can I send wires from the wiper/case to a jack, and plug a pedal into it, and have it change value, or will it stay the same since the wiper isn't moving, for realz?
Also, home-made expression pedals. DOING SHIT ON A BUDGET THAT HAS NO ROOM FOR EXCESS SPENDING.
Tech Q,
I built up a germ fuzz face from byoc. Sounded shitty then paid for a new set of germs and voila it sounded like it should-fantastic. I guess he thought he would send the crappiest sounding germs to me and perhaps I wouldn't know the diff?! Anyway, the pedal comes with sockets for the germ transistors so you can fast swap'm with silicon and perhaps more importantly you don't damage the germ transistors when soldering them in place with over heating. The problem is that my germs don't contact the sockets well ie it won't function. Should I solder them in and ignore the possibility of damage to a great sounding set of germs or is there a solution I'm not seeing?
Just use a heat sink. Take a pair of hemostats and clip them onto the lead, so that they absorb the heat..
got it.
Quote from: Hemisaurus on February 12, 2011, 05:36:46 PM
- Never run a tube amp without a speaker attached
- Always set the impedance switch to the proper value, or use the proper impedance of speaker, unless the manufacturer says otherwise (some Peavey tube amps have a minimum impedance but don't care otherwise)
Additionally, if you for some reason have to run mismatched impedance cabs, it is better to have the speakers impedance be lower than what the amp is rated for (this would be opposite of the rule for solid state). In general, people seem to think a 2:1 mismatch either way is tolerable but you will get maximum volume and life from your tubes if you match exactly.
See if I understand correctly. You're saying, for example, an 8-ohm tube amp into a 4-ohm cab is ok, if less than ideal? While an 8-ohm solid state should run into 8 or 16 ohms? Or am I totally out in left field?
Yeah, if you have an eight ohm tube amp, a four ohm load should be OK. The way it works is a tube amp puts out about the same amount of power no matter what load you plug into it. So if you have too high a load, it is sort of like shoving ten pounds of shit in a five pound bag. Too low and it is like shoving five pounds of shit into a ten pound bag so it works but you're still using the wrong bag... Having no cab attached is like shoving infinity pounds of shit into a sheet of plywood. So that's my colorful simile of the day even if it's not strictly true in a technical sense.
It varies a lot by design and manufacturer though. Some Fenders you can abuse them w/ all manner of wrong impedance, low and high, and they might burn through tubes a bit faster but they'll live. Marshalls, on the other hand, are pretty notorious for being picky. For myself, I never mismatch if absolutely necessary (using a backup head at a show, &c.).
Solid state heads will put out as much power as they can dependent on load. If you plug a hundred watt amp that wants to see an eight ohm load into a four ohm load, it will try to output more than a hundred watts worth of signal and then it will overheat, maybe blow a fuse, maybe let the smoke out.
Never do it (unless the manufacturer says otherwise).
There are some designs that will tolerate a mismatch quite happily, some Peavey tube amps, I forget which say any impedance above 4 ohms, others will go POP quite happily. Unless you can predict which it is, or pay the damage if you are wrong, don't do it.
+1 on never mismatching.
70's Ampeg v4 (the one with the distortion channel 1 clean channel 2)
Was sounding like shit. I play it a lot tubes had about a year of abuse so I auditioned all new tubes (pre and power).
Sounded amazing. Like a new amp. Real tight. Very good range. No mud. Very clear even with a lot of dirt.
Play a show and have a practice everything's great.
Then all of a sudden its back to sounding like shit. Very loose and muddy. Not clear. No low mid or high definition. Just loud vomit.
All tubes seem uniform in color and are in there sockets tight. I havent changed anything as far as my set up. Same guitars, same pedals, etc. And its back to the same way it sounded before new tubes.
Any thoughts. So frustrating and sad to sound like shit when you know the potential of your set up. I mean it sounded so fucking good with new tubes I need to capture that sound again. Im chasing the dragon.
This is either a take it to a tech, or be prepared to do a bit of work on it situation. You've done the obvious stuff? None of the tubes are red-plating?
You basically need to check if the amp is eating the tubes, you'll want to check the bias, preferably indivdually on each power tube, and also if you can, narrow down the area which is giving you the problem, pre-tubes or power tubes (swap pre-tubes one at a time, but power tubes in sets). If it's a problem in the preamp tubes, it's either you got a bad tube, a fault in the amp, or maybe it got knocked while the tubes were hot and one of the tubes is now bad.
If it's in the power section, and the bias is all A-OK, it could (hopefully) just be a bad set of tubes, happens all the time, I re-did Freightshaking Bob's amp recently, he bought a quad set of EL-34 GrooveTubes from GC, they crapped out after a couple of practices, on the day of a show, thankfully we'd kept the old tubes, and it sounded good with the old power tubes and the new pre-tubes in, so we ran with that and he exchanged the tubes later at GC. So I'd hope it's just dodgy tubes, rule that out first if you can.
If you eat a third set of power tubes, and the bias is still OK, I'd want to soak test the amp, run it hard for a good long time, whilst monitoring the current through those power tubes.
Of course this is all from no knowledge whatsoever of your amp, I'd run a full set of voltage checks on it, check the ripple on the supplies to see if your resevoir caps are going bad, etc.. etc. as well.
Thanks hemi. I brought it to my tech. Hopefully he can get to the bottom of it.
Quote from: ROWDYBEER on March 17, 2011, 09:01:10 AM
Thanks hemi. I brought it to my tech. Hopefully he can get to the bottom of it.
Let us know what he finds, if you can, ta :)
Anyone have a Matamp GT120 they've mapped the schematic on? I found a pic of one line, but none of the values are readable...
You've seen that one too ;)
Best I'd suggest is, either talk to Electric Amp, or Matamp, or look at the Orange Field Guide and guess the rest.
Are you repairing or cloning?
Hoping to clone...
Quote from: Wesogkan on March 17, 2011, 05:46:35 PM
Hoping to clone...
Well you can get the basic ideas from the orange field guide and maybe Webers 6O100.
You can see the difference, sort of, on the schematic. The original Orange has one rotary switch, the newer Matamps (and Electric I think) use two which switch in various RC combinations to monkey with the tone, the phase splitter and power sections are pretty standard.
What are you planning to use for power tubes and transformers?
Maybe someone would be willing to supply some detailed gutshots?
I'll probably want el34's...not sure about the transformer yet, but a big hairy one for sure.
Well a quad of EL-34's you could get away with any 100W output transformer really, though some like more iron in their core (the orangefg guy wound a 50W tranny on a 100W core). You could even get the Weber Orange kit and just modify the input section, use the standard Baxendall tone stack (bass / treble), and replace the mid pot with a second rotary switch like the Matamp has. I don't know if it's cheaper to buy their kit or collect the parts, or scrounge up the parts used.
https://taweber.powweb.com/store/kits_60b.htm#6o100 (https://taweber.powweb.com/store/kits_60b.htm#6o100)
They just use the same 100W tranny for all their 100W heads I think.
Freakin' sweet...
Quote from: SunnO))) on March 18, 2011, 10:15:38 PM
Quote from: TheWolfIsLoose on March 18, 2011, 09:00:57 AM
Freakin' sweet...
Pics or it didn't happen.
Calm down, I doubt even John McNeece (http://www.classaelectronics.com/aboutus.html) can wire up a tube amp in an afternoon, I think he was maybe just expressing excitement ???
Quote from: Hemisaurus on March 19, 2011, 07:46:10 AM
Quote from: SunnO))) on March 18, 2011, 10:15:38 PM
Quote from: TheWolfIsLoose on March 18, 2011, 09:00:57 AM
Freakin' sweet...
Pics or it didn't happen.
Calm down, I doubt even John McNeece (http://www.classaelectronics.com/aboutus.html) can wire up a tube amp in an afternoon, I think he was maybe just expressing excitement ???
ACTUALLY, HE CAN! haha, John is my amp tech in town. I'm going to Atlanta to see Loss tonight. hate me.
Nah, I just feel sorry for John, having to deal with your collection of Beta's ;D
He hates them. :(
I love them so much, though. They rarely go down anymore.
Not sure if this is the proper thread but you guy s seem to have a great deal of knowledge on these things. Sorry if i posted in the wrong spot.
I have a strange buzzing going on with my cab. I have an older Sunn Sorado cab that i recently dropped 2 EV SRO 15's into. Any way when i play it, i get a strange buzzing/farting sound from the top speaker that will increase in volume as you turn up the volume on the head. I took the back off and examined the speaker and found no holes. Tried it again and NO NOISE! Yesterday i plugged in and the noise is back.
Did i wire it up wrong? Are the speakers to big? Help me Hemi..you are my only hope!
BTW i am using a Sunn Coli 300.
It's probably a loose something, rather than a broken something. Old cabs are fun that way, not only do you have to make sure that the speakers are nice and tight in the cab (and hopefully you have some kind of gasket on the mating surfaces, if not use some weatherstripping?) you have to go round the cab and check that the panels are still nice and tight against each other. If you can get someone to play through the cab, whilst you go around pushing where it seems to rattle, 'til you find your buzz.
Loose mounting holes, loose corners, loose handles, glue joint gae up the ghost
... 90% chance it is something loose.
I will check that out and get back to you guys. Thanks. This is a rear loaded cab, should i use some kind of gasket for the speakers?
Problem identified! The center dust cover on the speaker came unglued and slide beneath the grill cloth and the speaker. My 5 yr old daughter was "helping" me and she noticed it rattling inside the grill cloth. What do i use to re glue it and will it hurt to play with it off?
A dust cover is just a dust cover. I had an Ampeg 215 that had NO covers. Both coils were completely exposed, but it didn't affect the sound whatsoever.
Dustcaps are only really important in PA cabs that move a lot of air. There they function to help keep the driver air-tight and to pull and push cool air into the driver core. I've know a lot of 2x15 cabs that didn't have dustcaps and ran just fine.
Rubber cement is generally used to hold them on, if you are worried you can buy stuff from http://simplyspeakers.com (http://simplyspeakers.com) last time I ordered dustcaps from them they also included a tube of adhesive, so I assume they sell it.
I think I might have asked this on the old forum right before it exploded but... I plugged an amp which turned out to be all kinds of hosed into a speaker cab and it didn't make any sound but then smelled kinda funny immediately after (but no smoke at least). After that, none of the speakers made a sound when plugged into a known working amp and if you push on the voice coil it feels like they kind of grind against the sides. I re-speakered the cab since I didn't really like the sound of it anyway but I kept these speakers on the off chance they could be re-coned or otherwise fixed. So is there any chance these speakers could be re-coned or otherwise fixed?
Also, if anyone in Chicago wants four possibly completely ruined speakers from a 4x10 Travynor cab, they are all yours if you wanna pick 'em up.
Any speaker can be reconed, unless it's physically deformed, I'd suggest you take it to Van L. up on Western, Near Foster I think (it's been a good 14 years) and ask them what they think.
Looks like they are still there http://www.vanlspeakerworks.com/contact.htm (http://www.vanlspeakerworks.com/contact.htm)
Van L Speakerworks
5704 North Western Avenue
Chicago, IL 60659
773-769-0773
Store Hours:
Tuesday 11 a.m. - 8 p.m.
Wednesday 11 a.m. - 6 p.m.
Thursday 11 a.m. - 8 p.m.
Friday 11 a.m. - 6 p.m.
Saturday 11 a.m. - 3 p.m.
Closed Sunday and Monday
(I'll usually answer the phone on those days too)
I use two part epoxy and the corner of a towel to put dust caps back on. Its strong enough to hold em tight. Just dont go crazy with it. A thin layer all the way around is enough. I am going to disagree with Herb, and advise strongly to put it back on. It's there for a reason, or else they wouldn't come with dust caps... my .02$...
I got everything back together and i think i may have hooked it up wrong. It sounded fine without the dust cap but now it is crackling like there is a loose wire or something in that respect. I wander if i broke off a wire that leads to the wire hookups for the speaker. I took the speakers out of my Sunn cab and put them in my Fender Bassman 215 cab (Sunn Guitar Transducer and Jensen Special Design) just to have a second working cab and it sounds awful! Those speakers rattle so bad! The speakers are front loaded and i think i may need some insulation tape around them.
Tomorrow is another day....
could be you didn't seal that dustcap on right and it's buzzing off the cone, check for gaps on it.
I never put it back on.
That rules that out then :D
A crackle, if your sure it's a crackle, and not a rattle or a buzz, does tend to be more likely to be electrically related, so yeah check all your wiring, make sure the jack socket is nice and snug and all that good stuff, before deciding to confine that speaker to the trash.
Ok, the game plan has changed...I'm close to possession of a Sunn 2000s that needs rebuilding. I'm thinking of doing it up pretty original, but with the Green/Orange overdrive in it. Crazy? Would probably need too many knobs on the front panel...oi. I may need a separate pre-amp unit.
Maybe not, if you do the Mat pre, you could instead of doing a 4 position rotary drive, do two toggle switches instead for stage/studio and normal/brite put them in two of the 4 input jacks, and use the contour as the FAC, hmm still need a pot space for boost, suppose you could take out the bass boost switch, and convert that to you fifth pot? It could look pretty natural that way and all the labels would still make sense.
The trouble is your short a half tube in the preamp section. :-[
Herbie, Why didn't you ever build that beta bass preamp? You ought to hook me up with one, in rack mount form. I have a 2000 watt power amp waiting to devastate nerds who like dubstep...
;D
I never needed it, I found a ready-made solid state preamp that worked fine, that I already owned that was part of something else.
Then I saw this guy, who had made a tube preamp for his bass, just taking a regular tube amp schematic and skipping all the pesky power tube stuff, and I thought well that's simpler than a bunch of chips, though it takes up more space
(http://farm3.static.flickr.com/2517/3935776448_cbce9aaf9c_o_d.jpg)
so I started scribbling ideas down, looking for a cheap transformer etc.
Then I thought, well shit, if I'm going to all the trouble to wire up a preamp, and it's not going to fit in a 1U, why don't I make room for the power amp section too, so I sketched all that out, came up with a good way to make my own chassis, started looking at bigger transformers, trying to decide between KT-88's and the more esoteric, but cooler looking 807's.
Then I found a circuit I built into my bass, which meant less to carry, so I didn't need a preamp atall ;D
and during all this time I was still fixing other peoples amps, doing my 9-5, playing in a couple of bands, refurb'ing my Alamo, becoming a dad, doing sound for people etc. etc.
what size/ type of wire do i need to re wire a cab? I think the wiring in the Sunn Cab has be soldered and spliced too many times so i think i will just rewire the thing and hopefully it will stop my problems. any suggestions from the techs?
16 gauge would be fine, 14 gauge if you're nervous, 12 gauge or lower if your hardcore :)
Type of wire, any kind of flex, not solid core wire or shielded cable.
Strip an old extension cord or power cord and use that. Or buy some lamp flex or speaker wire, or use the stuff you can get at the auto store.
I use super high quality wire on everything I use.
What would it entail to have one built? I want the PB-20/10 but they're crazy hard to find for under 500 bucks.
I'm also wanting to throw it in front of my JCM800...
Take a Beta (you have a bunch), adjust to suit. Make a box for it, or hacksaw the frontpanel down to 19" width
Look at the service manual, there's the preamp board, and the power board, all the preamp board requires is +/- 15V. Either disconnect everything else on the power board or make your own +/- 15V supply, whatever you want.
Or buy that Sunn/Muff thing Baltar posted months back.
(http://correctsoundcustom.com/img/Devices/MH_400.jpg)
Quote from: Hemisaurus on March 23, 2011, 10:00:02 AM
16 gauge would be fine, 14 gauge if you're nervous, 12 gauge or lower if your hardcore :)
Type of wire, any kind of flex, not solid core wire or shielded cable.
Strip an old extension cord or power cord and use that. Or buy some lamp flex or speaker wire, or use the stuff you can get at the auto store.
Thanks you sir. i was going to stop at the local Radio Shack and see what sort of stuff they carried.
I don't want to hurt one of my already-working betas :(
I just want to be able to super-power the fucker so I have sufficient low end wattage. Maybe if I find myself in a situation with 16 guitar cabs, I can use 2000 watts of power to level a small village or something.
Quote from: hayseed on March 23, 2011, 10:56:12 AM
Quote from: Hemisaurus on March 23, 2011, 10:00:02 AM
16 gauge would be fine, 14 gauge if you're nervous, 12 gauge or lower if your hardcore :)
Type of wire, any kind of flex, not solid core wire or shielded cable.
Strip an old extension cord or power cord and use that. Or buy some lamp flex or speaker wire, or use the stuff you can get at the auto store.
Thanks you sir. i was going to stop at the local Radio Shack and see what sort of stuff they carried.
Hardware stores carry lamp flex, and extension cords, dollar stores carry extension cords, auto stores carry hookup wire, if you can't make it to the shack. I'm working my way through a 50ft extension I bought at WalMart :)
Quote from: SunnO))) on March 23, 2011, 11:03:41 AM
I don't want to hurt one of my already-working betas :(
I just want to be able to super-power the fucker so I have sufficient low end wattage. Maybe if I find myself in a situation with 16 guitar cabs, I can use 2000 watts of power to level a small village or something.
So pick up a non-working one, one where the power section is blown, but the pre is OK preferably. Or just use the Accesdory out on one you already own, doesn't that work?
Or, distilled down to it's simplest, 3 hex inverters in a pedal.
(http://runoffgroove.com/3leggeddog.png)
Quote from: Hemisaurus on March 22, 2011, 11:18:42 PM
Maybe not, if you do the Mat pre, you could instead of doing a 4 position rotary drive, do two toggle switches instead for stage/studio and normal/brite put them in two of the 4 input jacks, and use the contour as the FAC, hmm still need a pot space for boost, suppose you could take out the bass boost switch, and convert that to you fifth pot? It could look pretty natural that way and all the labels would still make sense.
The trouble is your short a half tube in the preamp section. :-[
Oooohh..that might work. On the other hand one of my V4's is already wired up for an external pre-amp...so I could use a pre-amp with 2 different amps if I went the other route. Decisions, decisions...
That almost makes it sound like it would be worth building a separate power amp section, and have different pre sections you can plug in. I know Randall did something like this, but I'm thinking more like the original OR-200 Lead where it's an OR-200 Slave with a preamp built onto the front panel.
(http://www.planetoftheamps.com/orangemat-200-008.jpg)
(http://www.planetoftheamps.com/orangemat-200-010.jpg)
(http://www.planetoftheamps.com/orangemat-200-011.jpg)
Ok Hemi...help me before i jam my bass through my cabinets!
I completely rewired my Sunn Sorado cab and returned the original speakers to their home. Sounds better, has a little crackle but i think my head may need a good cleaning. Now here comes my problem...I rewired my Fender Bassman 215 and put the EV SRO's back in. When i plugged in , i got no sound at all BUT my Power Amp Limit light on my head was kind of pulsating(not staying on constant but enough to worry). I disconnected the cab and plugged into my head and the Overload light peak when i played hard, like normal.
What the hell did i do?
Thanks for answering my dumb questions...i am a novice at fixing/upgrading stuff
Sounds like a short, or maybe a duck, probably a short though :D
Oi...trying to narrow down the best preamp to copy (will be used with a Sunn 2000s AND/OR an Ampeg V4 that will have plug ins for it). Either a Matamp or Orange gain...donno what sounds best circuit-wise.
That's kind of like asking someone what your favourite flavour of ice cream should be, I'm out ::)
Sunn Cab is rewired and happy for now. Fender Cab is as dead it can get....time to walk away for a bit!
Quote from: Hemisaurus on March 24, 2011, 11:22:42 PM
That's kind of like asking someone what your favourite flavour of ice cream should be, I'm out ::)
I know...arghhhh.
who does cheap re cones or is it cheaper to re cone my 15's myself? OR is it cheaper to just buy new speakers?
I am researching this stuff right now. Seems like re cones go about $75 -90 by someone else or $60- 75 for a kit. Not sure if i am checking the correct places.
I did find Eminence Alpha 15A's for $57.99. I realize they are not the best speaker BUT are they worth it to buy them instead of repairing what i have?
Since I've never found a source for generic cones and voice coils on this continent, I've found unless it's some kind of special vintage speaker, or a really high powered woofer, it's cheaper to replace.
You can always keep the old ones, and recone them at a later date.
Yeah, I have a stack of speakers to recone, if I ever find a source of nice cheap generic parts :-\
I use the Eminence Delta 15Bs in my bass cab, and they're fucking quality. I don't care what people say. They have survived two-ish years of being SLAMMED with square waves.
I just got 2 Eminence CA 154 15" speakers for an old gutted Ampeg B25-B cab $50.99/ea. Not sure how they sound yet, one of them arrived with about 1" of the foam glued on wrong where it meets the speaker rim, had to send it back. Waiting for replacement...*sigh*
Seeing as we're talking speakers, has anyone tried the Carvin Neo's?
I was thinking about redoing my 4x10 with them, back when I was using it for gigging, they have 12, 15 and 18"s in the Neodyium as well, very reasonable, like Carvin usually is, they're standard drivers are pretty bulletproof.
I'm not sure what i am gonna do with my speaker problem yet. I may just try to sell the blown stuff to a local guy and sell the Bassman cab for WAY less than what i bought it for. I am gonna clean up my Sunn 2x15 and sell it as well i think. I just bought a Peavey 1510 T-Fest and i am picking it up this weekend. Very cool cabinet- 2x15, 2x10 and 3 tweeters! Can't find any info on the thing on the internet at all but it just so damn cool!
OR... i may try a re-cone on some of the speakers just to learn how to do it for myself. Why not? Plus i feel a little guilty for trashing 2 perfectly good SRO's that sounded fine where they were in the first place.
The why not might be that an EV recone kit, the cheapest I can find is $60, well on eBay there's one for $40 + $10 shipping.
You might be able to piece something together cheaper from Mat Electronics (http://www.matelectronics.com/acatalog/MAT_Electronics_Speaker___Accessories_151.html) they now seem to be carrying a generic 2" voice coil, so maybe there's hope for my broken speaker stack yet.
Ah bollocks, no, I need a 2.5" voice coil :(, anyone know a source ???
Can u explain how i can do "mated ratings' if i changed out the speakers on the 1510. It has 2x15 , 2x10 and 3 tweeters. I am not entirely sure as to how to wire it or what wattage or ohm speakers i should be looking for.
Quote from: hayseed on March 29, 2011, 01:28:58 PM
Can u explain how i can do "mated ratings' if i changed out the speakers on the 1510. It has 2x15 , 2x10 and 3 tweeters. I am not entirely sure as to how to wire it or what wattage or ohm speakers i should be looking for.
Never heard that term before. I'd guess it maybe means make sure you don't get two different 15's or 10's or three different tweeters, keep them the same sensitivity as each other.
You're going way beyond what I can explain on a forum, without seeing it, maybe someone else will have a go.
Thanks Hemi. I know it is best to have the speakers matched but in cab with 2 different sized speakers, how does one match it all up? For example if the 15's are rated at 300 watt, should the 10's also be rated at 300 watt?
If it's just like an instrument cab, with no crossover, then yes you match them, or use the cab at the rating of the weakest link, if you had a standard 4 driver cab, all drivers 8 ohms, and you had 2 200W 15's a 400W 10 and a 100W 10, the weakest link is the 100W 10", as the cab is series/parallel wired, and the drivers all have the same impedance, each driver is getting an equal share of the power, so the maximum power you can run is 4 x the weakest link, so 4 x 100W so you have a 400W cab.
If you have a crossover, then it's all way more complicated, as different frequency ranges require different power levels, basically your bass drivers need to be big, but you mid-range less so, and your tweets even less. Go with the ratings of what was originally in the cab, you can't go over the power rating of the crossover anyway, as you will blow the crossover itself.
Seeing as Google just returns your request on multiple forums, go call Peavey and ask them what they put in it. 1-877-732-8391
i did. They have no info documented due its age. They said it was one of the first Peavey cabs built! The only info they had was it used CTS speakers and Piezo tweeters,4 ohms, and that i shouldn't be pushing more than a 100watts through it again due to the age. The guy i am getting it from uses the same head i do and said there is no problems(Sunn Coli 300) which leads me to believe that it may not have orig speakers in it. He is sending me more pics of it tonite. I will forward them on.
Thanks for the wiring info btw.
Quote from: hayseed on March 29, 2011, 05:34:21 PM
i did. They have no info documented due its age. They said it was one of the first Peavey cabs built! The only info they had was it used CTS speakers and Piezo tweeters,4 ohms, and that i shouldn't be pushing more than a 100watss through it agian due to the age. The guy i am getting it from uses the same head i do and said there is no problems(Sunn Coli 300) which leads me to believe that it may not have orig speakers in it. He is sending me more pics of it tonite. I will forward them on.
Thanks for the wiring info btw.
PM they guy called paul on the Peavey forum, he seems to have stuff they don't.
Help me amp wizards!
Plugged in tonight and noticed a very loud hum with some popping when adjusting the preamp volume on my 2204. The hum is loud in the lo-input and louder in the hi-input. Normally, I decided to fiddle around with the preamp tubes, put in a spare EHX tube in the V2 slot and sure enough it drastically reduced the hum to almost zero. Then after a few minutes it came back along with the popping in the preamp volume.
I noticed when I would touch my guitar cord on the lo-input the hum would stop and then start as soon as I took my hand off it. On the hi-input it would just buzz endlessly. I am guessing some grounding issues with the amp? :'(
Also when turning my amp off I noticed a clicking noise as if the tubes were being 'pinged' at.
What is going on? :-[
EDIT: Decided to reinsert the power tubes to see if that was the problem. Turned it on and there was a loud screeching hum. Turned it off.
Turned it on again, no sound, dead.
:'( :'( :'(
Tubes. Replace them all. Check bias.
Neither of the fuses blew?
It turns back on and all three preamp tubes light up. One of the power tubes do not. I am guessing it is the tubes and it is the end of their life.
Quote from: Instant Dan on April 05, 2011, 11:18:51 PM
It turns back on and all three preamp tubes light up. One of the power tubes do not. I am guessing it is the tubes and it is the end of their life.
EL34s? If that buzz went away when you touched anything involving the strings, there is also a ground issue. Report in when new valves are in place...
Little odd that you replaced v2 not v1 ???
If the buzz is louder on the hi than the low, it's going to either be in the very first tube stage, or outside the amp entirely. Did you have pedals in line? Were they connected to a power adapter?
Does sound like it's toasted now, if one of the power heaters has gone. Did youi try swapping them over see if the problem followed the tube? With the amp in standby, only the heaters should be on, so you don't risk toasting anything else, so go ahead and try it, if you like.
Yes EL34's, Ruby's to be exact.
Yeah I had pedals in line connected to a power adapter but even when i plugged straight in, it didn't do anything good, still lots of hum.
I didn't change tubes while in standby if that is what you mean, too scared after all the horror stories amp techs tell you of being electrocuted to death.
I hope you don't mean toasted in the sense I blew something other than the tubes. :-\
Well I guess that is what I get for messing with the tubes again late at night and tired. I was trying the switch around method that hemi recommended and I somehow (even with being ever so gentle) managed to snap off the main male plug of the EL34 tube into the tube socket (pic for reference)
(http://www.newoldsounds.com/images/large/T-RUBY-EL34-Q_LRG.JPG)
Now I am just going to leave this to the professionals and try and find a tube doctor in Houston and honestly there are none.
Geez, don't change tubes with the power on :o
Never work on your amp with the power on, unless you really know what you are doing.
I meant that you only need turn the amp onto standby, after you had swapped the tubes, you didn't need to turn it all the way on.
I didn't do that though, I changed the tubes while the amp was off. It was only after I powered it up and took it off standby did I notice a horrible screeching noise.
Thank goodness :)
No I was suggesting rather than turn you amp on all the way, which if you have a problem, can cause further damage, just turn it on to standby, and see which of your tubes was glowing, and swap around the one that wasn't.
If the problem follows the tube, bad tube, if it stays with the socket, bad amp.
Can't do that now
QuoteWell I guess that is what I get for messing with the tubes again late at night and tired. I was trying the switch around method that hemi recommended and I somehow (even with being ever so gentle) managed to snap off the main male plug of the EL34 tube into the tube socket (pic for reference)
http://www.newoldsounds.com/images/large/T-RUBY-EL34-Q_LRG.JPG
So I gathered :-[
Don't worry, it's not unheard of, the plastic base is usually just soldered on, the tube is formed around the electrodes, which are left sticking out, then the plastic base is slipped over and the pins soldered to the electrodes. Hopefully it can be fixed with some tweezers, and you won't even need to replace the socket.
If you blew the B+ fuse, it wouldn't turn on? Right?
The heater supply is separate, so the tubes would still glow, the bias supply is separate, so there may be some wackiness, but there shouldn't be any sound.
I took her to Jake at http://www.steamboatampworks.com (http://www.steamboatampworks.com) since I had heard from others in Houston he did great repairs and at fair price. Some of the other (older cats) actually refused my business, not going name names. Needless to say, I have little respect for them.
Check out his 'detuned' cabs and amp heads. Got me gassing for one of his 2x12's and Steamboat Classic 18. :o
refused why? seems an odd way to run a business.
every so often I feel I should just work on simple, single channel tube amps, no Mesa crap, no solid state Crate, but I never do :P
Quote from: Instant Dan on April 09, 2011, 12:05:48 PM
I took her to Jake at http://www.steamboatampworks.com (http://www.steamboatampworks.com) since I had heard from others in Houston he did great repairs and at fair price. Some of the other (older cats) actually refused my business, not going name names. Needless to say, I have little respect for them.
Check out his 'detuned' cabs and amp heads. Got me gassing for one of his 2x12's and Steamboat Classic 18. :o
What an adorable logo these amps have...
So I got one of these http://www.freepatentsonline.com/1922415.html
Hemi, Its a fucking public address system from the 30s, (my model is from 36) It has no values on the schematic. But it looks like it has been repaired in the 50s or 60s Due to the telephone wire in it(my brother said that, and he would know) I mean, it still has some of the cloth braided wire on it. and sprauge caps. its running a single 6l6 a 6j7 rectifier and a 5y3gt All Westinghouse.... The transformer looks like the old tweed fenders. I'll try and get a picture of it. it is sweet looking.
Would you be able to point me in the right direction to resurrect this REAL point to point amplifier(as in no boards)? It's so cool, I mean, I payed 15 dollars for it So I would be willing to build a whole new preamp just to play a little guitar n bass through it(or just guitar if it can't take the bass) I google image searched it but none of them date that early, mine is made of wood with only one row of 1/8th inch mono jacks.
Well it might be tricky to do it all online, certainly if you were local, I'd give it a shot.
That link really isn't showing me anything, but 6J7 should be the input tube, not the rectifier, the 5Y3 is the rectifier.
You should be able to get an amp going from the tubes you already have. Sharp cutoof pentode and whatever tone stack (if any) you want. It's like Sunn's suicide amp, without the suicide part. It's a 3 tube special, have a look at the Airline Wards schematic, different tubes but same type, 1 sharp cutoff pentode for a pre-amp, 1 beam pentode for the power amp, 1 rectifier.
(http://dub.greboguru.org/3-tube.jpg)
You might want to move the tone stack to past the preamp tube though, so where C4 is, put the tone stack (and volume) and lose the volume and tone stuff on the input. Adjust to suit ;)
Also found this link
http://music-electronics-forum.com/t8219/ (http://music-electronics-forum.com/t8219/)
the guys scribbled a rough schematic of something similar, but you say you have a schematic ??? pics ???
(http://music-electronics-forum.com/attachments/2714d1215396135-receipts004.jpg)
Does it work atall? I'm thinking from the thirties, it probably will need a cap job, NB 1936 is the first year for the 6L6, I looked it up, because I thought it was in the forties. I'd be tempted to leave it as much 'as is' redo the caps, try putting a signal into the grid on the 6J7 and see what you get.
Do some research on the xfmr or the unit as a whole if you can, PA drivers were sometimes designed for odd output impedances.
Post as much detail as you can, pictures part numbers, etc.
I don't know if it works, I was too afraid too try it out. also 2 wires disconnected when I opened it up. (well I had to clip them) It did have like a 3 inch speaker in it to talk into and a flapper to press down and talk, but I somehow misplaced it. I did notice on the old(and decrepit) power cable it was burned between the two prongs. It is sitting on my workbench open right now.
Here is the patent number 1,922,415 us patent. That is all the info I can find about it. the "schematic" doesen't have any values so it isn't much help to me.
Working on pics right now.
I'm not an expert on the US patent system, but I believe it's more to cover the method of an implementation than the implementation itself.
ie. a system using vacuum tubes that allows a microphone, or microphones to drive multiple loudspeakers.
You may find that same patent number in a lot of PA amps, anyone got one can confirm?
Even without values, a schematic can be a handy thing. A schematic without values, kinda like a road map without street names, you can get from start to finish, but if you get stuck in the middle you have to look around for a 'landmark' (like a tube) to find your way. I await the pictures :)
http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1676-1.jpg (http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1676-1.jpg)
http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1679.jpg (http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1679.jpg)
http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1680.jpg (http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1680.jpg)
http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1684.jpg (http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1684.jpg)
http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1689.jpg (http://s1129.photobucket.com/albums/m508/SpaceTrucker89/?action=view¤t=DSCN1689.jpg)
Here you are.
As you can tell its like a P.A in a school or office. And it is very heavy for its size. but the wood is so pretty, its not a laminate its actual wood and a very light wood at that. Like cherrywood or something.
Info on a piece of paper attacted to the inside of the amp;
Teletalk model 224 m
pilot bulb use no. 44 westinghouse or equivalent 6.5volt at 250 mills bayonet socket.
ac 50/60 cycle 115 volts 30 Watts
Notice uses about 15 watts in idle position
Licensed by Reyarch products inc. under US patents of American telephone and telegraph company and western electric company inc
Made by webster electric company Racine Wisconsin U.S of America.
Websters are very common, lots of people convert them.
It does look like that model has been bastardised a bit, those aren't all the original caps, it does look a bit of a rat's nest, and obviously be careful of the uninsulated cap on top of the 6J7 as that carries the plate voltage I imagine.
No pic of the schematic? In the 9th and 10th pics, is that the 6J7 on the right?
Mainly you need to make sure the amps in good enough health you can turn it on. You need to have an appropriate load on the output. You need to make a suitable input network, might just need a resistor on the control grid of the 6J7.
OK that transformer hooked to the 6J7 was freaking me out 'til I checked the datasheet.
The top hookup is for the grid, so that's the input.
WARNING: What I'm going to say next could very well kill you, or worse, damage the amp!
If you have a big set of brass balls (well insulated of course), you could just say fuck it, hook a speaker up to the back (any mention of impedance?), get a few clip leads and jump wire a cable to the top of that tube, maybe via say a 22-68K resistor and chassis ground (removing the connection to that weird transformer)
I would do this, but of course I have a variac on my bench, and would check for dangerous voltages before doing it.
The safe way would be to first check for any suicide caps, that connect the mains to the chassis, and remove them.
Then fit a 3 wire cable with a chassis ground.
Then try very hard to find information on the load impedance, there may be marked taps somewhere?
Then, hook the amp up to a GFI before turning it on.
All the rest depends on what kind of test gear you have.
You can power it up without the 6L6, and thus save the transformer from damage, whilst you inject a signal into the 6J7, you can use a voltmeter on the cap of the 6J7 to ground check for any DC voltage. You could try running a signal through the mic transformer.
Basically, if you can't get info on that output transformer you can go from a potential amp to a pile of toast in a few seconds flat :(
Well I got a response back from the guy today. He said there was some grounding issues but easily fixed and just needed new tubes. I lucked out. :P
Cool 8)
You realize there's only so much we can do via the internet, right ;)
Yep, hence why I need to step up my gear repair knowledge.
Quote from: Instant Dan on April 12, 2011, 02:33:28 PM
Yep, hence why I need to step up my gear repair knowledge.
Best place to start (for free)
http://www.diyguitarist.com/Misc/J_Darr.htm (http://www.diyguitarist.com/Misc/J_Darr.htm)
The 6j7 is opposite the big transformer, Where all the big caps are.(left hand side)
So, what if I don't have any test gear. Except like, alligator clips, a volt meter, solder gun, and Balls to spare. So what your suggesting is put a gator clip on the top of the 6j7 as a signal-input?(don't you need two wires for that?) and put a beater speaker on one of the six outputs(Not shown)? and hope for the best?
Along with doing the safe thing and hooking up a 3 prong(grounded to chassis, like grinding/sanding a shiny part or just strait on it?).
P.S 15$s ain't too bad is it?
Oh yeah and I noticed another Hole in the chassis, that I could fit a preamp tube socket into.
I have not found any info on the output transformer yet. Only info I could find was 1800 ohms on a single (I want to say field coil) speaker from a webster electric amp from 1935, that was like a organ amp or steel guitar amp. I hope that isn't the case.
Quote from: Hemisaurus on April 12, 2011, 02:50:05 PM
Quote from: Instant Dan on April 12, 2011, 02:33:28 PM
Yep, hence why I need to step up my gear repair knowledge.
Best place to start (for free)
http://www.diyguitarist.com/Misc/J_Darr.htm (http://www.diyguitarist.com/Misc/J_Darr.htm)
Great link!
This may have been asked already but; what is a good mod i can do to my RAT2 to make it more bass friendly? Where does one get the parts to do so and do you have any suggestions?
Quote from: hayseed on April 12, 2011, 03:16:58 PM
Great link!
This may have been asked already but; what is a good mod i can do to my RAT2 to make it more bass friendly? Where does one get the parts to do so and do you have any suggestions?
Bass friendly usually means upping the values of the capacitors in the signal path.
I don't have a RAT 2 schematic, this guy has a mod'd one.
http://illuminist.tk (http://illuminist.tk)
Looking at an original RAT schematic
(http://www.diystompboxes.com/pedals/PCRAT1.GIF)
I'd want to up those two .022uF to .22uF and see how that sounds.
Then maybe change the .0033 as it's part of the filter circuit.
Answering myself, I found a better RAT schematic.
(http://www.happybob.com/rstrand/rat/pcratrev.gif)
according to the blurb, RAT 2 is the same as the Turbo Rat but with 1N4148 diodes for clipping.
With that, I'll stick to my original opinion on changing those 2, maybe 3 cap values.
or you could try this guys mod, sounds like he plays jazz guitar ::)
http://www.diyguitaramp.com/rat.html (http://www.diyguitaramp.com/rat.html)
Ok, some good news and bad news.
Got the amp back today and still had some hum left >:(
Notice when I changed inputs from Lo to Hi, the hum disappeared on the Lo input but still remains ,but is manageable, on the hi input.
The only thing I can figure out is maybe it is the cables I am using (they're almost ten years old) or it is just the room I playing in. The thing is, I don't remember with my electric amp 4x12 with mesa head being that noisy. I doubt it is the cab as I ran my epiphone valve through it and it sounded fine, no noise.
Maybe it's just the head >:(
Still sounds good though!
EDIT: The more I listen to youtube stuff online. It sounds like that is the nature of the beast if you have it in the hi-input. Not mega quiet.
If the hum is really bugging you, borrow a power conditioner, see if that makes a difference. If it does, great.
Nah, I think it has to do with the room as I noticed when I turned off the lights in the room, the buzz/hum went to zero on both channels.
That being said,
Fluorescents?
I bought a power conditioner today, mother fuck of GOD! I have NEVER heard my beta leads without a shitload of noise. I LOVE IT. Everything also sounds a tad louder, and clearer. Time to EQ again...
Quote from: eyeprod on April 18, 2011, 09:48:40 AM
I mentioned one of my "mods" a month or two back and finally got around to opening it up and taking some pics. Well I had this weird feedback loop going on, but didn't know what exactly was happening. I figures it out this weekend and it's a new mod that I have not found on the net. I rigged it up in a switch, so I can use the muff as normal, or put it into super self oscillate mode, as I've come to call it. I have a voltage drain on my muff, and no tone stack. That might have something to do with how mine works. Turn the voltage and sustain up to about 3 o'clock, and the thing starts to self oscillate and sounds like a synth. Can be made to sound theremin-like by varying the sustain level. You have to do it manually, but it makes for a nice "vibrato" effect that also changes pitch. When playing notes, it sounds like an octave fuzz out of control, but you don;t even have to play any notes and the thing takes off on it's own. Even if the voltage and sustain is low enough to avoid self-osc, it still has a much more fuzzy character than in normal mode. The other weird thing about it is that even when the pedal is off, but in super osc mode it still affects any pedals that are before the muff in the chain. I had my fuzz rite clone before it yesterday and it made the fuzz rite even more fizzy and sputtery. Pretty cool. Thought I'd share
(http://loud-art.com/muff1.jpg)
(http://loud-art.com/muff2.jpg)
So, it's a wire to the first diode from the input jack. That's it.
I think it's time to put a three-prong on my Sonaro. It shocked the everliving fuck out of me tonight.
Instruction is required, possible consequences for switched wires, will it mess up the value, whatever?
First find me a schematic :)
I'm looking at the schematic for the 2000s as it's meant to be similar?
(http://sunn.ampage.org/site/schematics/220s.gif)
I'm not sure about those weird symbols, like a cap in a circle? and whats the other one an extra outlet that's switched?
Anyhoo, if the Sonaro has a polarity switch on it, it's similar enough to say this, get rid of the polarity switch ;D
Basically you have a cap there that's connecting the AC line to ground, ostensibly for getting rid of noise, but it's a bad, bad, idea when the cap shorts, owch time.
What to do, the 3 wire should just connect to the primary of the transformer, looking at that diagram one pole to the power switch and one pole to the fuse, disconnect the polarity switch and any other capacitors that are on the primary side, you can leave the outlet there if you wire it up right. Hook the earth wire to a convenient chassis point, you can either solder it in place, or crimp a circular connector onto it, and hook it to one of the transformer bolts.
If you are worried about RF noise and the like, you might want to fit an IEC jack instead (kettle power cord socket) you can buy them with built in noise suppression.
(http://media.digikey.com/photos/Schaffner%20EMC%20Photos/FN9222-3-07.JPG)
if you have chassis clearance to fit one.
I'm a dumbass, cap in a circle is a neon light, not sure what it's doing wired like that though. Looks like it would be permanently lit, or I'm having a brainfart. :o
The schem should be the same as the 200s, it's the same three knob 60 watt output amp.
I'm worried about taking out the polarity switch, will there be issues if I leave it/add the three prong anyways?
Yes. The polarity switch allows you to connect one side of the line to ground via a cap. If you are getting shocked it could be that cap is already bad.
Wire it up with a 3 wire, without the polarity cap, safety firzt :)
Use the polarity switch as a secret booster or something ???
I'd use it as a disconnect for the negative feedback loop, that would be fun ;D
I'm going to shoot gutshots, and you can circle the cap for me... haha, I'm worried about toasting this one, It's fragile... at least I feel like it is. I don't want to install that kettle power socket, it'd require some holes being drilled that I don't want to. I may eventually sell it, but I want to bring it into the 21st century first... haha.
Also, will regular 60/40 solder do, or do those lines get too hot?
Shouldn't get that hot, certainly not the power lines, even if they run fairly close to the transformer.
It's usually pretty easy, you'll be ending up with less wiring than you started with :)
Got a question for you guys. Buddy of mine snagged an Ampeg 8x10 for free. Downside is it only has 4 functional speakers. He was thinking of making a 4x10 and 1x15 cab out of it being he's got a bunch of lumber and a bunch 15" speakers laying around and always dug the sound of that cab. My question is, what would the impedance of the 15" speaker need to be to acheive 4 ohms? Or are there any alternative wirings you guys would know? Thanks in advance.
Dang, it depends on the age of the cab. The original SVT drivers were 32 ohms each and they were all in parallel for a 4 ohm load. The newer ones use 8 ohm drivers in series / parallel (like a 4x12) for 2 8 ohm loads or a single 4 ohm load.
Either way, my addled mine just realized, it would be best to get an 8 ohm driver :)
So you'd have 8 ohm top, 8 ohm bottom, or 4 ohm total.
Yeah it's an older cab. Only one input on the back 4ohm load. So, 8ohms on the 15"?
Yeah, I had to edit the brainfart. I meant 8 dammit, not 4.
No 8 ohms.
The total cab impedance is 4 ohms, some cabs have it split in two for two 8 ohm loads as well, so you'll have 8 ohms on the top with your 4 10"s and 8 ohms on the bottom with your one 15". Total impedance of those two sections will be 4 ohms.
8.
32-32-32-32 in series is 8 ohms. Id tap a second jack for the 15 so you can run either/or.
Yeah, I caught that brainfart after I hit send, then edited. Not too swift today. Haha.
Yeah, or / and, remember that the 15" either has to be 4 times the power of one of the 10" or half the power of the biggest amplifier you are going to drive the entire cab with. It will be handling half the total power applied to the cab.
You make speaker cables out of rad extension cables, where do you get your quarter inch males? I wanna buy in bulk.
I was cannibalising. I know I saw switchcrafts recently for like $1.25 or $1.75 can't remember where.
Anyone feel up to critiquing a dumb Sunday night half asleep thought.
If I have a 120V to 12V transformer, that is a 10:1 turns ratio.
If I connect the primary of a second identical transformer to the secondary of the first, I should get 1.2V which represents 100:1 turns ratio.
If I do it again, with a third transformer, thats 120mV, 1000:1 turns ratio.
So if i hook an 8 ohm speaker to the secondary of the third, I should see 8000 ohms on the primary of the first, so I've just cobbled an output transformer out of three old wall warts, don't imagine it has much of a power rating though. Wonder if I could drive a 6V6 with it ???
Now I'll use another 120 to 12 and a 120 to 9 (reversed) for the power :)
Quote from: Hemisaurus on May 01, 2011, 11:52:30 PM
Anyone feel up to critiquing a dumb Sunday night half asleep thought.
If I have a 120V to 12V transformer, that is a 10:1 turns ratio.
If I connect the primary of a second identical transformer to the secondary of the first, I should get 1.2V which represents 100:1 turns ratio.
If I do it again, with a third transformer, thats 120mV, 1000:1 turns ratio.
So if i hook an 8 ohm speaker to the secondary of the third, I should see 8000 ohms on the primary of the first, so I've just cobbled an output transformer out of three old wall warts, don't imagine it has much of a power rating though. Wonder if I could drive a 6V6 with it ???
Now I'll use another 120 to 12 and a 120 to 9 (reversed) for the power :)
this sounds interesting to me. surely it would be about a watt or two of output, right?
I don't know. I'm thinking if I have a transformer that does 12V@1A then the primary can handle 120V@100mA, with that as a limitation, that should knock on, so
120V @ 100 mA > 12V@ 1A > BOOM :-\
Working backwards, I can never put anymore than 100 mA into the primary, so I can have on the third transformer secondary 1A, so the primary has 100 mA
The second transformer has 100mA on it's secondary, so that's 10mA on it's primary
The first transformer has 10mA on it's secondary, so 1mA on it's primary, doesn't allow for much power output with a plate current of 1mA tops.
But I think all of the above must be hokum, or at least a lot of it. It's been way too long since I did all this stuff at school.
A question for Hemi:
Is there any reason why you couldn't put switches in the tone stack of a tube amp to switch the caps for different eq/voicing? I could draw a schemetic if that would help.
No reason atall, that's what the Orange FAC control is. Keep the caps close to, or on the switch to save the signal traveling too far.
(http://www.planetoftheamps.com/orangemat-200-007.jpg)
Ah cool Thanks. I knew you would know.
I also didn't know what the FAC switch did, I've only played an Orange once long ago but they rebooted the company.
The FAC on Orange, Depth on Matamp and I think Deep on Electric are just a bunch of caps that can be switched in, either between the input and first gain stage, or first gain stage and the tone stack. I think Dumble and Mesa have different caps that can be switched in or out of the tone stack itself, with various push/pull knobs.
Schematic Heaven is your friend :)
Aha I've been using other sites with schematics, I like Heaven.
Hemi-Sunn0))), I got an easy one for ya. The preamp out (solid state Randall, old'n) is rated at "500 M.V.". I'd like to run that signal through my Acoustic 370 but it doesn't have a power amp in jack. How far off are the values of the preamp signal and what the instrument input can take on the Acoustic? I know on some amps the signal is much too hot for the receiving amp but it worked okay when I tried it befo'. Is it possible that it would sound fine but be hurting something? Ol' Nessie has been in duty since 1974 w/ one service in '96 and I don't wanna fuckle 'er up but if she can take this "500 M.V." like a champ, then 'ey. I got me these two women, see, and they ain't up to snuff alone, put 'em together and the domestic bliss is the order of the day
Wait, it gets more stupiderer. Instrument cable or speaker cable for pre-out power-in? Inst. I reckon...
Edit: Fucked this one all up by accident, original post quoted below
Quote from: Metal Dave on May 27, 2011, 12:35:23 PM
Hemi-Sunn0))), I got an easy one for ya. The preamp out (solid state Randall, old'n) is rated at "500 M.V.". I'd like to run that signal through my Acoustic 370 but it doesn't have a power amp in jack. How far off are the values of the preamp signal and what the instrument input can take on the Acoustic? I know on some amps the signal is much too hot for the receiving amp but it worked okay when I tried it befo'. Is it possible that it would sound fine but be hurting something? Ol' Nessie has been in duty since 1974 w/ one service in '96 and I don't wanna fuckle 'er up but if she can take this "500 M.V." like a champ, then 'ey. I got me these two women, see, and they ain't up to snuff alone, put 'em together and the domestic bliss is the order of the day
Wait, it gets more stupiderer. Instrument cable or speaker cable for pre-out power-in? Inst. I reckon...
500 millivolts is less than what an active bass puts out, and about 5 - 10 times what a passive bass puts out, you should be fine running it, if you keep the input gain low-ish.
And yes, instrument cable :)
Quote from: Metal Dave on May 27, 2011, 01:54:08 PM
But wait, there's more !! I saw the ohms breakdown but there's still fog in my brain. I have two speaker outs, 4 ohm it says, right between the jacks. Here be confusion betwixt my beloved bandmates/brothers, we still have this bone of contention to the point we don't even discuss it anymore. Examples of our disconnect:
a) Amp has two speaker outs, there's one label saying 4 ohms exactly between the two. My buddy says each out goes to its own 8 ohm cab, reason being that only one out at a time is 4, and they're bridged to 8 if both used.. I run one out to one 8, then chain out to another 8. I explained daisy-chaining as best I could, that two strung together cuts the number in half. He says that occurs at the spk outs on the amp. If that's true (and maybe it is?) why mislead a dummy like me with "speaker outs 4 ohms". instead of "Each spkr out is 4 ohms individually, in tandem it is 8 ohm".
Wouldn't they specify "each output 4 ohms alone. If used together each output is 8 ohms"? At any rate I told ol' boy if his way were true, wouldn't it be indicated at the output? By his reasoning, if I chained two 8 cabs in to one out, that'd match one output = 4 ohms. If I do that again, then cab 3 and 4, both 8 ohms, go into the other 4 ohm out
....My brain all hurty, and now there's a shiny thing on the ground I can't quit looking at.
Once on the old forum, there was a rumor that someone was spotted who not only knew Ohm's Law of Resistance, but could explain it so musicians could understand. Bill Curtis is still looking for that guy !
Another one is that across equal wattage amps, four ohms is twice as loud/powerful as eight which is twice as 16. Buncha bunk, right?
OK, your friend is wrong, and your are
almost right.
99% of
solid-state amplifiers have a specified minimum impedance, and you can connect as many speakers as you want down to that minimum impedance, so for a 4 ohm, you can have four 16 ohm cabs (16/4 = 4) or two 8 ohm cabs (8/2 = 4) or one 4 ohm cab (4/1 =4). Most speaker outs are normalled or parallel connected, which means it doesn't matter whether you daisy-chain from one speaker out, or connect one speaker to each speaker out.
A few
solid-state amplifiers have a series connected speaker out, usually you'd see this on a combo amp, and the jack would be marked external (though the word external on a jack is no guarantee it's in series), in this case you can connect as many cabs as you like to that jack, as long as the internal speaker is connected, because in series every cab you connect is added in series, ie you have an 8 ohm internal and you connect an 8 ohm external you've got 16 ohms.
Tube amps are, hang on I think I covered all this in the first post in the thread, go read it. ;D
The 4 is louder than 8 is louder than 16 is true, but only for solid-state amps, and it's not twice as loud, and it's not twice the power. If you have a solid-state amp that delivers 100W into 4 ohms, it'll deliver about 75W into 8 ohms and 50W into 16 ohms, this is not including losses, which would mean the amount of loss an amp has to deliver 100W into 4 ohms, it may deliver nearer 80-90W into 8 ohms and 60-70W into 16 ohms.
Human hearing can't hear changes much less than 3dB, and double the power is 3dB, so basically you can barely hear the difference between a 50W amp and a 100W amp. To get twice as loud you need to have 10 times the power, so 100W amp is half as loud as 1000W amp (assuming the speakers have the same efficiency, which they won't :-X)
Yeah, I was in the ballpark then about the ohms/power thing. So my two 4 ohm spkr outs send a 4 ohm load each, no matter if one, the other, or both are being used, jah ?
Thanks man, reading my coffee-fueled paragraphs had to be a chore
No, you have to have 4 ohms total, one 4 ohm cab to one jack, or one 8 ohm cab each on two jacks, or two 8 ohm cabs on one jack.
A friend of mine is using a Boss Equalizer GE-7. It's got some age to it and when you try to switch it on, doesn't really work and are required to spazz out and stomp it a few times in order for the pedal to stay on. I was able to get into the battery compartment, messed around with the switch (turning it on/off), this seemed to have helped a tiny bit, but still required to spazz out on it. I believe the switch might just be dirty, but still uncertain.
Any ideas/solutions?
Switches you can use the non-lubricating contact cleaner from the hardware store OR the lubricating contact cleaner from radioshack on, just spray it on the little switch, try and get it to drizzle down the shaft and enter the body of the switch, and work the switch a few more times, if you don't have a hardware store, try an auto store for contact cleaner.
If this doesn't work, maybe it's time to replace the switch. In Boss gear it's a momentary microswitch that triggers a buffer, you can replace it with another similarly sized momentary microswitch, or follow one of the many online guides and put in a regular 'true bypass' switch.
If the guy is like my buddy, and leaves the EQ on all the time, it might be easier to hardwire that, let me know. WCS you can do it with a penknife ;)
Quote from: Hemisaurus on May 27, 2011, 04:52:24 PM
No, you have to have 4 ohms total, one 4 ohm cab to one jack, or one 8 ohm cab each on two jacks, or two 8 ohm cabs on one jack.
Man, I'm still trippin', thanks for being patient with me. Lemme restate my confusion for ya, it'll be humorous if nothin else ! The two outs are simply labeled once: "4 Ohms". I totally get how I could chain two 8 ohm cabs together to make one 4 ohm load, and plug into one jack on the amp. Can I not do the same thing with the other jack? Can I not plug one 4 ohm load into one jack, and another 4 load into the other? If I do use only one spkr out w/ a 4 ohm cab, how does that affect (if any) the other jack?
I'm really struggling for a good analogy here, back in school we were taught the plumbing analogy, it can sort of be applied here. Imagine your amp is a hosepipe, the end of the hose is the speaker jack, you can screw a Y adaptor onto the end (or cut a hole in the pipe) it's not going to make the water come out any faster.
Your speaker outs are a Y adaptor, they both connect to the same hose. Your amp can handle 4 ohms total, that's it. If you put 4 ohms on one jack, and 4 ohms on the other jack, that's the same as chaining 4 cabs together, you get 2 ohms, boom, your amp is fried.
That's where the hosepipe analogy breaks down, you split too many hoses off of one hose, things don't blow up, the water pressure just drops. If more things blew up on people, more people might understand ohms law :)
PS If anyone has a good analogy let me know, I seem to be explaining ohms law to someone every other week.
Thanks Hemi!
My friend doesn't ride the pedal all the time, so hardwiring it will be out of the question.
OK, well if cleaning and/or replacing the switch doesn't work, I can explain to you how to fit a regular stomp switch to it, it's just a matter of Q4 and Q5 coming out, and wiring the switch in there.
Deoxit is the easily obtainble cleaner/lubricant. I use this canadian 13 dollar a can cork sniffer contsct cleaner, so im not much help haha.
Thanks man, the Y split clarification was what I was looking for; I see now that it's gotta be 4 ohms, no matter what's plugged into either/or/both jacks. The orig. owners manual probably covered that, but it's not clearly labeled for the average idiot. (me, most people). Some amp mfg's specify what to plug/what not to plug on the back...
Anyway, thanks dude, and yes if more shit was damaged by incorrect use then more people would learn. "I always do it like _____and it's never been a problem!!" is tough to argue with. I've mismatched every which-a way with this particular amp and it still works, wrong as I may have been...
If someone is running a lot of pedals but want to cut the signal loss, would an A/B or A/B/Y pedal do the trick? (e.g fuzz, distortion, overdrive, octave on one side and tremolo, phaser, chorus etc on the other side)
Most ABY pedals are passive, and do not buffer/boost the signal, so they won't help you. I think some Radial ones are buffered. http://www.tonebone.com/tb-loopbone.htm (http://www.tonebone.com/tb-loopbone.htm)
Boss has a pedal as well http://www.bossus.com/gear/productdetails.php?ProductId=150&ParentId=262 (http://www.bossus.com/gear/productdetails.php?ProductId=150&ParentId=262) for buffering effects loops.
Or you can add a booster pedal in at the beginning of the chain (at the end works but will be more noisy)
http://www.pedalspluseffectswarehouse.com/Clean_Boost_s/44.htm (http://www.pedalspluseffectswarehouse.com/Clean_Boost_s/44.htm)
Thanks for the info Hemi!
Master volume question:
I understand the concept of Master volume amps with a separate gain volume and Non-Master volume amps, but what confuses me are Master volume amps with a gain knob, volume knob AND a master volume. Can you explain that one?
Would that be a multi-channel amp?
In tube-land, gain is rarely actual gain, it's generally a volume control before a fixed gain stage, so that you can overdrive, or not overdrive the gain stage with the gain knob and then turn the thing down clean or dirty with the volume knob.
Input > Pink Channel > attenuation > gain stage > attenuation > mixer stage > master volume > power amp section
Gain Channel Vol
If you have a specific unit in mind, you can check out the schematic, or I can ;)
It's a Fender Mustang I amp - been looking for a small practice amp & it looks like fun. It's a single channel amp, but footswitchable between 2 amp model presets (?).
Still gain, volume and master volume has me confused on this one...
Looks like it's like my VAMP, and like PODs and other modelling doofers.
The Gain/Vol/Bass/Treble are under software control, probably rotary encoders, they are feeding parameters to the model. The master volume is an actual pot and controls the level of the modelled signal.
In theory, this allows you to dime all you modelling controls so the modelled amp is running full on, with maximum power tube crunchiness, and then you can turn it down with the master volume, as it's a physical control.
Make sense?
Yeah, I guess. I mean I understand Master volume & gain in tube amps, but with a solid state modeling amp it seems kind of wonky.
It's way easier to get gain on a solid state amp :)
If you imagine the modeled amp as being a small amp in a big box with a window, which is the amp modeller. The small amp has 4 knobs on it, like many amps. Then there's a knob on the big box to control how far you open the window.
Great explanation, thanks!
<crickets>
(http://farm6.static.flickr.com/5178/5509462831_b6a3f0228c.jpg)
HAHAHA TOM'S AMPS!
I'm going to message him on facebook.
Quote from: Slow on June 14, 2011, 09:28:13 PM
Herbie should post the "how to bias" thread now... I'm gonna have to retube it now... engh... son of a bitch.
Any idiot can bias a Concert Lead ;)
I say, as per manufacturer, or failing that, as per the equipment you have to hand.
Does your amp have a bias point, do you have a bias probe, do you have a scope?
http://tone-lizard.com/Biasing.htm (http://tone-lizard.com/Biasing.htm)
if there's no manufacturers bias procedure, and there is an adjustable bias, I'll use a scope.
https://ssl.eurotubes.com/cart/index.php?page=view_products&category_id=108&sub_category_id=109 (https://ssl.eurotubes.com/cart/index.php?page=view_products&category_id=108&sub_category_id=109)
or
https://taweber.powweb.com/store/modkits.htm#BR-Kit (https://taweber.powweb.com/store/modkits.htm#BR-Kit)
or just make yer own.
Swank tits, is it worth the investment? I'll buy my tubes from there, too. I'm kind of sad to see these tubes go :(
The stock JCM800 is fixed bias.. isn't it?
bullllllsshit...
(http://dub.greboguru.org/jcm.png)
PS, Sunn can you cut this end of the thread, and paste it into tech thread?
indeed! so the 800 is fixed bias? that would give me a woody.
oi, thats the bias pot. derp. I can read schematics, I just don't know how to apply it to the physical realm... R35, R36, R37, R38 are my screen resistors?
What you're pointing to is a trimmer, or a pot?
Which leads me to my next question, Do I have to bias each socket, or is that a master, so I can just read one socket and set from there?
If you are buying a bias probe from eurotubes, you might as well follow his instructions too. I solemnly believe there is more than one way to skin a cat, or bias an amp in this case.
http://eurotubes.com/euro-Generic-Bias.htm (http://eurotubes.com/euro-Generic-Bias.htm)
He just happens to use a JCM 800 as his generic amp ;)
It is a trimmer or at least it's a non-front panel adjustment, depends on your model where it is, you got one of those whacky PCB's so I don't know where it will be for you. It would be fairer to call it more of a bias balance as it affects all the tubes at once, you have to check each tube, and use the adjustment to get a happy medium.
Solid, so it doesn't have to be exact?
I understand I can use 6550s in it, but someone told me I had to add something, or change some resistor values somewhere. T/F?
T.
I think you could drop KT-77'S in w/out mods.
Sold. That's what I was going to buy. This is exciting...
A quick question for Hemi or anyone with 4pro experience. Right now I'm running a 1/4 plug from channel A or B output, and was reading that if you have the stereo/mono button in the wrong position you won't get full power. I also read some shit about running mono bridged mode using the speakon connector. Well I got the speakon plug but can't set this thing up till Saturdays show. Is it as easy as a plug from mono/bridged output into 8olm cab? The rear panel on this thing is kinda busy, with a shit ton of config options.
Manual http://www.ampeg.com/pdf/SVT4PRO.pdf (http://www.ampeg.com/pdf/SVT4PRO.pdf)
Page 12 - Note that a speakon cable for the A/B output is not wired the same as a speakon cable for the Mono out. If by plug you mean you bought just the plug, and plan to make your own cable, that's OK. If by plug you mean the whole cable, you may need to double check it.
Also if the Speakon is an NL-2 and not an NL-4, it does not have the required terminals for the Mono Output, which is wired between 1+ and 2+ instead of the standard 1+ 1-, this is the 'bridge mode' standard for most amps.
Quick Table for Speakons
Regular Cable +ve=1+ -ve=1-
Biamp Cable Lo +ve =1+ Lo -ve=1-
Hi +ve =2+ Hi -ve=2-
Bridge Cable +ve=1+ -ve=2+
Why you wanna fuck me all up with equations and shit. What I got was a speakon to 1/4 plug. Now I'll have to see if it's for mono mode. I've read thru that manual a few times, but a lot of it is foreign to me.
Fuck! The one I have is Nl-2 +1. Looks like I'll be at the GC tomorrow. See, this place is beyond useful.
Quote from: bass sic on June 15, 2011, 08:55:57 PM
Why you wanna fuck me all up with equations and shit. What I got was a speakon to 1/4 plug. Now I'll have to see if it's for mono mode. I've read thru that manual a few times, but a lot of it is foreign to me.
Dude, I didn't have time to make it nice and pretty, there's no equations. Just there's 3 major types of Speakon Cable. 1+, 1-, 2+ and 2- are what Neutrik chose to label the terminals.
The standard cable the signal is carried on the 1+ and 1- terminals
(http://dub.greboguru.org/speakon.gif)
The bridged cable the signal is carried on the 1+ and 2+ terminals
(http://dub.greboguru.org/bridge-speakon.gif)
For biamp, the lows are on the 1+ and 1- terminals and the highs on the 2+ and 2- terminals
(http://dub.greboguru.org/speakon-2way.jpg)
OK, one more Dumbass question so I don't fuck this up. Having the proper speakon connector in hand, a +2 -2 do I use regular instrument cable or speaker cable? I ask because the fully assembled one I bought had the biggest cable and biggest 1/4 jack I've ever seen. I plan to hack a inst cable and install the speakon on the end.
Quote from: bass sic on June 16, 2011, 01:32:50 PM
OK, one more Dumbass question so I don't fuck this up. Having the proper speakon connector in hand, a +2 -2 do I use regular instrument cable or speaker cable? I ask because the fully assembled one I bought had the biggest cable and biggest 1/4 jack I've ever seen. I plan to hack a inst cable and install the speakon on the end.
Yeah, you want to use a speaker cable, you don't want to put > 1000W bridged through an instrument cable :)
So hack the end of a speaker cable, it should be pretty simple, those Neutrik's use screw terminals, so you just strip the ends and screw them in, no solder required. Do try and use a fairly hefty 1/4", you'll be carrying a lot of current
Power = Amps ^2 x Resistance
So if you're pushing a 4 ohm cab
1200 = Amps ^2 x 4
Amps ^2 = 1200/4
Amps = SQRT (300)
Amps = 17.3A
Yeah that's math, don't worry about it, just realise your household outlets carry only 15A, so use a nice hefty cable ;)
Sweet. It all makes better sense once I had parts in hand. Done, and thanks for the help.
Herbie - is there any methodology hints and tricks for tracing out a pcb to draw out a schematic?
My Dimarizo Very Metal pedal doesn't seem to have any schematics online so I'd do the world a favour.
Quote from: inductorguitars on June 17, 2011, 05:48:11 PM
Herbie - is there any methodology hints and tricks for tracing out a pcb to draw out a schematic?
My Dimarizo Very Metal pedal doesn't seem to have any schematics online so I'd do the world a favour.
Pick an end and work from it? At least you have the unit in front of you, I'm going to try and trace a Solasound Sustain from a bunch of pics (see amp guts thread) (http://riffrocklives.com/forum/index.php?topic=594.59).
According to this link http://www.freestompboxes.org/viewtopic.php?f=1&t=8713&p=95198&hilit=dimarzio+very+metal#p93103 (http://www.freestompboxes.org/viewtopic.php?f=1&t=8713&p=95198&hilit=dimarzio+very+metal#p93103) it's a RAT, and there are a ton of RAT schematics out there, maybe you can just check that's how it is, and mark one up.
Ah I see. I started tracing/drawing but got lost. The Rat schematics I have saved were the newer ones and look nothing like the Very metal. The older rat's (Rat I?) look like my drawings.
Ok here's one for ya Hemi. My 69 Super Bass is redplating v4 and v5 and blowing the 4 amp Mains fuse.
also when I have channel II volume up around 7 or 8, it wants to feedback like micrphonics. i haven't even opened it up yet. I have several other amps I can use. I'm pretty capable at fixing just about anything. Fixing things is what I do for a living. I know my way around amps a bit having done several repairs already. Curious to see what direction you would take first. Thanks.
Redplating is usually leaky coupling caps in my experience, let me grab a schematic later and look for particular culprits, but whateve cap couples those valves to the previous section.
http://www.webphix.com/schematic%20heaven/www.schematicheaven.com/marshallamps/jcm800_superbass_100w_1992.pdf (http://www.webphix.com/schematic%20heaven/www.schematicheaven.com/marshallamps/jcm800_superbass_100w_1992.pdf)
Check if C17 is passing DC voltage.
Channel II a two channel SuperBass? Microphonics == preamp tube, get a new tube swap out each preamp tube 'til you find the dodgy one, or replace them all.
Oh and you might find once you fix C17, others start going as well, might be time for a full recap.
Well i think you need to change your thought process straight off. This is a 1969 early metal panel Super Bass. Think Plexi. Not a JCM 800 1992. And yes, all 4 holers are 2 channel. (I-2 inputs,II-2 inputs) just not switchable. I know you know this ;).
But I think you're prolly right about the coupling cap. that's my first inclination.
Well if I can't see a schematic labelled Super Bass that's not a 1992, show me a schematic and I can give you a better answer ;)
The reason I was asking on the two channel ones, where it's two volumes and a common tone stack, the jacks feed two separate tube stages, I can't recall whether it's two parts of the same 12AX7 or two different 12AX7's, and then they are mixed for the tone stack. Anyhoo, if the microphony is only on channel 2, then the tube that's unique to that stage is the one with problems.
Like I said though, seriously consider a more thorough recap, I fixed a bad coupling cap on one of my amps, and a few hours later it started redplating somewhere else, so do keep an eye on it.
Actually it's STILL called a 1992, thanks for being consistent Marshall.
(http://drtube.com/schematics/marshall/1992u.gif)
(http://drtube.com/schematics/marshall/1992.gif)
and the two channels are two parts of the same 12AX7, so it's probably V1 that is bad.
and my comment on the coupling cap holds, the one that feeds both V4 and V5 (the two that are redplating), the .1, thanks Unicord for not labelling any of the components, bet your parts lists were a barrel of laughs. :o
Have you ever noticed how some schematics are just much easier to read than others? Despite being split into two sections, the Marshall, to me, is clearer than the Unicord, Peavey is one of the worst offenders of unintelligible schematics, because they draw the schematics separated into boards.
hey hemi, i have a relatively simple (i hope) question:
how do you figure how where to set pickup height? is it a personal preference? i got my guitar back from the tech last week, but he jacked w/ the pickup height and now it doesn't seem like my amp is as loud . . . should i just crank that bastard back up? or does he know something i don't??? :P
It's a matter of preference. The further the pickup from the strings = the less output. All of my bridge pickups are pretty damn close to the strings, as I enjoy maximum output. You just have to play with the height until you get the bridge/neck at an even output, and go from there, whether you want more or less output, raise/lower accordingly.
Quote from: SunnO))) on June 20, 2011, 10:22:16 AM
It's a matter of preference. The further the pickup from the strings = the less output. All of my bridge pickups are pretty damn close to the strings, as I enjoy maximum output. You just have to play with the height until you get the bridge/neck at an even output, and go from there, whether you want more or less output, raise/lower accordingly.
right on. man, i thought something was wrong with my amp . . . i'll mess with that over the course of the next week or so. luckily we don't have any shows/practices scheduled so i can get all my shizz in order before the next one.
<rant>
I'm borrowing an Ampeg B-15n portaflex '63. First I thought the grill was rattling, now I'm not so sure. It sounds more like a torn speaker, but only on high volume settings. I even taped up the handle, since it hangs in the cab.
I'm thinking one of three things
1) power tubes are shot
2) a bad solder joint in the power section
3) needs a recone or new speaker
I'll be testing with a different cab soon...
Any other suggestions?
Well I can't hear it, so it's hard to tell ;)
I think the new cab will probably help, I'm always finding loosened mountings on speakers, rattling baffle boards, and that kind of thing. A few cabs have had an arsenal of extra hardware added to keep them rock solid.
Don't sit the amp on the cab if you can help it.
Quote from: Hemisaurus on June 28, 2011, 09:04:43 PM
Don't sit the amp on the cab if you can help it.
can't help it it's a fliptop. :D
I figured it out after a bunch of experimenting. The handle is vibrating side to side instead of back and forth when I taped it up.
It still has the Original Ampeg tubes made by Sylvania. Still sounds good but a retube is probably in order soon.
Even the fliptops you should be able to release the catches and lift it off.
Quote from: Hemisaurus on June 28, 2011, 09:37:47 PM
Even the fliptops you should be able to release the catches and lift it off.
Yep but I'd have to seal it off somehow. (Don't really want to go scrouning for plywood)
It's not like the fliptop makes it airtight, if you're worried a piece of scrap wood on top and a couple of phonebooks holding it down would have much the same effect ;D
Or turn the cab upside down, let the floor do the work.
Sigh, 10.66 ohms, 6x10 cab, run amp at 8 or 16? Sunn 610L with Celestions sounds like shiitttt. Dunno why, either.
6 16 ohm speakers. sigh sigh sigh sigh
fucking annoying. I don't want to sell this cab, but I hate this cab.
Quote from: SunnO))) on July 07, 2011, 03:51:13 PM
Sigh, 10.66 ohms, 6x10 cab, run amp at 8 or 16? Sunn 610L with Celestions sounds like shiitttt. Dunno why, either.
6 16 ohm speakers. sigh sigh sigh sigh
fucking annoying. I don't want to sell this cab, but I hate this cab.
8. i think it is too far away from 16 but close enough to 8.
it sounds like shit? really?
Most 16 ohm cabs ive metered run 12-15 ohms. Sound city says 16 ohm tap. Herb says?
I'd have personally said the 8 ohm tap, tube amp go low, solid state go high, but if Sound City say the 16, use the 16.
You could stick two 8 ohm drivers in the cab, and make it 8 ohm u'know ;)
Quote from: Hemisaurus on July 07, 2011, 05:25:49 PM
I'd have personally said the 8 ohm tap, tube amp go low, solid state go high, but if Sound City say the 16, use the 16.
You could stick two 8 ohm drivers in the cab, and make it 8 ohm u'know ;)
i bet you could fit two 18s in there, right?!
http://www.soundcitysite.com/sc_webpages/6x10_cab_wiring.pdf (http://www.soundcitysite.com/sc_webpages/6x10_cab_wiring.pdf)
Should I trust it?
Are you pushing it with a Sound City amp?
Justin, I should have been clearer, if he replaces two of the 16 ohm drivers with 8 ohm drivers, wires the four 16's series-parallel like a 4x12, for 16 ohm. Then wire the two 8 ohm drivers in series for another 16 ohms, wire those two sets in parallel for 8 ohm.
Or get another cab that can be rewired for 32 ohm, and add it on for an 8 ohm load
Nope... v4.
You would want to run the amp at sixteen ohms. It is better to have the speakers lower impedance than what the amp is looking for.
From my understanding, V4s are bitchy about impedance mismatches though so be careful. I know my buddy destroyed his V4 w/ a mismatch, like cheaper to buy another amp destroyed... but is was a really bad mismatch due to some dead speakers in his cab.
Yeah, I'd fake it, disconnect one pair of speakers and make it 16 for now, it's not worth the heartache of a blown transformer.
Should I recap when I retube? Where can I dig up the caps?
Do I have to measure each tube when I bias with that bastard probe, or should I just measure off the pins and do the math?
How long do they have to burn in before I play 'em?
Quote from: Hemisaurus on June 15, 2011, 11:36:31 AM
If you are buying a bias probe from eurotubes, you might as well follow his instructions too. I solemnly believe there is more than one way to skin a cat, or bias an amp in this case.
http://eurotubes.com/euro-Generic-Bias.htm (http://eurotubes.com/euro-Generic-Bias.htm)
He just happens to use a JCM 800 as his generic amp ;)
It is a trimmer or at least it's a non-front panel adjustment, depends on your model where it is, you got one of those whacky PCB's so I don't know where it will be for you. It would be fairer to call it more of a bias balance as it affects all the tubes at once, you have to check each tube, and use the adjustment to get a happy medium.
and no you don't need to recap when you retube, how old is the amp and when was it last retubed?
You don't have to let new tubes burn in, but they may change tone after you play them a while. Some people advise bringing a recapped amp up on a variac, I don't know if thats strictly necessary with todays capacitors.
Quote from: Hemisaurus on July 09, 2011, 09:09:44 AM
and no you don't need to recap when you retube, how old is the amp and when was it last retubed?
You don't have to let new tubes burn in, but they may change tone after you play them a while. Some people advise bringing a recapped amp up on a variac, I don't know if thats strictly necessary with todays capacitors.
i always thought you did that in case the new caps threw something else out of spec (can't remember what) so you don't blow your tranny? (unless you are in to that sort of thing!!)
86, and im assuming never. Its only seen heavy use this passed year...
Yeah sorry, I meant how long since it was recapp'd not retubed :)
It might be an idea to give it a cap job, if it hasn't ever had one. Even with no use, old caps can dry out, some of it is just old age, heavy use or no.
Recapping can bring up the voltage, so it is necessary to rebias after a recap, but not necessary to retube, unless those tubes are old, and the new voltage makes them fail. That's not too likely a scenario, as most amps don't run tubes half as hard as they are spec'd.
So what I'm saying is.
- You don't have to recap when you retube.
- You don't have to retube when you recap
- You do have to rebias, when you recap or retube
I have a little 10 watt tube practice amp that just suddenly started making a horrendously loud buzzing sound. The amp still passes signal but the buzz is always louder than what I'm playing. Tried different cables and guitars (nothing else in the signal path) and there is no difference.
Take it to a tech.
Not knowing the amp, or how it is built, or how old it is, you could be looking at broken tubes, dried out caps, lifted ground, shorted wires, shorted caps, or whatever.
OR
http://www.diyguitarist.com/Misc/J_Darr.htm (http://www.diyguitarist.com/Misc/J_Darr.htm)
Chopstick poke test...
Good for dodgy solder joints not much else. A fault that bad shouldn't take muchbench time.
I have a question for the people with the knowledge!
I am running 2 full stacks. One stack is Mesa Boogie Rectifier loaded with V30's. They are 8 ohm cabs.
The other stack is Matamp loaded with Celestion G12T-100's. These are 16 ohm cabs.
When I run my GT120 through the Mesa it is fuck-all loud, real nice and in your face.
When I run the same GT through the Matamp cabs, it is loud, but not nearly as loud as the Mesa.
Any ideas about what is going on here? I'm not sure how the cabs are wired inside. I don't want to sell my Matamp cabs, but I need them to be as loud as the Mesa's.
HELP!! :o
Assuming your remember to change the impedance on your amp correctly for each set of cabs. It would be the sensitivity of the speakers 100dB on the V30's vs. 97dB on the G12T-100's
If you aren't remembering to change the impedance it's because your about to melt the output transformer ;D
No I remembered to change the impedance. Do you really think that 3 db would be THAT noticeable?
So it wouldn't really matter how it is wired inside?
I don't know shit about this stuff man, thanks for your help.
Quote from: core9 on July 14, 2011, 01:44:47 PM
No I remembered to change the impedance. Do you really think that 3 db would be THAT noticeable?
So it wouldn't really matter how it is wired inside?
I don't know shit about this stuff man, thanks for your help.
The 3dB is for 1W at 1meter usually, not that it's a linear thing, but across 8 speakers it's going to be significant, anyways the frequency responses are going to be different too, some are more bassy, some more middy, some just plain sound louder.
Thanks bro!
Dumb Fact A tube amp is fractionally louder on it's highest impedance setting, because the higher the cab impedance, the less significant the losses in the cables are.
Example If you have a 4 ohm cab, and your cable has a 1 ohm loss, 20% of your signal is lost in the cable. If you have a 16 ohm cab and a 1 ohm cable loss, 5.9% (1/17th) of your signal is lost in the cable.
Marshall originally adopted 16 ohm (or 15 ohm) as it's standard setting because people were using long runs of 18 gauge wire for speaker cables.
So if your cab is 4 / 16 ohm switchable, and your amp has 4 and 16 ohm taps (switch settings or whatever) go with the higher value.
NB always match the tube amp with the cab impedance, running a 16 ohm cab on an 8 ohm tap is NOT a good idea!
hemi,
I think i'm going to re-wire all my cabs to 16 ohms now!
also, i have a question about cutting a new baffle:
i have an old peavey PA cab that had 2x12 in a tuned enclosure. no speakers in it. i'm going to cut a new baffle to put my two 15s in there (it will fit) but i don't know how to put the baffle in. do i just screw it in from the sides and then caulk around the inside to make it air tight? do i cut a port? i am the lost . . .
You do it however best you can do it. The main thing is to get it air tight, and make sure the baffle doesn't buzz.
I imagine one way to do it, that will probably mean you don't have to marr the tolex on the outside would be to install a, and here my knowledge of woodworking fails me, trim or whatever a piece of wood running all the way round the inside of the cab, making a lip that the front baffle would rest on, always use screws AND wood glue on cabs, the screws keep it tighter than nails, and the glue keeps it airtight and prevents the screws backing out.
Now I think Sunn as constructor, may have more valuable info ??? Here's some tips from two really good sites on speaker construction in general.
http://speakerplans.com/index.php?id=guide (http://speakerplans.com/index.php?id=guide)
http://www.dancetech.com/construction.cfm (http://www.dancetech.com/construction.cfm)
nice, right on!
now what kind of wood should i use for the baffle?
Use 3/4' birch plywood. You have to set in new cleats behind the baffle, since you'll destroy the old ones getting the old baffle out. Just use 1x1's, cut them into the correct dimensions, recess them deep enough for the baffle, and the grill. glue and screw.
Super Dense MDF. Or marine birch plywood, but for a baffle MDF would be a little less air-gappy. Observe proper precautions when cutting MDF :o
Dusty from Knife of Simpson did something like this to his 2x15, see if I can find a pic
Fuck MDF. Worthless bullshit.
Quote from: Hemisaurus on July 15, 2011, 11:18:44 AM
Super Dense MDF. Or marine birch plywood, but for a baffle MDF would be a little less air-gappy. Observe proper precautions when cutting MDF :o
Dusty from Knife of Simpson did something like this to his 2x15, see if I can find a pic
what are the proper precautions? i'm assuming it involves not injuring yourself since it is so dense?
MDF is sawdust and glue. It's just shitty. I'll never use it on anything.
Oh here we go again, Mr Mastercraftsman. ;)
Acoustically speaking MDF is superior to birch plywood, as it is absolutely void free, but it suffers from the fact it's susceptible to water, if you plan to get it very wet, you will damage the MDF, a couple of soakings in the rain won't hurt it, submerging it in a flooded trunk will.
Birch however is more durable and weatherproof, and almost as void free (if you get the good stuff, Marine Birch) as MDF.
You see a lot of manufacturers make a shell of birch, and a baffle of MDF. You were replacing a baffle hence I suggested MDF above birch, that, and to watch Sunn's blood pressure soar ;D
MDF is nasty stuff when you cut it, so the safety precautions are wear a mask when cutting and drilling it. You don't want to inhale it.
Just out of interest, what are you loading it with, and what will be the box volume once you finish?
-shakes fist- DAMN KIDS!
It's susceptible to any form of moisture... It'll soften up in a heartbeat, just sayin', player.
The precautions I use when I use MDF... oh wait, I don't, because it's a gigantic sheet of BULLSHIT. ^.^
Quote from: Hemisaurus on July 15, 2011, 11:32:15 AM
Just out of interest, what are you loading it with, and what will be the box volume once you finish?
a set of 15" ev forces. as for the volume, since i don't have the cab, i can't measure it . . . i need to get that fingered out, huh?
Quote from: justinhedrick on July 15, 2011, 12:00:48 PM
Quote from: Hemisaurus on July 15, 2011, 11:32:15 AM
Just out of interest, what are you loading it with, and what will be the box volume once you finish?
a set of 15" ev forces. as for the volume, since i don't have the cab, i can't measure it . . . i need to get that fingered out, huh?
If you know the model number, you may be able to check out the dimensions http://peavey.com/support/searchmanuals/archived.cfm (http://peavey.com/support/searchmanuals/archived.cfm)
You may find you end up porting the box, ported boxes generally need smaller volumes than closed box.
Quote from: SunnO))) on July 15, 2011, 11:51:39 AM
-shakes fist- DAMN KIDS!
It's susceptible to any form of moisture... It'll soften up in a heartbeat, just sayin', player.
The precautions I use when I use MDF... oh wait, I don't, because it's a gigantic sheet of BULLSHIT. ^.^
This from the man who insists any Behringer pedal is going to explode as soon as he nudges it with his big toe ;)
MDF is going to hold up better than the pressed cardboard that Peavey seem to use for front baffles, when I get the time, and the skills (or borrow the skills from someone) I'll make an MDF bass that will blow your Mahogany bullshit out the water ;)
PS Keep taking the tablets, whenever you feel a twinge.
Cornholer.
ok. i'm probably going to buy MDF. sorry sunn.
Hmm, after hunting about came up with the EV datasheet, and what do you know, unlike Eminence who give recommended box dimensions, EV does not :(
Modelling it for optimum, it needs a massive box, because of it's high Q, but it will go low if the box is big enough, dimensions are in liters.
(http://dub.greboguru.org/boxy.jpg)
645 liters = 22.77796 cubic feet
1289 liters = 45.5206054 cubic feet
However this is optimum, any idea what the box is, we can plug in the values and see.
Is all this just falling in your lap? It might be better to get some 12's for the box otherwise, if bass is a thing you need.
Quote from: Hemisaurus on July 15, 2011, 03:50:20 PM
Hmm, after hunting about came up with the EV datasheet, and what do you know, unlike Eminence who give recommended box dimensions, EV does not :(
Modelling it for optimum, it needs a massive box, because of it's high Q, but it will go low if the box is big enough, dimensions are in liters.
(http://dub.greboguru.org/boxy.jpg)
645 liters = 22.77796 cubic feet
1289 liters = 45.5206054 cubic feet
However this is optimum, any idea what the box is, we can plug in the values and see.
Is all this just falling in your lap? It might be better to get some 12's for the box otherwise, if bass is a thing you need.
yes, i have the 15s already, i have the box. i need a smaller 2x15 than the kustom one i already have. boom.
Is it for guitar or bass?
Say we took a typical enclosure very small as it originally house 12"'s 32" x 17" x 12" basically a box with just enough space to fit the drivers and not too deep, that's gonna get you 180 liters, if you'll forgive my metricness.
In this case by the box is so small there's no difference between a sealed box, and a vented box, if you tune the vent flat, and even if you don't there's not much extra to gain
(http://dub.greboguru.org/boxy2.jpg)
For guitar this might rip, as it will be right in the punch range, even bass might sound OK, as long as it was a more rock bass and a less sub/dub/sunn bass. You're gonna need a VERY big box for those speakers if you want <80Hz
Suck it and see you might like it. Is the front baffle already off the box, as in is it already useless?
Quote from: Hemisaurus on July 15, 2011, 03:59:11 PM
Is it for guitar or bass?
Say we took a typical enclosure very small as it originally house 12"'s 32" x 17" x 12" basically a box with just enough space to fit the drivers and not too deep, that's gonna get you 180 liters, if you'll forgive my metricness.
In this case by the box is so small there's no difference between a sealed box, and a vented box, if you tune the vent flat, and even if you don't there's not much extra to gain
(http://dub.greboguru.org/boxy2.jpg)
For guitar this might rip, as it will be right in the punch range, even bass might sound OK, as long as it was a more rock bass and a less sub/dub/sunn bass. You're gonna need a VERY big box for those speakers if you want <80Hz
Suck it and see you might like it. Is the front baffle already off the box, as in is it already useless?
it's for guitar. the front baffle is NOT uses, but it is liek this: the top half of the cabinet as the baffle for the speakers, the bottom half has the scoop or whatever you'd call it for bass frequencies, so all of that would come out, and i'd just make a straight baffle for it.
What's the model # of the speakers, or even the range? Too many Peavey's to guess at.
If we're assuming that 32 x 17 x 12 box (180 liters) that's almost perfect for a ported pair of Eminence Delta 12" only -3dB at 50Hz
(http://dub.greboguru.org/boxy3.jpg)
Quote from: Hemisaurus on July 15, 2011, 04:16:15 PM
What's the model # of the speakers, or even the range? Too many Peavey's to guess at.
If we're assuming that 32 x 17 x 12 box (180 liters) that's almost perfect for a ported pair of Eminence Delta 12" only -3dB at 50Hz
(http://dub.greboguru.org/boxy3.jpg)
i don't have it in front of me. been trying to track it down on the webs . . . can't find it.
i am going to be using 15s because i already have them hemi, i'm not buying 12s.
Of course if you wanted MORE bass from what you have you can overtune the port for a giant peak, be 3 dB down @ 50Hz over 0dB between 60-200Hz, and only use one of your drivers.
(http://dub.greboguru.org/boxy4.jpg)
Course if the cab is bigger than my guesstimate and nearer 360 liters you can do this with both drivers.
I had figured you could trade he 15's for 12's ;)
Quote from: Hemisaurus on July 15, 2011, 04:26:44 PM
Of course if you wanted MORE bass from what you have you can overtune the port for a giant peak, be 3 dB down @ 50Hz over 0dB between 60-200Hz, and only use one of your drivers.
(http://dub.greboguru.org/boxy4.jpg)
Course if the cab is bigger than my guesstimate and nearer 360 liters you can do this with both drivers.
I had figured you could trade he 15's for 12's ;)
do you have any 12s? is that what you're saying?
No.
Sigh. I'm buying a Musicman HD-130 head thats going to need a recap and retube.
Looks like it's time to get confident.
Really confident, and you'll need some really good EL34's. 725V on the plate means much owchie ;)
6CA7's were standard, originally, in the earlier ones, eh?
Pasted from Eurotubes:
E34L
Factory description: Gold plated control grid for improved fidelity. Special plate alloy improves plate dissipation as compared to the standard EL34 resulting in stable performance at higher power levels.
Our observation: This tube has about 20% more head room than the standard EL34 and it also has a deeper, tighter low end. The E34L is also a bit punchier and more aggressive than the standard EL34 which makes it a Great tube for Matchless, Bogner, Carvin, Peavey and all Marshall amps. I have them in one of my old SUNN heads. Incredible sound! The E34L and the JJ KT77 are the only EL34 type tubes that I have found that will stand up to the 700 plus plate volts found in the Musicman HD 130 amps.
So I should stick KT77's in 'er? That's fine with me...
So he says, the different impedance would be something I'd think about, but if he's done it.
Mine came with a set o GT 6CA7's and I never had to retube it.
That's what I'm saying... he sells big bottle 6CA7's, and they're cheaper than the 77's, and they're the tubes that should be in that amp...
So use the E34L? The above said E34L or KT77, and the E34L is cheaper than the KT or the 6CA7.
and in answer to your original question, no, they spec'd EL34 or 6CA7's for that, back in the day when men were men, and tubes were tubes :)
I tune down to A and play a lot of heavy doomy chugging type riffs into my Laney GH50 with the gain all the way up into a 2x12 cab that has Eminence Governor 75 watt speakers. When I turn the amp way up(like way louder than practice volume) the speakers distort a great deal. If I was to swap the Governors for some higher wattage speakers, say in the neighborhood of 125 or 150 watts would I be able to turn up really loud without getting a lot of speaker distortion? How bad is speaker distortion for speakers? How do you tell whether you are hearing speaker distortion or tube distortion? The thing is that with my old 4x12 with Eminence Manowar 125 watt speakers there wasn't any excessive distortion at super loud volumes, just super super loud sound. I got the 2x12 because I wanted a lighter cab and I also wanted something with some warmer/darker sounding speakers, Manowars are pretty bright sounding. I don't think Eminence makes any higher wattage handling 12" speakers that aren't bright, I'm not sure who does.
Right now I don't really need speakers that can handle my amp on 7 or 8, we haven't started playing out live yet and even when we do I'm not sure how often we would want that kind of volume but I'd like to be able to do it and do it right if it's needed. But if that sounds crazy please tell me so. I've never been in a band that actually gigged and have no idea what it's like to be running through a PA and have stage monitors running various signals and what not.
edit: I'm thinking that some 15" Big Bens would probably do the trick but I really don't even have money for new speakers let alone a new cab or 2 new cabs.
This is definitely one of those wish it was here moments. Speakers can distort in a lot of ways, but unfortunately so can speaker cabinets. Baffles can rattle, jack panels can buzz, speakers can be loosely mounted, even handles can rattle.
Have someone play your guitar, or feed a walkman or ipod into the fx loop of your amp, and get it to distort, and try feeling your way round the amp, does pressing on anything cure the distortion? Try the joints, the handles, the jack panel, the rear panels, front panels, and check the screws holding in your speakers are tight. Do they screw into wood or does it use t-nuts, etc.
The obvious answer, if it's not the cab would be to pull 2 speakers from your 4x12 and swap them in, you can use your tone knob if they sound too bright, then you'll have a 250W 2x12 and still handle 300W safely on your 4x12, so tell us about the impedances ;)
I'll check to make sure the cab and speakers are tight and solid but I've only had the thing a few months. I sold the 4x12 so I don't have those Manowars anymore. I did mess with the tone knobs and what not but it seems like a bright speaker is still a bright speaker in the end.
I really don't think a 2x12 can sound as heavy as a 4x12 but you shave 20 lbs with 2 less speakers plus there is usually less wood. That 4x12 was quite wide and a bitch to lug up and down stairs by myself, my shoulders are pretty weak.
Is the 2x12 closed or open back? Fully closed cabs are going to sound bassier, open back cabs waste bass.
I've heard a Marshall 1x12 sound as heavy as a 4x12, so it's not cab size.
MDF VS Birch ply
It's a trade off. Yes MDF is more dense, but it's heavy as fuck. DUH. Any moisture will degrade it. Eventually it will rot. I have a cabinet in my kitchen that is rotting away from the humidity.
The Birch ply is void free, lighter, and won't rot.
I'm with Sunn use the birch ply.
Quote from: Hemisaurus on July 19, 2011, 07:51:09 AM
Is the 2x12 closed or open back? Fully closed cabs are going to sound bassier, open back cabs waste bass.
I've heard a Marshall 1x12 sound as heavy as a 4x12, so it's not cab size.
I just think 4 speakers sound heavier than 1 or 2, generally. I'm doing pretty well with 2 plus the 15" bass combo for now though.
Quote from: inductorguitars on July 19, 2011, 11:51:30 AM
MDF VS Birch ply
It's a trade off. Yes MDF is more dense, but it's heavy as fuck. DUH. Any moisture will degrade it. Eventually it will rot. I have a cabinet in my kitchen that is rotting away from the humidity.
The Birch ply is void free, lighter, and won't rot.
I'm with Sunn use the birch ply.
That explains why those cheap-ass MDF cabs I picked up in 1989, and had brought all the way from Scotland
by sea are totally
not falling apart ;D
Well they're only 22 years old, and on their third set of woofers ::)
Quote from: Hemisaurus on July 20, 2011, 12:30:37 AM
Quote from: inductorguitars on July 19, 2011, 11:51:30 AM
MDF VS Birch ply
It's a trade off. Yes MDF is more dense, but it's heavy as fuck. DUH. Any moisture will degrade it. Eventually it will rot. I have a cabinet in my kitchen that is rotting away from the humidity.
The Birch ply is void free, lighter, and won't rot.
I'm with Sunn use the birch ply.
That explains why those cheap-ass MDF cabs I picked up in 1989, and had brought all the way from Scotland by sea are totally not falling apart ;D
Well they're only 22 years old, and on their third set of woofers ::)
Ireland****
Pedal question!
Have a late 90's Deluxe Memory Man reissue with the old 3 prong AC cord. Last night I decided to jam in my bedroom and plugged my Epiphone Valve and DMM into the same outlet and got a loud hum. Even after giving them separate outlets, the hum continued. Went back into the living room and plugged into an outlet and no hum at all, even with the amp and the pedal sharing the same outlet.
What gives?
Sounds like you have either a bad ground in your bedroom, or something electrically noisy on that circuit.
Get yourself an outlet tester, and check your bedroom, I once rented a place where half the grounds hadn't actually been grounded, which was brought to my attention when I got a shock from my cable box.
(http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_214.jpg) (http://x0.no/24jg)
Quote from: Hemisaurus on July 20, 2011, 10:17:20 AM
Sounds like you have either a bad ground in your bedroom, or something electrically noisy on that circuit.
Get yourself an outlet tester, and check your bedroom, I once rented a place where half the grounds hadn't actually been grounded, which was brought to my attention when I got a shock from my cable box.
(http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_214.jpg) (http://www.harborfreight.com/electric-receptacle-tester-32906.html)
i rented a place for a summer that wasn't grounded either. the whole house wasn't. i was always worried about grabbing the door handle of the fridge with wet hands . . . not to mention the ungodly hum from all of my gear. a buddy of mine let me use this outlet box that was ancient that had 2 extension cords that plugged into the outlets, then 4 plugins. but there was a 3rd extension cord that you ran to a rod that he pounded into the ground. worked well, but i was always scared aobut using it.
Hey Sunn. See the above pictures are actually links.
For some reason the forum is chopping off the last character, or maybe it's this crazy iPad, check it ???
Yep, it appears to be the crazy iPad >:(
Yeah, they're fine.
Alright, opened up my HD-130, to make a list of what I'm going to need in terms of caps. The tubes are solid. You've confirmed that it should be hyper-fuckin' loud. Anyways, I was reading on the MM site that I should replace... every cap in the amp, at this point... What do you say, Herbie? Is that just a load of shit? Also, the big ol' silver can caps, and the slightly smaller but still large blue caps don't have the farad value on them? Does that matter, as long as I replace them with the same MFD/voltage rating... is that the farad rating? Gotta learn somehow...
I know I won't be able to get Mallory replacements, anymore, so where do I source 'em, I tried googling/Mouser, but to no avail because I don't actually know what I'm looking for.
When I do the physical job, is it acceptable to clip the leads from the old caps, and solder the new leads to the old leads, so I don't have to lift the board, or is that half-assing it? I'm trying to save manhandling the boards too much, they're pretty brittle after all those years.
Soon as I get back from the airport, I'll post some pics. I'm having trouble figuring out which is the bias pot, one of them is the trem adjustment, I know that much. The schems online are kind of hard to make out, The chassis number is 2475-130 UL
Also, if you can find me a printed copy of that Jack Darr book under 60 bucks, ill buy it...
Weber has the caps I need, Axial electrolytic caps?
(http://i1234.photobucket.com/albums/ff409/enslavedinrot/2011-07-23_16-43-21_577.jpg)
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MFD is microfarads. In the power supply, the voltage rating is critical, more critical than a precise Farad rating, it's OK if you put bigger caps in the power supply farad wise, as long as they meet or exceed the voltage rating of the circuit.
I'm saying before you go ripping it to shreds, you can try and figure out if it is the caps, it could be the speakers in the combo, or it could be a bad connection, mine got real quiet when I brought it home, turned out I'd knocked something and the B+ had dropped to half what it should be, hence me saying check the B+.
If you have a solid B+, measured DC of > 700V and there's no AC voltage on your B+ line, say less than 10V AC depending on your meter, that means that the B+ is solid, and the caps on it are doing a good job of controlling the AC ripple. Then find the Bias point as mentioned on the schematic, and set it like it says. Some chicken-hearted tech may have bias'd the amp real cold because he was scared of blowing the tubes.
You can cut the leads of an old cap, but I'd only suggest doing that as a repair method if you were replacing a couple of caps, and don't want to rip it apart, and I would also want to put silicon caulk under the new cap as it won't have a lot of mechanical strength, and they can be physically quite big.
Some people say recap the amp, get it done, some people say don't touch it, it sounded great, just fix it. One of the best stories I heard was here http://www.amp-fix.com/amps.htm (http://www.amp-fix.com/amps.htm) read the bit about the 59 Bassman, belonging to a certain person. I love that story, because it shows a tech working hard, and locating and fixing the problems, rather than just throwing a whole bunch of new parts at it.
My suspicion would be the amp may be pretty solid, and just underbias'd, but obviously that's an internet hunch, as I haven't laid eyes, ears or voltmeter on it. So does it have the 12AX7?
I did the simple shit already, different cabs without the combo at all. It does have the 12ax7. Dumb it down a scad for me, B+? I follow most of this well, im just unfamiliar with the shorthand. The schem I found for it won't load on my computer for some reason. Check the voltage at pin 3, on any socket? 700+ = good to go? Less = replace caps?
700+ and little AC good
600+ and a lot of AC bad caps
450 or less, probably a bad joint somewhere.
B+ is either the plate voltage OR the voltage applied to the center tap of the output transformer, they get interchanged, but the value will be similar ;D
As to the Darr book, long out of print, take the PDF to Kinko's and make a spiral bound version, good for the bench.
Yes Axial caps. Radials are the ones that stand up. Get the right working voltage though, meet or exceed the previous one.
See, I catch on quick. I don't have to measure at the tranny, but I can if needed? Pin 3 on any tube socket, load applied, standby off? Checking DCV on the same pin as I'm checking ACV, correct?
If the voltage is low, not much AC involved, the bias pot will adjust the B+, then be measured in mA by my socket probe deal I just ordered, too?
Just ordered the full KT77 retube kit for my Marshall, too, so I'll probably be fiddling around here looking for more answers. Off to find the full PDF of that book. I need it, I thirst for knowledge and shitter reading material.
Thanks, Herb, you know I'll be here groping you for more advice. I might as well learn all of this shit before I go to school for it, so I can breeze it...
http://www.diyguitarist.com/Misc/J_Darr.htm (http://www.diyguitarist.com/Misc/J_Darr.htm) is as good as it gets, that's the first two sections of the book. Section 3 was a pile of schematics, which was handy in the days before the internet, not so necessary now.
You'd only be checking the output transformer voltage if you thought something was wrong with it.
You're a bit off on the statement below.
Pin 3 is the plate voltage, you want a good steady DC level of > 700V and very little AC, the AC is residual ripple on top of the DC level after the capacitors have done their filtering / smoothing work, the Darr book explains it.
The B+ is not adjustable, it is what it is, it may drop a little as you adjust the bias, but only because of the demand placed on it by the tubes.
The bias adjusts a negative voltage that is applied to the grid of the tube, it's like setting the idle in a car, your engine doesn't start from 0 rpm, nor does your tube start from off.
The socket probe is measuring the idle current of your amp, the current that flows from the plate (anode) to the ground (cathode) when no signal is applied. I suggest in this instance, you do the manufacturers procedure, which does not require a probe.
(http://www.music-in.de/pics/hd130b.gif) (http://www.music-in.de/pics/hd130b.gif)
Click on it to make it bigger.
Yes, load applied, ie. speaker connected else things go boom.
Yes standby off, or amp fully on if your prefer, in standby the plate voltages are switched off, and only the heater voltage is applied to the tubes.
Off on vacation, so don't take offense if I don't respond to any posts for a few weeks ;)
Quote from: Hemisaurus on July 18, 2011, 08:46:33 AM
This is definitely one of those wish it was here moments. Speakers can distort in a lot of ways, but unfortunately so can speaker cabinets. Baffles can rattle, jack panels can buzz, speakers can be loosely mounted, even handles can rattle.
Have someone play your guitar, or feed a walkman or ipod into the fx loop of your amp, and get it to distort, and try feeling your way round the amp, does pressing on anything cure the distortion? Try the joints, the handles, the jack panel, the rear panels, front panels, and check the screws holding in your speakers are tight. Do they screw into wood or does it use t-nuts, etc.
The obvious answer, if it's not the cab would be to pull 2 speakers from your 4x12 and swap them in, you can use your tone knob if they sound too bright, then you'll have a 250W 2x12 and still handle 300W safely on your 4x12, so tell us about the impedances ;)
I just played through a 15" bass cab and got the same speaker distortion at high volume levels, actually I can start to hear it at around 2 on my Laney which is minimum practice volume. It's not quite as fuzzy sounding because the tone of the bass cab is darker but it still happens big time. I'm thinking it has to be the elusive and mystical power amp tube break up I always read about, only I wasn't on a quest to find it. But is it possible that my tubes are just about shot and need to be replaced? Or is a 50 watt amp just inferior to a 100 watt amp for trying to dial in more of a regular heavy metal high gain sound at high volume levels? Is tube break up hard on the tubes or amp itself?
Is this in different spots, a lot of rooms have their own resonant items, drywall rattles, lightswitch panels buzz, ducts vibrate etc. I have the advantage where I can drag stuff out into the open air, and the only bouncing I get is off the barn across the yard.
If you're tubes are shot, you won't get me describing it, like Zappa said, it would be like dancing about architecture.
Tube breakup is hard on tubes, as you are running them full on, it's like running your cars engine at maximum revs, it's gonna hurt it, even if you are only in first gear and going 30 mph, it's also hard on the amp, as the rest of it works hard to support the tubes.
If you want a heavy metal sound, and you don't want tube worries, Randall and Peavey both do some very nice solid state heads.
50W to 100W is 3dB I think, I believe a mouse may fart louder than that ;)
This is the sort of problem you'd definitely be better getting a local expert in on, someone that can actually hear what is going on. Failing that experiment yourself, different cabs, different locations, different tubes, different amps.
If you hear the same rattle with two different heads on the same cab, it's not the head.
If you hear the same rattle on two different cabs with the same head it's not the cab.
But if you drag that suspect cab/head to a different spot, and it sounds different or better, you've been chasing phantoms, I spent a while doing this with one of my cabs, tightening down the driver, going round the cab looking for squeaks, finally realised I was just vibrating the ducting on my furnace :-[
Herbis, If I wanted to hop into speaker reconing, Is it any more complicated than replacing the cone, and voice coil? Magnets don't go bad, oi?
Quote from: Hemisaurus on August 03, 2011, 10:53:58 PM
Is this in different spots, a lot of rooms have their own resonant items, drywall rattles, lightswitch panels buzz, ducts vibrate etc. I have the advantage where I can drag stuff out into the open air, and the only bouncing I get is off the barn across the yard.
If you're tubes are shot, you won't get me describing it, like Zappa said, it would be like dancing about architecture.
Tube breakup is hard on tubes, as you are running them full on, it's like running your cars engine at maximum revs, it's gonna hurt it, even if you are only in first gear and going 30 mph, it's also hard on the amp, as the rest of it works hard to support the tubes.
If you want a heavy metal sound, and you don't want tube worries, Randall and Peavey both do some very nice solid state heads.
50W to 100W is 3dB I think, I believe a mouse may fart louder than that ;)
This is the sort of problem you'd definitely be better getting a local expert in on, someone that can actually hear what is going on. Failing that experiment yourself, different cabs, different locations, different tubes, different amps.
If you hear the same rattle with two different heads on the same cab, it's not the head.
If you hear the same rattle on two different cabs with the same head it's not the cab.
But if you drag that suspect cab/head to a different spot, and it sounds different or better, you've been chasing phantoms, I spent a while doing this with one of my cabs, tightening down the driver, going round the cab looking for squeaks, finally realised I was just vibrating the ducting on my furnace :-[
This was the second cab in the same room. This is distortion coming out of the speakers for sure, both cabs, not anything in the room vibrating. I can't see how it's not the head at this point. I'll take the head in and have them check into it. Thanks for the info.
Quote from: SunnO))) on August 03, 2011, 11:03:25 PM
Herbis, If I wanted to hop into speaker reconing, Is it any more complicated than replacing the cone, and voice coil? Magnets don't go bad, oi?
They can age, and get slightly weaker, but no, not bad.
Tryin' to learn.
Biased my Marshall, turned out great. I wanna do that bright cap mod, but it's not where It's supposed to be, according to all the pictures. Everything I have is board mount, including the pots, no caps connected to the preamp... shit, I guess I could follow the trace to the wiper of the preamp pot, and that would be my bright cap, oi? ??? ??? ???
Haven't touched the MM yet, that comes ASAP, though...
Quote from: SunnO))) on August 04, 2011, 01:43:11 PM
Tryin' to learn.
Biased my Marshall, turned out great. I wanna do that bright cap mod, but it's not where It's supposed to be, according to all the pictures. Everything I have is board mount, including the pots, no caps connected to the preamp... shit, I guess I could follow the trace to the wiper of the preamp pot, and that would be my bright cap, oi? ??? ??? ???
Haven't touched the MM yet, that comes ASAP, though...
Doncha mean
AZAP!!Seriously 725V may jump a bit, be wary.
Dunno, you know I don't know those PCB mounted JCM800's, Marshall used to be pretty good about making things pretty clear, so yeah if the circuit is identical, and the bright cap is on the track of a pot. What do you mean bright cap? JCM800s don't have a bright switch, are you talking about futzing with some of the coupling caps for more bass?
Long as your careful taking the part out, and replace it with a cap of equal or better voltage capability, the worst that should happen is it makes bad noise, just make sure and save the old part ;)
There's a cap that if you just snip one leg out, and bend it away, it'll cut the brightness of the amp (which it is, almost unbearably so.) It can be done on every 2203/2204/etc... Danny G, and Worthless Willie did it to theirs, and said it made a world of difference.
http://www.tdpri.com/forum/amp-central-station/13035-jcm800-bright-cap-mod-success.html (http://www.tdpri.com/forum/amp-central-station/13035-jcm800-bright-cap-mod-success.html)
What you mean you don't run it with the vol on 10 all the time ;)
Yeah trace the circuit, look for a 1nF cap, looking at the 2203 schematic, there's only one 1nF cap on it, so should be easy to narrow down. Of course there's a thing on your guitar called, err, a tone control ;D
It doesnt effect the master. Which is usually 7+, only the pre, which is on about 5. 4-6 is where the mod is supposed to shine. So, It needs to be done.y
Quote from: SunnO))) on August 05, 2011, 04:46:50 PM
It doesnt effect the master. Which is usually 7+, only the pre, which is on about 5. 4-6 is where the mod is supposed to shine. So, It needs to be done.y
do it. do it. a buddy of mine has 2 800s that has 1 w/o the cap and 1 with. night and day difference. for realz. both are PC board amps too.
For shits and giggles you should ground the cap at the wiper end, after disconnecting it from the wiper first of course.
Then you have a LF boost instead ;D
Quote from: Hemisaurus on August 03, 2011, 10:53:58 PMIf you want a heavy metal sound, and you don't want tube worries, Randall and Peavey both do some very nice solid state heads.
Just took my Laney into the shop today. Most heavy metal guitarists who prefer a high gain sound use tube amps it seems but if the amp guy says there isn't anything wrong with my head and I am able to determine that I wasn't experiencing speaker breakup I will look into getting a solid state head, it just needs to not sound like static crap. I like a dark smooth high gain sound, not brittle and trashy and super trebly.
Hemi & Sunno}}}
Avoid shit like this?
http://www.ebay.com/itm/Sovtek-Mig-60-Chassis-/250875965587?pt=LH_DefaultDomain_0&hash=item3a695f7093#ht_500wt_1136
Not necessarily, well, yes, at that price, but if you just need parts, I buy cooked amps all the time. The caps look brand new, and I can't see anything burned in the picture. Probably a fuse, or something dumb... or a dead PT. Either way, not worth 200 bucks.
You need parts?
No.
Just buy curious.
People are asking 650+ for Sovteks on the 'bay.
If you're looking to buy it for yourself, I'd probably pass. too many variables with a sight unseen amp.
I'd do the math, and see if it still sounds worth it.
Retube kit (using Eurotubes for a 50W Marshall as a guide) $61
New Power Tranny (Magnetic Components again using 50W Marshall) $82
New Output Tranny (same as above) $53
So you're talking the buying price, plus the $40 shipping, plus $61 for a new set of tubes, so an extra $100 to start.
If one or both of the trannies are bad, add that on.
If you can't do your own repairs, figure tech bench fees probably a $40 minimum if you're lucky, more likely $80 minimum and another however much $40-80 per hour.
You can get a Bugera for $300-$350 new, with tubes, that works, and is 100W, you can pop out two of the tubes to make it like the 60, Freightshakin' Bob runs his with two tubes, and I have a story about that for another time, but it sounds good, he's happy. I remember the Peavey Windsor used to knock about for $399 as well, again 100W again with tubes, again works out the box.
It's scarey but these are both budget tube amps, which really is what the Sovtek is too, except they are new and come with warranty. I can't fathom people paying a fortune for dodgy knock-offs, when you can get new knock-offs for cheaper???
Quote from: Jor el on August 19, 2011, 11:58:17 AM
No.
Just buy curious.
People are asking 650+ for Sovteks on the 'bay.
jesus, i feel bad about selling mine for $250 about 3 months ago . . .
Which of those Bugeras ended up on your bench because it couldn't handle the heat? I've had several people ask me to replace those molex plugs that just melt to the board...
That was the other Bugera, the Peavey clone, he sold that and got the Plexi clone. Probably has the same connector though ;D
The backstory is he fucked up on the impedance calculation and played it for maybe 3 months or more of gigs and 4 hour weekly practices with the impedance switch twice as high as it should have been, he pulled two tubes, and should have set it to 4 ohm for his 8 ohm cab, instead he set it to 16 ohm.
Damn me if it didn't take it, not that I ever recommend the impedance mismatch to anyone ever, but I was impressed that it took it, Bob is not a quiet player, they built him a little plexiglass screen like a drum screen to go round his amp.
Okay, got my Laney GH50 back from the shop, they said nothing is wrong with it. Took it in because when I crank my Epi Les Paul Junior Special(Super Distortion pup, tuned down to G# currently) through it(no distortion pedals) with both gain knobs all the way up(I play heavy metal) into my 16 ohm 2x12 with Eminence Governor 75 watt speakers I get tons of extra breakup/distortion, like mega crazy Weedeater sounding but more shitty tone. I start noticing this around 2 but it gets really bad past 4 or 5, at 7 or 8 it's complete shit, not that I need to play that loud. Power chords played starting on the C# string aren't AS bad but that G# really makes it breakup.
Just this morning I plugged into my band mate's 2 15" bass cabs. I messed around for awhile at low volume and then cranked it to 3 or 4 and immediately the amp sounded like I had it on 1 and like complete shit! ????? I played for a moment like this and then tried turning it back up, nothing. Stuck my nose near the top amp vent and it smelled pretty normal I guess, there is a hot odor but I think that is normal.
Immediately I then plug it into my 2x12 guitar cab and it sounded normal, not good, still the break up past 2 or so but normal.
The 15s are 8 ohm cabs and I had one line going from the amp to each using the 2x8 outputs. Thinking I may have fucked it up somehow though..?
I just checked the 2x12 and all of the speakers are screwed in tight, all of the wood is tight.
Thinking this issue is mainly related to the extra bass that tuning down to G#(I was in A, same deal) produces but I'd really like to know if I'm hearing pre or power amp breakup or speaker breakup or both.
I'm going to try to get my buddy over Saturday with one of his high gain amps(Mesa, Peavey) and his 2x12(which I think is 16 ohms) to do some comparing.
The shop I just had my amp at has a solid state Randall for $100 but I'm not sure what model it is..
You're not anywhere near me are you?
I can't imagine a guitar would overpower an amp that quickly with bass, I mean I can swamp a 100W tube head with my bass and it sounds kinda farty on the low B and E, I mean maybe you are overbassing it, have you tried rolling off the bass a little and seeing if it cleans up?
Are you running pedals in front of it atall? If you have access to your bandmates cabs, do you have access to his amps, have you tried your cabs with his amp?
Do you have the kind of tech you can take the whole shooting match in, and play it to him, and say this is what I'm talking about.
Try the amp in kind of a standard setup, E tuned guitar, your 2x12, no pedals, controls all pointing to 12 o'clock (except master volume, and leave the Drive off), see how it sounds, on the internet I can't tell whether your overpowering your amp with signal and EQ, and the amp just can't handle it, or whether there is somthing actually wrong with the amp. If the amp sounds fine with a regular tuned guitar and starts crapping out when you use a downtuned guitar, you maybe need a different amp. That said I've heard C# tuned guitar through a Laney AOR 50 into a Fender 2x15 and it would take your face off.
Maybe you just need to back off the gain a little, full on is not a necessity even for heavy metal, don't believe the spinal tap hype, back off the gain and see if you can find a sound you like, perhaps you just need to ease up on it, Laney's can get kind of ferocious, especially if you put high gain preamp tubes in them.
So, ease up on it, or take the full rig to the tech and show him what you're doing are my two suggestions.
Post a video, bitch!
Push all the boost knobs in.
Quote from: Hemisaurus on August 25, 2011, 03:04:07 PM
You're not anywhere near me are you?
I can't imagine a guitar would overpower an amp that quickly with bass, I mean I can swamp a 100W tube head with my bass and it sounds kinda farty on the low B and E, I mean maybe you are overbassing it, have you tried rolling off the bass a little and seeing if it cleans up?
Are you running pedals in front of it atall? If you have access to your bandmates cabs, do you have access to his amps, have you tried your cabs with his amp?
Do you have the kind of tech you can take the whole shooting match in, and play it to him, and say this is what I'm talking about.
Try the amp in kind of a standard setup, E tuned guitar, your 2x12, no pedals, controls all pointing to 12 o'clock (except master volume, and leave the Drive off), see how it sounds, on the internet I can't tell whether your overpowering your amp with signal and EQ, and the amp just can't handle it, or whether there is somthing actually wrong with the amp. If the amp sounds fine with a regular tuned guitar and starts crapping out when you use a downtuned guitar, you maybe need a different amp. That said I've heard C# tuned guitar through a Laney AOR 50 into a Fender 2x15 and it would take your face off.
Maybe you just need to back off the gain a little, full on is not a necessity even for heavy metal, don't believe the spinal tap hype, back off the gain and see if you can find a sound you like, perhaps you just need to ease up on it, Laney's can get kind of ferocious, especially if you put high gain preamp tubes in them.
So, ease up on it, or take the full rig to the tech and show him what you're doing are my two suggestions.
I'm in Madison, WI.
I only go through my ab box, my wah(which is off most of the time) and my pedalboard before the signal goes to my Laney. The stuff I'm playing now is very much heavy metal, not stoner or sludge. When I say heavy metal I'm talking about Celtic Frost, Manowar, Candlemass, etc but more high gain than the classic albums by those bands and tuned way way lower.
Okay so yesterday my friend let me borrow his Peavey 5150 which is 100 or 120 watts and his 2x12 cab which has 100 watt speakers, my 2x12 has 75 watters. The 5150 is more or less like a 2 channel version of my Laney GH accept double the power. With the gain up all the way on either channel I found I could nearly replicate the sound of my GH with it's gain knobs all the way up. But anyway, first I tried each amp with each cab just to kind of loosely compare them although this was kind of guess work and frustrating so I then used my band mate's 15" bass cabs, each amp on top of a cab side by side running just through my AB box. What I found was that the GH would break up first and that was with the gain all the way up, mostly off(neither amp can produce pure clean tons at even a moderate volume) or half way. I attribute this to the difference in power although it's possible that the character of each amp had some effect. Now I finally believe the people that say a 100 watt amp will give you more clean headroom(or high gain mega distortion head room!) and I would like to add that this is in fact important even with high gain metal amps. You'll be sounding perfect at 1&1/2 or 2 on your main volume knob and from there your tone starts changing the louder you crank. I did play my SG which is tuned in standard E and has stock Gibson humbuckers through each amp and it did not produce as much excessive breakup/distortion as my currently G down tuned Epi with it's single Super Distortion pup. The Epi of course has much thicker strings and puts out more low end.
I also noticed that the 200 watt 2x12 didn't break up as much as the 150 watt 2x12 but the difference in amps was even more of a factor.
I could take the rig into the guitar shop I go to for service and say "hear that? I don't want that" and I'm pretty sure they would(being old dudes into old rock and blues and what not as far as I know) probably tell me I should have a more powerful amp or a solid state amp, higher wattage handling speakers and more speakers. They would probably also tell me that my whole rig sounds like shit even at low volumes and that I tune way too low, hehe.
The Laney GH amps do not have those pull out knobs that allow you to get mega bass tones like the AOR I used to have, that thing was thunderous but i could do the same thing now with an EQ pedal although I have my bass amp for crazy low frequency tones.
I did try backing off the gain and I still heard a lot of breakup but just less metal devastation. I need full on high gain metal madness so the palm muted parts sound heavy enough. Bass speakers are pretty cool sounding but don't allow enough mids and highs through for the sound I want from a guitar amp. Right now I'm thinking I need to check into high gain solid state heads, there are no tubes to breakup so my assumption is that they should provide a lot more headroom but I may need 200 watts or more because they don't seem to provide as much volume per watt than tube amps. My 100 watt solid state Fender bass combo doesn't sound that much more loud on 10 than it does on 4. Also thinking that a couple of cabs loaded with 15" guitar speakers would work wonders although I am only aware of the one model that Eminence makes and I'm not sure how appropriate they are for metal.
Anyone have any recommendations for high gain solid state amps and/or 15" guitar speakers or 12" guitar speakers that can handle 100 watts or more and don't sound too bright? My last cab had Eminence 120 watt Manowars but they were pretty bright sounding.
not sure if you mentioned this previously, but do you use any boost pedals?
Quote from: bitter end on August 29, 2011, 12:49:37 AM
not sure if you mentioned this previously, but do you use any boost pedals?
No, well not for metal anyway. The thing is, the amp's cranked overdrive sound is great for fuzzy turn the air into cottage cheese heavy rock but not so great for the type of heavy metal sound I go for.
If you're in Madison WI, take it to the Guitar Shop, up on Atwood, and make sure you speak to Greg (Ginter) and explain to him exactly what is happening. That guy knows his amps, I've been known to spend several hours just talking amps with the guy. Take your amp, and your cab, take your friends amp too if you want.
Early breakup is both a product of amp design, and tube choice, could be you could get closer to what you want with some different tubes, or could be you'd be better getting a new amp.
Quote from: Hemisaurus on August 29, 2011, 08:56:23 AM
If you're in Madison WI, take it to the Guitar Shop, up on Atwood, and make sure you speak to Greg (Ginter) and explain to him exactly what is happening. That guy knows his amps, I've been known to spend several hours just talking amps with the guy. Take your amp, and your cab, take your friends amp too if you want.
Early breakup is both a product of amp design, and tube choice, could be you could get closer to what you want with some different tubes, or could be you'd be better getting a new amp.
Where do you live?
That's where I took my amp last week. He said there was nothing wrong with it. I'm not sure how much money I want to spend trying to make my Laney sound different if it wasn't really designed to sound the way I want it to sound, you know? If I could get a used solid state amp that would hit the spot for $100-200 I'd rather do that.
Miles away in Central IL. I met Greg when I was at a show at the bar a few doors down from his place, every time I'm in Madison I look him up. I've bought amps from him, nice guy.
Quote from: Hemisaurus on August 29, 2011, 03:51:23 PM
Miles away in Central IL. I met Greg when I was at a show at the bar a few doors down from his place, every time I'm in Madison I look him up. I've bought amps from him, nice guy.
Cool. What show were you at? There are a few bars in that area. Yeah he's always been nice to me when I've been in there and they do good work and usually have a zillion amps for sale. He's got a Randall in there for $100 but I don't know which model it is. He told me he mainly plays solid state amps at home when I mentioned that I was thinking of going that route.
Well unless he's changed his policy, he'll let you demo that amp to your hearts content. Go try it out.
Quote from: Hemisaurus on August 30, 2011, 08:51:32 AM
Well unless he's changed his policy, he'll let you demo that amp to your hearts content. Go try it out.
Tomorrow or Friday for sure. If it runs good super loud but doesn't have good sounding distortion I might just buy it and run it on clean with a pedal.
The Randall at Greg's is actually a Century 200 II which is I think somewhat rare and supposedly doesn't sound near as good as the regular Century which Dime used. Of course I don't care what Dime used at all. I still might go back there and play it for the hell of it.
So I have a minor problem with my T40, the volume knob from 1 of the pups doesn't stick, it just keeps turning without changing the volume. Am I being a moron and what am I missing so that I can fix this?
Thanks
It's likely one of two things.
1. The knob is loose on the pot shaft
If this is the case, is there a little hole on the side of the knob you can fit an allen wrench (hexagonal key) into and tighten the knob up. Or is the knob a press to fit? If it's a press to fit, you could try putting some kind of gunk, like say caulk into the knob to hold it better on the shaft, without gluing it on there permanently, but best would be to get a new knob.
2. The pot itself is spinning around and around.
If this is the case, the volume is following the knob exactly, and as it spins around from 10 to 0 it goes from full loud to dead quiet. In this case the pot is broken, get a new pot. Any of the dozen or so online stores will sell, and likely so will your local music shop. It's likely a 500K, but you can find out for sure when you get the pickguard off, and read the value on the side of the pot.
Thanks, it was the first option. Great bass.
Dear Bowtie Killer,
How's prison?
Why does my Boss FZ-2 drain a 9-volt in a matter of seconds? short? Hot lead grounding out somewhere? HERB?
Have you taken it out the case yet? Are you exaggerating about the seconds part? Does it still seem to function?
If it has a dead short, my first suspect would be the 100uF cap they have across the power rails, if there's not some physical reason like a deformed case, or something inside with the circuitry.
Havent touched it. I metered a 9v before I put it in. 9.1v, after letting it play for about 12 seconds, the LED dimmed, took it out and remetered at 7.9v.
Sent from my DROIDX using Tapatalk
works fine with an adapter, by the way. Ill pop 'er open and find the schem for ya.
Sent from my DROIDX using Tapatalk
(http://experimentalistsanonymous.com/diy/Schematics/Fuzz%20and%20Fuzzy%20Noisemakers/BOSS%20FZ-2.jpg)
Already have the schema, since before I bought my SF-300 ;D
That's odd though, there's nothing really in the circuit between the battery and the jack. Unless the switch on the power jack itself is shorting out, so that when you remove the power jack the battery drains through it.
What kind of draw (current) is it taking from the wall wart?
Do I read that from the wall wart or the pedal? I need a "where to test" lesson... :D
Unless you have a current loop, current testing is done inline, you have to break in to the power line (from the power supply, not the wall) and run it into the current terminal on your meter, and then out via the ground.
Here's a thought, to save you butchering a power supply or something.
Get a couple of old 9v batteries, tear them apart to get the clip on top, solder the clips together like a jumper lead, opposite contacts to each other, snip one of those leads, and you now can measure the current from the battery without tearing things apart.
Could I use one of those One spot battery replacer clips, and measure the positive by poking my probe through the vinyl? Or is that just measuring from the wall? I need to get a book on this. On the schem, that 100uF cap you're talking aboot is right off the DC-in, right off Q11? I'm going to replace the battery snap in the pedal, it never did this before I changed the battery last night. I think I may have been a little rough on'er...
No. You have to interrupt the circuit to measure current, it has to flow through the meter.
You know you can get a battery clip by ripping apart a battery, right ;)
Don't bother measuring the current if you think you just have a duff clip, actually you could take the battery (and power supply) off the pedal, and just ohm out across the clip and see if you read a short.
Will report back with findings! and a new Peavey 8x10!
I had to borrow one of them when I blew my top cab on tour. I was surprised by how little power they can actually handle, like 400W or something?
Be careful.
I noticed that. It's 4 ohms, my 2x15 is 4 ohms, it's got 1200 watts of handling.
between the two, my 650@2 won't kill it, will it? It's 480@4, but I've never turned it passed noon...
Oh that's OK then, the 810TVX is 400W RMS 800W Peak ;D
So it'll handle up to 600? it's getting 450lulz... It's got a blown tweeter. You can dial it out completely on the back, but I may want to replace it for shits and giggles... Peavey sells replacements?
(http://i1234.photobucket.com/albums/ff409/enslavedinrot/2011-09-13_19-36-16_738-2.jpg)
Pretty bass rig, ain't it?
Well it looks like an 810TVX and they are puny as a wet paper towel.
My 4x10 handles 800W RMS and I still managed to blow it, hence my fear of using the 810TVX, I think our last couple of shows on that tour I was kinda quiet. Now I'm using a 500W RMS amp rather than a 3000W amp, and no 4x10's in fact no bloody 10's atall. Only a certified butt-pussy uses 10's ;)
Yeah, but I'm not going to fry it with that 450@4 not really cranked at all, I don't think. I really like how it sounds, it's kind of awesome. If I feel like it's going to give me shit, I'll buy those blowout 10s from Avatar. If I can do it, It'd be 1600 watts of handling. I could run my poweramp at 1200 with it and a 2x15... mmmm....
I wonder if that's just a shitty little tweeter in there... I wonder if it's worth replacing it.
Someone was doing an awesome deal on 15" Fanes, maybe loudspeakersplus.com ???
After my old Selmer amp, with it's 12" Fane, I worship those speakers.
Holy fuck, A grand new? I paid a hundred bucks... I guess it has a crossover in there, too.
Who would pay $1000 for a 400W 8x10 I'd buy a couple of Behringers, and fuck what people say about them.
Those Basson's were nasty cab's. With an 8x10 you get cheap generic 10's and still come out at 800W RMS or more. Parts Express cheapest pro woofer is 125W and $17.94 $144 gets you 1000W handling.
Those are car audio drivers in those Bassons. I've gutted one or two in my day.
The low handling power doesn't worry me, and the speakers sound pretty goddamn good. You're just a weenie when it comes to power. I ran the bass rig with the 8x10/2x15 from my poweramp to see if it matched my volume on guitar just a little while ago. It's louder than me, now, It's nice to not have to dime the preamp and poweramp to get decent volume for once. I'm pleased.
Besides, for a hundred bucks, what the fuck ever, That's a hell of a deal, snobby grumpy Scotsman aside! :D
Hey, just cause you don't own any amps that can blow the balls off it ;D
I think next time out, we need a separate trailer just for speakers. I'll setup a show in Daytona Beach, open your windows, you'll hear it ;D
Quote from: Hemisaurus on September 13, 2011, 10:29:53 PM
Hey, just cause you don't own any amps that can blow the balls off it ;D
I think next time out, we need a separate trailer just for speakers. I'll setup a show in Daytona Beach, open your windows, you'll hear it ;D
Hahaha, I'd come see ya. I'm thinking about a small trailer for our shit, Got plenty of places to store a trailer. They can be had for not too much money 'round these parts.
I had a hitch fitted to the wagon, before the guitarist pussed out and we became a duo.
Don't have the wagon anymore, I've been convincing Gzus he needs to borrow some hard drum cases, and we can put the drums on a roof rack. Bob has a trailer, but it's huge, wouldn't want to pull it with a car.
That EV of mine would be a neat bike trailer, but not 65+mph trailer.
Gearing up for another tour when you become unemployed? ;D ;D
Gearing up for another tour after a couple of years of failed guitarists ;)
Fuck 'em, I guess the gas mask is coming out of retirement.
Quote from: Hemisaurus on September 13, 2011, 10:56:48 PM
Gearing up for another tour after a couple of years of failed guitarists ;)
Fuck 'em, I guess the gas mask is coming out of retirement.
Seriously? EVERYONE has failed you again? Goddamn...
It's a maybe. An ad just appeared on a local forum, that reads pretty much like the one I found our current one from, minus the stuff that made me approach him in the first place. He did play with Gzus for the first time last practice, before that we'd just been figuring shit out between us.
If I wanted to raise the handling power of that cab, Could I, In theory, buy four of those 200W handling Celestions from Avatar, and couple each one with one of the original drivers?
200+50? Or will the 50 watter still blow? I remember there was some rule for this.
Quote from: SunnO))) on September 14, 2011, 10:54:12 PM
If I wanted to raise the handling power of that cab, Could I, In theory, buy four of those 200W handling Celestions from Avatar, and couple each one with one of the original drivers?
200+50? Or will the 50 watter still blow? I remember there was some rule for this.
the chain is only as good as it's weakest link. you will blow the 50s.
I don't want to replace all 8, goddamn it. >:( >:( >:( >:(
You can, but you have to fuck with the impedances.
Imagine that the cab is 4 ohm, the drivers are probably wired up like 2 4x12's (or 4x10's, whatever) or some combination, where you have 4 in parallel (for 2 ohms) in series with another 4 in parallel (for 2+2 ohms), or 4 lots of 2 in series ((8+8)/4), what you need to do is have the bigger drivers be either 16 ohm or 4 ohm if you have a 16 ohm in series with an 8 ohm, it gets twice the power, and your cab is now 16+8/4 or 6 ohms, stuff like that. Or do really lop-sided stuff like put the 4 original all in series for 32 ohms, and then have 4 new 8 ohm in series parallel for 8 ohm, so you have 6.4 ohms. Or just bi-amp the cab, the bottom will be the old drivers present an 8 ohm load and handle 200W, the top will be the new drivers, present an 8 ohm load and handle 800W.
Sunn's used to handle 6 ohm loads because of their 6x12's and 6x10's I don't know if the Model T will handle it or not, maybe it was the 2000S that was meant to do it, if you were using solid state it wouldn't be such a problem. Does the T have a slave out?
Do the T into the top part of the 8x10 with the old drivers @ 150W, and slave a power amp into the bottom part that can handle 800.
There's other stuff you can do to keep the impedance even, like wiring it as a 6x10, having the high powers be 4 ohms, and making it two new drivers in series at 8 ohms, in parallel with 4 old drivers in series/parallel @ 8 ohm, the 4 old drivers are what 50's so they can handle 200W in total, and the new drivers will also be able to handle only 200W so you haven't gained anything.
Figure it out, do some math, do a lot of math ;)
The rules, 8 ohm in series with 4 ohm, 8 ohm gets double the power of the 4
8 ohms in parallel with 4 ohm, 4 ohm gets double the power of the 8
You couldn't have explained it better.
Adding the extra jack, for the biamp, and completely removing the crossover would be more what I want to do... That way I can end up with 8+8=4 when I run both outs. The 200W cab section won't see the full wattage of the 450W poweramp, it's evenly distributed?
I'll just be easy on it, to save money.
OK, can do the power handling, but you're going to have a 10 ohm cab.
50W 8 ohm drivers, all in parallel = 2 ohms
200W 8 ohm drivers in series parallel = 8 ohms
connect the two sets in series = 10 ohms
The 2 ohm section can handle 4*50W = 200W (2 ohms / 10 ohms total) =20%
The 8 ohm section can handle 4x200W = 800W (8 ohms / 10 ohms total) =80%
As you can see the percentage and the power matches, 80% of the power goes to the 200W drivers and 20% to the 50W drivers.
You can safely drive 1000W into your cab, if you can match your amp to 10 ohms.
Does a tube amp run hotter and/or harder on the tubes, transformers, etc at 4 ohms vs 8 or 16? I'm talking 4 ohm output to 4 ohm cab vs 8 or 16 ohm output to 8 or 16 ohm cab of course, not running things wrong.
No. A tube amp, if the impedance switch is set, delivers the same amount of power regardless.
The higher impedance setting (16 ohm) will deliver a negligible amount of extra power, due to the cable losses being minimised (read explanation earlier in this thread).
Quote from: Hemisaurus on September 26, 2011, 07:52:10 AM
No. A tube amp, if the impedance switch is set, delivers the same amount of power regardless.
The higher impedance setting (16 ohm) will deliver a negligible amount of extra power, due to the cable losses being minimised (read explanation earlier in this thread).
Ah thanks. I'll probably make my new cab an 8 ohm then. If I need a second in the future I'll be running 4 ohms which is more power for solid state amps. The only thing is that I'm not sure all tube amps run 4 ohms but I don't have one now that doesn't, just thinking ahead.
All of mine do! ;D ;D The T does 2, as well.
Quote from: liquidsmoke on September 26, 2011, 11:12:28 PM
Quote from: Hemisaurus on September 26, 2011, 07:52:10 AM
No. A tube amp, if the impedance switch is set, delivers the same amount of power regardless.
The higher impedance setting (16 ohm) will deliver a negligible amount of extra power, due to the cable losses being minimised (read explanation earlier in this thread).
Ah thanks. I'll probably make my new cab an 8 ohm then. If I need a second in the future I'll be running 4 ohms which is more power for solid state amps. The only thing is that I'm not sure all tube amps run 4 ohms but I don't have one now that doesn't, just thinking ahead.
you'll need the hemisaurus speaker looper, which allows speaker cabs to be chained in series and parallel ;D
new low price.
Regarding my sunn concert lead head and problems it was having which were solved by this little fix I learned. I figured this handy bit of info would fit into this thread...
I've got a '76 red faced model. It was having some issues with low output and a generally unstable signal. I took it into the local repair guy. He told me that a common problem on these is a corroded contact on a switched jack in the back of the amp. It's the preamp in jack, I believe. The amp isn't in front of me at the moment, but it's either that one or the power amp jack. They are both right next to each other on the back panel.
Take the amp out of the sleeve (4 screws on top) and check that jack. You can see that it's got 3 terminals and a little switch where the contacts are always made unless you plug something into that jack, which causes the contacts to break. Those contacts were oxidized on my amp. I sanded them until they were shiny and now the amp works great. Problem solved. You plug into the front of the amp, right? but I guess the guitar signal comes in and goes through this switch at some point. I hope my description makes sense. If you're having any issues with this amp, I suggest cleaning this switch and see if that solves them. I would assume that some other solid state sunn amps in the concert series, and possibly others will also have a similar signal routing and switched jack.
sounds fair, I've got this exact same problem on my T-Max.
2 quick n' dirty fixes are:
1. Spray contact cleaner in the jack socket, work it in and out with a jack plug
2. Run a patch cord between the pre out and the power in, very handy if it starts crapping out during a show
^had this happen to my cabinet, It wasn't working and then some contact cleaner later its running fine.
I have some tube amp woes right now.
My mesa nomad seemed to lack power the other night. Admittedly the tubes are probably 3 years old, and have had 100's of hours of high volume play on them. I am assuming its just power tubes starting to die yeah?
I pulled out my Butcher and plugged it in. I stopped using it because it just wasnt loud enough. though I have been doing some reading, and they are supposed to be wicked loud. My nomad was a lot louder, and did have a tone I liked so I just switched back.
I havent fired up the Butcher in quite some time. It was super hissy, and noisy. Extremely so actually. However the volume was great. It had lots of balls and sounded killer, but the hiss and noise when my volume knob was down was so loud I couldnt talk over it. I am assuming this is a microphonic pre amp tube. (Relatively new tubes, with little use) As the night went on though, the volume and punch started to drop in the amp as well.
Anyone have a clue? I dont want to run out and buy 300+ dollars is tubes if I dont need to.
Quote from: rayinreverse on October 04, 2011, 01:10:19 PM
I have some tube amp woes right now.
My mesa nomad seemed to lack power the other night. Admittedly the tubes are probably 3 years old, and have had 100's of hours of high volume play on them. I am assuming its just power tubes starting to die yeah?
I pulled out my Butcher and plugged it in. I stopped using it because it just wasnt loud enough. though I have been doing some reading, and they are supposed to be wicked loud. My nomad was a lot louder, and did have a tone I liked so I just switched back.
I havent fired up the Butcher in quite some time. It was super hissy, and noisy. Extremely so actually. However the volume was great. It had lots of balls and sounded killer, but the hiss and noise when my volume knob was down was so loud I couldnt talk over it. I am assuming this is a microphonic pre amp tube. (Relatively new tubes, with little use) As the night went on though, the volume and punch started to drop in the amp as well.
Anyone have a clue? I dont want to run out and buy 300+ dollars is tubes if I dont need to.
could be:
bad tubes
bad caps
dirty pots/jacks
something else
take your pick.
A lot of people observe their tube amps seem to lose their punch as the night goes on, 99% of the time this can be attributed to stage volume hearing loss, the same scenario that causes musicians to demand their monitors get turned louder and louder as the night progresses.
Especially if the amp sounds fine again the next day, it's not the amp, it's you ;) I've done the above dance a few times with people, until we worked it out, in one case it involved an evening of having the guy sit outside the practice room, whilst someone else played his amp.
Microphonic tubes are vibration sensitive, take a plastic pen or something non-conductive, and rap on the tube, or the can of the tube if it's canned, do you hear it? If so, then yeah it's a microphonic tube. Noise is in the ear of the beholder, it's oftener bad power or bad cables, than bad tubes, if you've left the amp powered off for a really long time, like a couple of years or more, then it could be the caps, tubes tend not to age if they're not used, hence the high market value of NOS tubes. Tubes are sensitive to harsh use, and harsh handling, so if the amp has been thrown about the practice room, tubes could be bad. If the amp is quiet with the volume up or down, and no cable plugged in, then it's likely bad cable or extraneous noise.
The Butcher is very similar to my JCM800 in terms of design, those "low" input is in parallel with the high, so if the low isn't passing signal, you'll be losing volume. Use the cable/contact cleaner trick to clean it out. Clean all of the pots with the same contact cleaner, spray them and work 'em to and fro. Dirty, or loose-tensioned tube sockets also can cause intermittent bullshit noise. You can clean the tube sockets by spraying the base of the tube, and all of the pins with contact cleaner, then working them in and out a few times in circular fashion. Sockets need to be re-tensioned after a couple tube changes, it's the same idea as stretching out a spring, once it's "sprung" it won't ever be the same again.
Perhaps we should do a legit "tube amp maintenance" thread, and sticky it... I can do the 800, and the Model T... which pretty much covers the Marshall-style and the Bassman style of amps...
The noise exists only in the peavey. The exact same setup cables,cab and all do not produce the noise on the mesa.
My mesa was noticably quiter and lacking punch. Even my band members noticed.
My old Butcher, now owned by nonoman, was dead quiet while I had it. The cleaning should clear up any noise in that amp, it's too simple not to do, IMO, it'll eliminate many of the common noise makers in amps. If it doesn't work, your next bet is microphonics, then caps.
The Mesa is most likely due to tired old tubes...
Different amps can have different susceptibility to noise. I can get away with using my crappy $1 cables on certain amps I own, and on some of the others it's terribly audible. With tube amps, different amps of the exact same type can act differently, due to differences between tubes, and of course as the life of the tubes goes on, the amp sounds different again.
Here's some checks:
Is it noisy with no cable on the input?
Is it noisy with a shorted jack on the input?
Is it noisy with a shorted jack on the FX loop return?
shorted jacks are wonderful things for finding a fault, or narrowing it down, get a jack, solder the terminals together, done.
Sunn, most amps have a lot of common ground, it would be a good idea to group things, like retensioning tube sockets, cleaning pots, etc together, and then have a separate post for amp specific gotcha's like preamp out / power amp in or fx loop gotcha's and that kind of thing.
That's what make tube amps fun, learn one, learn 'em all, start seeing where the similarities lie ;D
If the Butcher's tubes are so new, why not put them in the Nomad? It's all 6L6's right?
Mark each tube as you take it out of each amp, so you can return it to the same place, and mark the amp chassis, say use letters for the Butcher and numbers for the Nomad, so you can return everything to it's original state.
If it's just crud buildup on the tubes, even the act of taking 'em out and putting 'em in again helps.
Check that generic biasing video on eurotubes.com for a visual on how to clean tube sockets.
I gotcha, You want to make the thing or do you want me to do it, and you add your insight? It'll be a few days before I get a couple minutes at the bench, I have some other projects on it. If you've got a tube amp, and a camera, you can do the basics...
My tube amps might scare people ;D
Quote from: Hemisaurus on October 04, 2011, 05:11:43 PM
If the Butcher's tubes are so new, why not put them in the Nomad? It's all 6L6's right?
Mark each tube as you take it out of each amp, so you can return it to the same place, and mark the amp chassis, say use letters for the Butcher and numbers for the Nomad, so you can return everything to it's original state.
If it's just crud buildup on the tubes, even the act of taking 'em out and putting 'em in again helps.
Check that generic biasing video on eurotubes.com for a visual on how to clean tube sockets.
That's actually the plan tonight.
Ive got 911 on speed dial!
Mesa's are all fixed bias, as long as you've got a good set of matched power tubes, should be OK. Then again, most noise is in the preamp tubes anyways. Good preamp tubes are more important than good power tubes, you can limp along on older power tubes, but crapped out preamp tubes are going to make the whole thing sound bad.
For financial reasons I'm going to swap the Governors in my 2x12 for Swamp Thangs rather than buy a whole new 2x12 loaded. I want the cab to be 8 ohms. Do I get 16 ohm speakers or 8 ohm speakers and how do I wire it? Honestly I haven't Googled this yet but I can. I just want to make sure I do it correctly. I haven't soldered in 20 years but I'll figure it out or get an electronics friend to help.
Two 16 ohm speakers in parallel = 8 ohms
EDIT: FUCK YOU DROID X
Quote from: SunnO))) on October 05, 2011, 01:40:40 AM
Two 16 ohm speakers in parallel = 8 ohms.
Thank you sir!
Quote from: SunnO))) on October 05, 2011, 01:40:40 AM
Two 16 ohm speakers in series = 8 ohms.
In series, speakers impedance add, so that would be 32 ohms. If you need 8 ohms, parallel them.
Quote from: Hemisaurus on October 04, 2011, 09:11:43 PM
Mesa's are all fixed bias, as long as you've got a good set of matched power tubes, should be OK. Then again, most noise is in the preamp tubes anyways. Good preamp tubes are more important than good power tubes, you can limp along on older power tubes, but crapped out preamp tubes are going to make the whole thing sound bad.
The butcher is fixed bias as well.
That should make life easier. ;)
Whoa, my Droid X autocorrected me...
I need to clear that cache, yesterday, I emailed my mom and it put the word "cunt" in there, in place of "mom!"
No shit.
EDIT: As I was typing in JJ tubes to a friend, it popped in "series," after I deleted it, it popped in "parallel."
Wonky piece of shit. It just takes words you use a lot, and puts them in where it thinks you want them to go. I guess it was right about my mother.
You ain't the first and you won't be the last, Mr Sunn:
http://damnyouautocorrect.com/ (http://damnyouautocorrect.com/)
Man... poor bastards on that site. I'm turning it off.
(http://damnyouautocorrect.com/images/prius-sale.jpg)
(http://damnyouautocorrect.com/images/pregnant-daughter.jpg)
From another forum, anyone agree with this?
"Series wiring- mid/upper mid and high end emphasis generally, smoother high freqs generally due to damped top end highs in the 5 to 6k range, less fizz. Additional tonal changes are slightly spongier attack and altered OD character, more complex and timbrally rich with more overtones ala the mid and top end emphasis.
Parallel wiring- low end and lower mid emphasis with more top end high sparkle or fizz, depending on the speaker and rig that can make the high end raspy or harsh to some. Low end is emphasized due to increased damping between 2 12" speakers in parallel, generallly tighter and more thump."
???
Are they talking about wiring cabs or speakers? If cabs what kind of cabs, 2x12 4x12 and how are the speakers in the cabs wired?
I've never noticed a goddamn thing wiring cabinets differently. I even put an RTA to one in parallel, and one in series, and one combined cab, and there wasn't hardly any difference whatsoever, nothing noticeable visibly, or aurally.
They're just different ways for electricity to flow.
Quote from: SunnO))) on October 11, 2011, 01:46:18 PM
I've never noticed a goddamn thing wiring cabinets differently. I even put an RTA to one in parallel, and one in series, and one combined cab, and there wasn't hardly any difference whatsoever, nothing noticeable visibly, or aurally.
They're just different ways for electricity to flow.
this. i think that MAYBE it would sound different in a studio situation? even then only slightly. live i think all bets are off.
now that i think about it, it is just like someone saying "cabs sound different at different ohm's as well". i have never noticed a difference, but that's just me.
That's a total load of shit. That has to do with the efficiency of the amplifier, and if it runs differently at lower ohm loads. 16 ohms is the ~ideal~ ohm load to run an amp at, so any combination of cabs giving you an even 16 ohms (or very close) will sound different compared to four ohms, because the amp is being pushed differently.
Quote from: SunnO))) on October 11, 2011, 02:01:15 PM
That's a total load of shit. That has to do with the efficiency of the amplifier, and if it runs differently at lower ohm loads. 16 ohms is the ~ideal~ ohm load to run an amp at, so any combination of cabs giving you an even 16 ohms (or very close) will sound different compared to four ohms, because the amp is being pushed differently.
so i should run my cabs at 16 ohms? hmm. interesting. i've always been a 4 ohm man myself. not sure why, that's just how they came wired.
~in theory~ yes.
I forget who told me this, I'm almost sure it was John McNeece, he was my amp tech until he moved, and I spent a great many hours talking to him. I feel like this is something he said. Therefore, to me, it's golden.
Err no, I said it, in the very first post of this thread ;D
but it only applies to tube amps.
There's no way you can make a blanket statement about speakers in series vs. parallell, it's going to depend on the iindividual speakers, cabinets and the amp driving them. You can do complex mathematical modelling of it, or you can listen, or you can post on internet forums.
Sorry, dear.
~props to you~
cant believe how many time i discuss impedance of an amp. Makes me think it should be required when buying one to watch an informational video
Quote from: dunwichamps on October 11, 2011, 11:35:39 PM
cant believe how many time i discuss impedance of an amp. Makes me think it should be required when buying one to watch an informational video
I'm more of a forgeter than a learner. I learn just enough to get my gear set up and then I try to just concentrate on the music part.
Quote from: moose23 on October 11, 2011, 01:21:02 PM
Are they talking about wiring cabs or speakers? If cabs what kind of cabs, 2x12 4x12 and how are the speakers in the cabs wired?
Wiring.
http://www.thegearpage.net/board/showthread.php?t=427484
hemi, how hard is a series "splitter" speaker box to make? i have two 4 ohm cabs, want to run them together with my head . . . go!
Quote from: justinhedrick on October 12, 2011, 10:48:15 AM
hemi, how hard is a series "splitter" speaker box to make? i have two 4 ohm cabs, want to run them together with my head . . . go!
I assume you mean that you amp has only one output tap?
If you want a splitter to split it into 2 output jacks, literally anyone could built that
Or do you mean you want to stack the 2 4 ohms to get 8 ohms.
That is doable 2
i want to stack the two 4 ohm loads into an 8 ohm load.
its going to be a little tricky,
You need to rewire the cabs so that you have an in and out jack on both. Then you run those cables back to a spitter box so you can wire them correctly.
Doable, but dirty
Unless the cabs can be rewired themselves. are they 1x12 or 2x12 or 4x12?s
Quote from: dunwichamps on October 12, 2011, 11:19:36 AM
its going to be a little tricky,
You need to rewire the cabs so that you have an in and out jack on both. Then you run those cables back to a spitter box so you can wire them correctly.
Doable, but dirty
Unless the cabs can be rewired themselves. are they 1x12 or 2x12 or 4x12?s
they are 2x15s. wired to 4 ohms. so couldn't a box that makes them a series/parallel wired set? like a 4x12 cab usually is?
You need to have access to the speaker leads without them being tied to ground in anyway. Why dont you just rewire the cabs to be 16 ohms, then // them with a box. Thats a lot easier.
i could do that too.
then you just get a simple 1 jack in, 2 jacks out splitter.
http://sunn.ampage.org/sdp/index.php/topic,5502.0.html (http://sunn.ampage.org/sdp/index.php/topic,5502.0.html)
Here ya go!
Use a plastic project box, remember that.
or you can use insulated jacks. Cliff Marshall Style Jacks are isolated so you could use them with a Hammond chassis.
i guess i was overthinking this problem. oops
you could even through in a switch to change from series to parallel
They sell those at the Shack? ::)
Quote from: SunnO))) on October 12, 2011, 12:22:53 PM
They sell those at the Shack? ::)
No but I can get you wholesale prices, shipped to your door
If you need a deal on something, let me know I can pass along my prices to you directly
(tubes, pots, caps, transformers, ICs, Semiconductors...)
The big bugger is we can't see the prices, until we get an account, sigh >:(
Quote from: Hemisaurus on October 12, 2011, 12:41:31 PM
The big bugger is we can't see the prices, until we get an account, sigh >:(
Just ask, ill let u know
email me for info, dunwichamps@gmail.com
oooo... Kickass...! ;D ;D ;D
So I saw this on the Bay; probably too much money, no?
http://www.ebay.com/itm/200-watt-tube-amp-chassis-rebuild-parts-/380372753328?pt=LH_DefaultDomain_0&hash=item588ffb9bb0
I've built several amps, from Champ copies and tweed Deluxes to a Metroamp kit for a Marshall 1987. I've got an itch to put together a KT88 head with a modified Marshall preamp. Nothing too complicated. Slightly off topic: is there really any difference in assembling a 50W amp and a 200W amp (besides component differences, obviously). I mean as far as assembly techniques, testing, etc. There seems to be a lot of fear, but the way I see it, 400 volts DC kills you just as dead as 700 volts DC. Proper protection is proper protection, right?
No huge difference, just number and type of tubes. Might not be that large a plate voltage, I don't think KT88's do 700V.
Things to watch for are make sure the power supply you design is adequate, and that the driver circuit is appropriate for the tubes. Watch for the attenuation value if you add an NFB loop, have fun.
Have a look at other quad KT88 designs, see what they use for phase splitter / driver.
Hmm, looking at several driver designs (Marshall Major, Marshall VBA400, Hiwatt 200, Sound City LB200, Sunn 2000S), it seems that many designs don't change all that much. It's only when you get to more than four tubes that driver designs change. The Sunn, for example, has the same driver (6AN8) as the Sunn 200S (2x KT88). Maybe I'm not looking close enough. Also the Hiwatts have that complicated LTP design with DC bias from a cathode follower.
Just use an LTPI any old marshall uses. You should optimize the driver tube selection, 12ax7 make not be the best here, maybe a 12at7 or 12au7 if your looking for the headroom in the driver stage
I have built a version of the Sunn driver which uses an EF86 and a 12au7 as 6an8s are not in production anymore. Its pretty good but nothing special in terms of 50W versus 100W versus 200W
Kt88s can handle 700V on the plate but screens cannot exceed 600V (http://lib.store.yahoo.net/lib/thetubestore/JJ-KT88.pdf) Make sure you have a large dropping resistor after the choke (10W or 5W resistor) to bring down the voltage below the limit.
If I had a grand, I'd do the Marshall 1959 kit
Quote from: SunnO))) on October 15, 2011, 12:59:03 PM
If I had a grand, I'd do the Marshall 1959 kit
Which brand? Ceriatone or Weber?
Like Duwich said, that new Weber kit is only $515
(https://taweber.powweb.com/store/8cm100.jpg)
$515
Replicates the signature roar of hard rock bands. Single channel 100 watt head with full Tone Stack, Presence, and MV.
There's not a lot of difference between MV and non-MV.
Hey Dunwich, have you got another name, or should me continue to call you Dunwich?
Ceriatone, Nick.
You can call me Dunwich or Nick, some people know my name some people dont its kool i respond to either
Ceriaton makes a nice kit but the shipping is nuts. Weber is more budget and I would recommend upgrades for even a moderate level builds (Tubes and Pots) which will bring up the price to ~650 (plus ship) A must upgrade is Jacks for weber kits.
The 8cm100 kit could be made into a SL type but the input jack setup is not the same as an SL but if you dont mind that then its all good.
In general upgrades for a Weber kit are:
(Tubes, Pots, Switches, Jacks, Impedance Selector).
Weber iron is pretty good. I have never had any problems, there PTs run cold and there OTs are good for the price.
I had thought about a Weber Kit being a cheaper way to get the chassis, xfmrs, headcase altogether than separates, until this Crate fell into my lap. I'll be gutting it, probably next year the speed things move right now.
I had thought of doing a Sunn Model T with just the Both jack on something, I don't know if anyone ever uses the other four ;D
I guess I'll stick with Dunwich, though I seem to keep dropping the n and making you Du'Wich which may be your French name?
I think a nice 100W build would be some generic 100W'r from whoever, and then build it to taste, and at some later point upgrade the OP xfmr to the MC one which is like a $70-80 upgrade if memory serves.
That eylet board on your Metro amp looks nice, is that the Weber one?
Quote from: Hemisaurus on October 15, 2011, 03:21:08 PM
I had thought about a Weber Kit being a cheaper way to get the chassis, xfmrs, headcase altogether than separates, until this Crate fell into my lap. I'll be gutting it, probably next year the speed things move right now.
I had thought of doing a Sunn Model T with just the Both jack on something, I don't know if anyone ever uses the other four ;D
I guess I'll stick with Dunwich, though I seem to keep dropping the n and making you Du'Wich which may be your French name?
I think a nice 100W build would be some generic 100W'r from whoever, and then build it to taste, and at some later point upgrade the OP xfmr to the MC one which is like a $70-80 upgrade if memory serves.
That eylet board on your Metro amp looks nice, is that the Weber one?
A Model T could be built out of the SL kit, since a Model T is very close to that circuit.
Metro eyelet board is Weber but i will not be using it for future Metros it will be a custom turret
I've got an 70's tube amp that's been in storage but only for the last 2 years. Can I just fire that baby up and not worry about it? It's was serviced prior to storage, electrolytic's in spec, biased etc. I don't have a variac or "ramp-up" power device - is that something I should consider? Thanks Tube wizards...
If it has been completely recapped when it was last serviced, you should be OK, modern electrolytics tend to be a little hardier. If it's got some older caps in there, then you might want to get it re-reserviced.
QuoteCap Jobs - Do I need one? How often? Why?
What's a cap job? A technician may recommend you have a "cap job". This means that he will replace every single electrolytic capactor in the amp, from the power supply right down to the cathode bypass caps.
This is because electrolytic (polarized) capacitors have an inherent wear-out mechanism and will eventually die even if you don't play death/metal/country/barbershop through them every day - in fact they may wear out sooner if you leave it sitting in the attic. Here's why.
A capacitor is essentially two conductive plates separated by an insulator. The bigger the plate area and the thinner the insulator, the higher the "capacitance" is. Electrolytic capacitors get a very thin insulator by "growing" an insulating layer of aluminum oxide on the outside of a rolled up piece of aluminum foil.
The oxide layer is "formed" at manufacture by feeding the aluminum foil a very small and carefully controlled amount of current. The current causes a chemical reaction between the foil and the water solution (electrolyte! ... hey... is that where they got the name?? yep.) which makes an oxide layer grow. As the layer grows, they use higher and higher voltages to force the same small current through the layer, which gets thicker and more resistive with time. When they have to use the full rated voltage to get the forming current through, the cap is fully "formed" and ready to ship.
If the capacitor is used regularly, has voltage applied to it, and does not get too hot, the oxide film lasts up to a few decades. If the capacitor is not used much, or gets too hot, the oxide film slowly un-forms, the leakage current goes up, and it will eventually short.
Electrolytic caps are designed to last ten years. It is a tribute to the quality of manufacture that they often last three, sometimes four times that.
Old amps, particularly if they have not been used regularly need to have every electrolytic cap replaced. This cap job may be needed every ten or so years.
Non-electrolytic caps do not have this wear out mechanism, and do not need replaced for this reason. Modern capacitors can in some circumstances be much better than old ones, and you can sometimes get a clearer, more sparkly tone by changing the non-electrolytic caps - assuming that is something you want to do.
Do new caps need to be formed?
There's a lot of controvery on "reforming" replacement caps. Here are a few answers.
Manufacturers of caps design their caps for a ten year working life, and a five year shelf life. That means that the stresses and heat of working in equipment will leave the vast majority of caps functioning OK after ten years of normal operation. After that, it's gravy to the buyer.
They also design them to work OK after sitting on a shelf unused for five years, meaning that the cap should not fail if it's put into operation at rated voltage after sitting unused for five years. As noted above, the caps do slowly un-form without regular use.
If the electrolytic caps you use to fix your amp are over five years old as determined by the date code on them, you ought to at least worry about forming them, and if they're over ten years old (like NOS multisection cans), definitely re-form them. Other than that, put them in and turn it on.
How do I "re-form" electrolytic caps?
You'll hear folks talk about "bringing an amp up slowly on a variac"; this can work but is not particularly good for your tubes. A better way is this:
Pull out all the tubes.
if your amp has a tube rectifier, solder in temporarily some high voltage silicon diodes across the tube lugs to be a rectifier that does not depend on the filament voltages. If your amp has silicon diodes, you can skip this.
open up the wire that goes from the rectifier tube (or solid state diodes) to the first power supply filter stage and solder in series with the wire a temporary 100K 2- 5W resistor. This resistor will limit the current that can flow into the caps and the amount of voltage that is applied to them to safe values that will cause the insulating layer to re-form.
clip your voltmeter across the resistor
button it up. Turn it on (no tubes in it, remember). Watch the voltmeter.
when the voltmeter reading drops to less than 20-30VDC, your caps are formed.
open it back up and pull out those diodes and resistor, putting it back in original shape.
The forming could take hours to days.
Thanks for the informative reply, Hemisaurus!
Well that's from the GeoFex tube maintenance FAQ, it just saves me typing it all out myself ;D
When working on tube amps, remember
(http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc7/317141_2323849749082_1634761418_2238874_644960020_n.jpg)
http://www.eminence.com/support/wiring-diagrams/
So for wiring a 2x12 parallel I'll be pealing the plastic coating in one small spot for each wire to attach the branch off by twisting the connecting wire and then soldering and taping with electrical tape? I want to do this correctly. 8 ohms just makes sense so if I do end up using a solid state amp I'll have more power on tap but I can still use a tube amp as well.
Get push-on connectors. Never solder directly to the tabs.
Sent from my DROIDX using Tapatalk
Get the push on connectors as sunno says for connecting to the speakers and run wires from both speaker negatives back to the jack socket on the cab and solder them both to sleeve of the jack. Then for the positive of each speaker run the two wires back to the tip of the jack socket and solder. No need for tape.
So you are getting two 16 ohm speakers, and wiring them in parallel for 8 ohms?
There's pluses and minuses with wiring direct to the speaker tab.
Pluses
- It's Cheap
- It's a better connection, less power is lost than in a push-on
Minuses
- Less Flexible, if you want to change the wiring quickly
- Might harm the resale value of the speaker, some people are funny about it
Also it's not always easy to find the right size of spade (push-on) clip, the ones at the auto store are too big usually.
I have speakers wired both ways, soldered on, and push on, but the best are the big PA drivers that have spring terminals on the speaker. ;D
I use high end gold spades. Any place that does car audio has them. If they're too big, they can be collapsed to fit tightly. Done it a thousand times. Never an issue.
i always crimp, then solder my spades to the wire. Then heatshrink or tape. Call it overkill, I call it thorough.
Sent from my DROIDX using Tapatalk
Car audio, those places are prolific, duh ::)
and then just push 'em on?
My preference is for tinned wire into a spring terminal, and if I'm pushing more than a few hundred watts, and don't have a spring terminal, I'm going to solder, that .5 ohm or so you might lose in the contact actually starts counting, and getting warm. For guitar cabs though, spade terminals make life much easier. You know that contact between two unlike metals is worse? So copper to gold, and then gold to whatever they make the terminal from, which now I think about it, I have no idea what that stuff is.
If you overkill the spade, your making it less flexible, and putting more strain on the tab on the speaker itself, so it may snap off, like running a lead pipe where you should use a flexible hose.
Ah.. fuck it, I'm taking it in, if the price is right. But thanks for the info.
Don't do that, that's what the man wants you to do. Depending on your soldering skills, might be less risky and tidier to use spade connectors, though you'd ideally want the proper crimp tool for them. Get the uninsulated connectors so you can give 'em a squeeze if they're slighty loose and sloppy. Mmmmm. I wouldn't think you'd have issues as long as they're snug. You see them inside appliances with decent loads, such as in ovens on the energy regulators and thermostats and selector switches.
I'll have to see when I get the new speakers(on order) and open up the cab. I just want it to get done right and don't want to spend 6 hours on it.
We can just make you a simple diagram?
He has the diagrams, he's just been confused by our conflicting opinions. I'm surprised companies don't sell wiring rigs, for speaker cabs, buy the jack, the spade leads etc. all in one pack, Sunn here's a golden business opportunity for you ;)
Quote from: Hemisaurus on October 25, 2011, 03:23:28 PM
He has the diagrams, he's just been confused by our conflicting opinions. I'm surprised companies don't sell wiring rigs, for speaker cabs, buy the jack, the spade leads etc. all in one pack, Sunn here's a golden business opportunity for you ;)
that's a great idea. market them as "oxygen free, titanium plated, super leads"
Well there's Monster, so why not Gator for the swampboy, oh wait that's been taken already ;D
Quote from: Hemisaurus on October 25, 2011, 03:39:41 PM
Well there's Monster, so why not Gator for the swampboy, oh wait that's been taken already ;D
hmm. that's a tough one . . . it's not nearly as easy as naming cables for our neck of the woods: Corn Country Cables! ;D
"Corn connectors"
or
"Haggis Rigs"
Don't take that shit in, and pay 40 bucks to fucking have someone pop on 6 connectors. That's straight-up bullshit, man.
I'll use some loose speakers around here, and take pictures for you. This is easier than tying shoes, no shit.
He's right bro, shit's super simple. 6 hours?? More like six minutes, tops
"It's cinchy!"
You can send me 40 bucks though...
Sent from my DROIDX using Tapatalk
For forty dollars I'd wire up a jack or two (for parallel wiring a second cab) to a bunch of spade connectors, label them clearly and post them from Ireland to wherever you are.
Quote from: SunnO))) on October 25, 2011, 04:11:50 PM
"Corn connectors"
or
"Haggis Rigs"
Don't take that shit in, and pay 40 bucks to fucking have someone pop on 6 connectors. That's straight-up bullshit, man.
I'll use some loose speakers around here, and take pictures for you. This is easier than tying shoes, no shit.
Dude, I'm covered don't you worry about me, when I make cables I(http://dub.greboguru.org/plugit.png)
Say, Herb, you got a source for bulk instrument cable? I need to make my pedalboard a little less fuckin' dinky patch cably, and a little more "everything reaches and looks nice."
Angled male ends, too? Mouser?
I'm just burnt on equipment is all. I sing and play through 2 amps and I still don't have all the right gear yet and set up in the right way and it seems like I've been accumulating and setting up gear for a long time. But I know that I'm very close to having things right.
Okay so I get the right size spade leads(what size? can/should I get them at Radio Shack or at a car audio place? what do they look like?) hook up the wiring one of 2 ways and I don't need to solder anything? I will have to strip some wire though right? So I need a tool for that or can I just use a box cutter and be careful? Electric tape, I have that, I should use it, no?
Just ignore all of this aside from the spade leads part, I'm clueless on that.
Anyone want a brand new size medium Deep Purple Machine Head t-shirt? It doesn't have the album cover on it but it does have a picture of the band and it says Deep Purple Machine Head. If you might wear it I'll send it to you, just PM me. I'd wear it but I already have an In Rock album cover shirt.
(http://fzronline.com/graphics/forum/spade_connector.jpg)
(http://t0.gstatic.com/images?q=tbn:ANd9GcSwEU7vOtcmyurmTz8qgl0gAVZYSUehaR1QFCTdUqsfgQwU0iQLRQ)
Those pliers have a stripping element (the holes down by the handle) but I just melt a quarter inch of the plastic off w/ a lighter (Protip: Inhale the fumes, it makes the job more doomy. j/k) Twist the bare strands together tightly, insert into the end and staaaat clampin'. Tug to ensure it's tight (that's what she said)
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=095-280 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=095-280)
http://www.amazon.com/Gardner-Bender-GS-394-Stripper-Crimper/dp/accessories/B0018ZHTWS (http://www.amazon.com/Gardner-Bender-GS-394-Stripper-Crimper/dp/accessories/B0018ZHTWS)
Bam.
Thanks guys.
I'll knock off the whining from here on out, I promise.
Burnt out? You have the rest of your life to do this, hahha.
thats why i just build it instead
Endless tweaking, that's what I fear ;)
You know you're getting on, when you stop building just for sound, and start building for portability too.
Quote from: Hemisaurus on October 26, 2011, 04:05:50 PM
Endless tweaking, that's what I fear ;)
You know you're getting on, when you stop building just for sound, and start building for portability too.
endless building, never really satisfied
althought i love coming up with new amps to build
i just made another idea for myself 2, Fog Machine
Quote from: dunwichamps on October 26, 2011, 04:07:59 PM
Quote from: Hemisaurus on October 26, 2011, 04:05:50 PM
Endless tweaking, that's what I fear ;)
You know you're getting on, when you stop building just for sound, and start building for portability too.
endless building, never really satisfied
althought i love coming up with new amps to build
i just made another idea for myself 2, Fog Machine
build one with a decent pump, that's what usually goes, or the heating element burns out.
Quote from: Hemisaurus on October 26, 2011, 04:09:18 PM
Quote from: dunwichamps on October 26, 2011, 04:07:59 PM
Quote from: Hemisaurus on October 26, 2011, 04:05:50 PM
Endless tweaking, that's what I fear ;)
You know you're getting on, when you stop building just for sound, and start building for portability too.
endless building, never really satisfied
althought i love coming up with new amps to build
i just made another idea for myself 2, Fog Machine
build one with a decent pump, that's what usually goes, or the heating element burns out.
lol thats the name of the amp
It's a concept though, can you heat the fog juice via the heat from the tubes, have the amp puff smoke at high gain ;D
Quote from: dunwichamps on October 26, 2011, 04:13:11 PM
Quote from: Hemisaurus on October 26, 2011, 04:09:18 PM
Quote from: dunwichamps on October 26, 2011, 04:07:59 PM
Quote from: Hemisaurus on October 26, 2011, 04:05:50 PM
Endless tweaking, that's what I fear ;)
You know you're getting on, when you stop building just for sound, and start building for portability too.
endless building, never really satisfied
althought i love coming up with new amps to build
i just made another idea for myself 2, Fog Machine
build one with a decent pump, that's what usually goes, or the heating element burns out.
lol thats the name of the amp
going for a midrange-y foggy tone?
Quote from: Hemisaurus on October 26, 2011, 04:16:21 PM
It's a concept though, can you heat the fog juice via the heat from the tubes, have the amp puff smoke at high gain ;D
i guess thats true. i was figuring i would have a well done etched plexi piece building on the fog thing, who knows
idea would be a gap between the NMV Wizards and the MV Wizards i built but more traditional phase inverter for Oranges
Are Wizards something of yours, or are you referring to the amp company with the same name (as used by AC/DC I believe)?
Quote from: Hemisaurus on October 26, 2011, 04:21:55 PM
Are Wizards something of yours, or are you referring to the amp company with the same name (as used by AC/DC I believe)?
ppl confuse them on forums but if I use the word Wizard i am referring the amps that i built with those names
Fog Machine would be like a way to go from a cleaner vintage Orange (but not tooo clean) up to a pretty gainy Matamp/EA (but not as gainy as the wizard with a master volume)
Quote from: dunwichamps on October 26, 2011, 04:29:12 PM
Quote from: Hemisaurus on October 26, 2011, 04:21:55 PM
Are Wizards something of yours, or are you referring to the amp company with the same name (as used by AC/DC I believe)?
ppl confuse them on forums but if I use the word Wizard i am referring the amps that i built with those names
Fog Machine would be like a way to go from a cleaner vintage Orange (but not tooo clean) up to a pretty gainy Matamp/EA (but not as gainy as the wizard with a master volume)
I guess they haven't heard about you yet, he says posting to info@wizardamps.com ::)
Quote from: Hemisaurus on October 26, 2011, 04:38:23 PM
Quote from: dunwichamps on October 26, 2011, 04:29:12 PM
Quote from: Hemisaurus on October 26, 2011, 04:21:55 PM
Are Wizards something of yours, or are you referring to the amp company with the same name (as used by AC/DC I believe)?
ppl confuse them on forums but if I use the word Wizard i am referring the amps that i built with those names
Fog Machine would be like a way to go from a cleaner vintage Orange (but not tooo clean) up to a pretty gainy Matamp/EA (but not as gainy as the wizard with a master volume)
I guess they haven't heard about you yet, he says posting to info@wizardamps.com ::)
someone suggested changing the name but i say i dont give a fuck really. Its just one of the models i offer and technically its the Dunwich Wizard so no biggie
Quote from: dunwichamps on October 26, 2011, 04:44:24 PM
Quote from: Hemisaurus on October 26, 2011, 04:38:23 PM
Quote from: dunwichamps on October 26, 2011, 04:29:12 PM
Quote from: Hemisaurus on October 26, 2011, 04:21:55 PM
Are Wizards something of yours, or are you referring to the amp company with the same name (as used by AC/DC I believe)?
ppl confuse them on forums but if I use the word Wizard i am referring the amps that i built with those names
Fog Machine would be like a way to go from a cleaner vintage Orange (but not tooo clean) up to a pretty gainy Matamp/EA (but not as gainy as the wizard with a master volume)
I guess they haven't heard about you yet, he says posting to info@wizardamps.com ::)
someone suggested changing the name but i say i dont give a fuck really. Its just one of the models i offer and technically its the Dunwich Wizard so no biggie
Long as you don't try a Disney. Buddy of mine called his company Buena Vista something or other, lawyers letters came soon after.
Quote from: dunwichamps on October 26, 2011, 04:44:24 PM
Quote from: Hemisaurus on October 26, 2011, 04:38:23 PM
Quote from: dunwichamps on October 26, 2011, 04:29:12 PM
Quote from: Hemisaurus on October 26, 2011, 04:21:55 PM
Are Wizards something of yours, or are you referring to the amp company with the same name (as used by AC/DC I believe)?
ppl confuse them on forums but if I use the word Wizard i am referring the amps that i built with those names
Fog Machine would be like a way to go from a cleaner vintage Orange (but not tooo clean) up to a pretty gainy Matamp/EA (but not as gainy as the wizard with a master volume)
I guess they haven't heard about you yet, he says posting to info@wizardamps.com ::)
someone suggested changing the name but i say i dont give a fuck really. Its just one of the models i offer and technically its the Dunwich Wizard so no biggie
i could understand the confusion but in reality i don't think Wizard is a big enough company to worry about people confusing the two. but if you get a cease and desist letter, then you'd have to change the name.
Quote from: justinhedrick on October 26, 2011, 04:49:21 PM
Quote from: dunwichamps on October 26, 2011, 04:44:24 PM
Quote from: Hemisaurus on October 26, 2011, 04:38:23 PM
Quote from: dunwichamps on October 26, 2011, 04:29:12 PM
Quote from: Hemisaurus on October 26, 2011, 04:21:55 PM
Are Wizards something of yours, or are you referring to the amp company with the same name (as used by AC/DC I believe)?
ppl confuse them on forums but if I use the word Wizard i am referring the amps that i built with those names
Fog Machine would be like a way to go from a cleaner vintage Orange (but not tooo clean) up to a pretty gainy Matamp/EA (but not as gainy as the wizard with a master volume)
I guess they haven't heard about you yet, he says posting to info@wizardamps.com ::)
someone suggested changing the name but i say i dont give a fuck really. Its just one of the models i offer and technically its the Dunwich Wizard so no biggie
i could understand the confusion but in reality i don't think Wizard is a big enough company to worry about people confusing the two. but if you get a cease and desist letter, then you'd have to change the name.
they have never troubled me so unless i get bigger than what I am i doubt i would catch much flak.
I try to remember all this hardware is to facilitate the writing and playing of songs.
It doesn't always work for me ;D
Quote from: Hemisaurus on October 26, 2011, 03:40:21 PM
Researching gear, is like dancing about architecture, to quote Frank Zappa.
Seriously, all the research in the world isn't going to help until you are in the room with it.
But my friends, Guitar Center and the last indie shop in town don't sell everything. You can learn a lot buy researching gear online- reading reviews, product websites, posting on forums, Youtube videos, etc.
You live in Madison, you're set for gear.
Quote from: liquidsmoke on October 27, 2011, 12:10:10 AM
Quote from: Hemisaurus on October 26, 2011, 03:40:21 PM
Researching gear, is like dancing about architecture, to quote Frank Zappa.
Seriously, all the research in the world isn't going to help until you are in the room with it.
But my friends, Guitar Center and the last indie shop in town don't sell everything. You can learn a lot buy researching gear online- reading reviews, product websites, posting on forums, Youtube videos, etc.
Research is useful if you know how to tell real info from marketing BS and people wanting to tell everyone how great their stuff is. Problem is for example, to determine how a speaker sounds just below 200hz takes about 15 values, a bunch of maths and the ability to read the resulting chart. Then when you take your results to tell someone why their shit keeps blowing up they'll say something like 'But I read on the internet that Stevie-Ray Vaughn did it'.
I didn't want to sound condescending saying something like, unless you've got a lot more experience. Even with experience you're still only guessing.
The Youtube videos though are funny, sure you are hearing the gear, but what was used to make that recording, was there any post processing done, was it EQ'd at the time, and what sort of encoding algorithm as Youtube used on the original file? How accurately is your computer going to reproduce all that anyway? Some video's I've seen, they at least try and give you an idea of the recording chain, which is nice.
Then there's the how does it sound with my gear? question. I had this totally awesome sound yesterday using a new preamp, halfway through I changed my bass, and it sounded terrible, no amount of dialling in seemed to get that sound, swapped back, there was the sound again. On my usual amp, there's very little difference in sound between those two basses, I generally just tweak the gain.
I hear you guys but Harmony Central reviews and forums like this and Youtube even are a great way to find out about gear in the first place and get an idea of what options are available, that's all I really meant. I've played stuff in stores and ordered gear online that didn't work for me for one reason or the other. I do what I can to make good decisions but yes in the end it's got to work out well in your rig at your space or it's worthless.
edit: info on watts, features, price, and overall reliability are other things one can usually find out online.
When I was car shopping I spend hours and hours online before going to any car lots, of course I was researching features, prices, reliability, etc, not the tone of the engines or feel of the driver's seats ;D
Can a 600 watt powered floor PA/monitor unit get a lot louder with vocals running into it before it starts feeding back than a similar 200 watt unit?
Not really, no. Rooms can take a certain amount of volume, and then you have to start repositioning speakers, moving mics, etc. Try them usual sound dampening tricks, like if the speaker is facing you, hang a blanket behind you, so the sound doesn't bounce of that wall, or adjus the mic so the reflections are in it's dead spot. It takes a lot of fucking about, it's often easier to just turn everything else down.
I'm going to be putting up some foam this week, hopefully that will help. Can't really turn down cymbals much. My amps are only loud enough so that I can hear them over the drums and through my earplugs.
I'm using a borrowed monitor unit so I have to give it back and buy my own at some point.
Quote from: liquidsmoke on October 29, 2011, 03:57:11 PM
Can a 600 watt powered floor PA/monitor unit get a lot louder with vocals running into it before it starts feeding back than a similar 200 watt unit?
feedback depends on everything else in the chain feeding back. Watts don't mean anything most of the time, so there is not gonna be any difference if that is the only factor changing, but inevitably other stuff will change with it. Bit of general awareness of the mechanics of feedback helps, sound has to be getting from source to mic, so the pickup pattern of the mic is pretty important, and as said, sound bouncing off a wall is a pretty likely factor.
Quote from: liquidsmoke on October 30, 2011, 03:18:52 PM
I'm going to be putting up some foam this week, hopefully that will help. Can't really turn down cymbals much. My amps are only loud enough so that I can hear them over the drums and through my earplugs.
I'm using a borrowed monitor unit so I have to give it back and buy my own at some point.
If you are using earplugs, you probably are already in trouble. If you're using earplugs, either you're already too loud, or your place is too small. Don't know how practical it is for you to get more space, last band I was in that used earplugs, was in the corner of a basement, we just took down the walls and used the whole basement, and that really helped, just having more space. You can simulate it with blankets and foam, but if you can find a bigger space life will be easier. Or have the drummer play with something like lightning rods, or brushes, or dampen the cymbals a bit more.
It's a lot easier than carpetting the walls.
Quote from: Mr. Foxen on October 30, 2011, 03:46:54 PM
Quote from: liquidsmoke on October 29, 2011, 03:57:11 PM
Can a 600 watt powered floor PA/monitor unit get a lot louder with vocals running into it before it starts feeding back than a similar 200 watt unit?
feedback depends on everything else in the chain feeding back. Watts don't mean anything most of the time, so there is not gonna be any difference if that is the only factor changing, but inevitably other stuff will change with it. Bit of general awareness of the mechanics of feedback helps, sound has to be getting from source to mic, so the pickup pattern of the mic is pretty important, and as said, sound bouncing off a wall is a pretty likely factor.
The monitor is pointed right at the mic which is also right where my head is when I'm singing, no real way around this. Hopefully foam will help. I have some tapestries hung up but they are pretty thin.
Quote from: Hemisaurus on October 30, 2011, 07:03:52 PM
Quote from: liquidsmoke on October 30, 2011, 03:18:52 PM
I'm going to be putting up some foam this week, hopefully that will help. Can't really turn down cymbals much. My amps are only loud enough so that I can hear them over the drums and through my earplugs.
I'm using a borrowed monitor unit so I have to give it back and buy my own at some point.
If you are using earplugs, you probably are already in trouble. If you're using earplugs, either you're already too loud, or your place is too small. Don't know how practical it is for you to get more space, last band I was in that used earplugs, was in the corner of a basement, we just took down the walls and used the whole basement, and that really helped, just having more space. You can simulate it with blankets and foam, but if you can find a bigger space life will be easier. Or have the drummer play with something like lightning rods, or brushes, or dampen the cymbals a bit more.
It's a lot easier than carpetting the walls.
There is one wall I could knock out, the room is fairly small right now. Do lightning rods quiet down cymbals? I have some carpet on one wall already and have more I can put up.
Regarding earplugs, I use them because I value my hearing. I wear them at shows too. Even if we practiced in an open field outside and the drummer was 20 feet from me I'd still want to wear plugs because if I didn't my ears would ring after every practice. Brushes for heavy metal? If my amp is above 1 my ears will ring, at practice it's about 2&1/2 or so. Maybe the problem is that I still have some hearing left so my ears ring. I think a lot of more seasoned rockers don't really notice ear ringing anymore because they are so used to it. My dad is rarely around loud sounds and his hearing is already getting somewhat bad at age 61, that has me somewhat concerned about my future.
The bitch is that without earplugs I can hear my vocals just fine... and then my ears are ringing really bad the rest of the day. All I need is a bit more vocal volume and I'll be fine. I hope the foam and more carpet does the trick.
I wear earplugs, anyways, too.
Quote from: liquidsmoke on October 29, 2011, 03:57:11 PM
Can a 600 watt powered floor PA/monitor unit get a lot louder with vocals running into it before it starts feeding back than a similar 200 watt unit?
Yes. Provided other changes are made, mainly utilizing the headroom provided by the additional 400 watts. The most efficient means for said headroom utilization would be a reduction in gain on the channel strip at the mixer(?) provided there is one, allowing the same volume or greater to be met with less gain. If the identical gain structure that the 200 watt monitor had going through it is pumped into the 600 watt monitor it could possibly feedback at even less volume. Is there a graphic eq for the signal to pass through before being amplified? If so I would set it flat and find the frequencies that are feeding back and pull them gently until feedback in that range leaves, as that should also obtain further headroom. If you don't have a graphic you can use the eq on the strip to help eliminate the problem frequencies.
wouldn't it depend moreso on the mic, the quality of it to reject feedback, its pattern and placement etc? Honest question so I'm not challenging the headroom issue.
The setup is- Sure SM-58 > Boss VE-20(digital vocal effects pedal) > Behringer power PA monitor. No mixer or graphic eq. I can try to turn the Behringer's volume up higher and the Boss' lower and see if that helps.
Quote from: liquidsmoke on October 30, 2011, 11:30:34 PM
Quote from: Mr. Foxen on October 30, 2011, 03:46:54 PM
Quote from: liquidsmoke on October 29, 2011, 03:57:11 PM
Can a 600 watt powered floor PA/monitor unit get a lot louder with vocals running into it before it starts feeding back than a similar 200 watt unit?
feedback depends on everything else in the chain feeding back. Watts don't mean anything most of the time, so there is not gonna be any difference if that is the only factor changing, but inevitably other stuff will change with it. Bit of general awareness of the mechanics of feedback helps, sound has to be getting from source to mic, so the pickup pattern of the mic is pretty important, and as said, sound bouncing off a wall is a pretty likely factor.
The monitor is pointed right at the mic which is also right where my head is when I'm singing, no real way around this. Hopefully foam will help. I have some tapestries hung up but they are pretty thin.
Depends heavily on the pickup pattern of the mic and the angle you ahve it at. Pointing at your head is pretty standard, but you can try Lemmying it if you usually have it pointed up at you.
Also, earplugs, are you using foamies or the rubber christmas tree jobs, some proper musicians earplugs will make a lot of difference as they have a more even response that won't force you to bump highs or overall volume yo hear yourself.
Quote from: liquidsmoke on October 31, 2011, 05:57:30 AM
The setup is- Sure SM-58 > Boss VE-20(digital vocal effects pedal) > Behringer power PA monitor. No mixer or graphic eq. I can try to turn the Behringer's volume up higher and the Boss' lower and see if that helps.
This should help at least a little. I would try to find a cheap graph, It would help a ton. Somewhere there is to much gain. LESS GAIN, MORE DRIVE
Quote from: HeavyEar on October 31, 2011, 04:06:11 AM
wouldn't it depend moreso on the mic, the quality of it to reject feedback, its pattern and placement etc? Honest question so I'm not challenging the headroom issue.
If gain structure is overlooked mic pattern and placement can only help to a certain extent. To change the mic to a hypercardioid would possibly provide some leniency, but nowhere near the amount if cleaner gain structure were followed with the initial mic. To have a wedge aimed at your head with a mic in front of you is about as standard as you can get. You could move the mic away from that spot and obtain some freedom from feedback but the volume gained would probably just be enough to compensate for the geographical change and not enough to truly alleviate the problem. By reducing the input gain and increasing the output wattage you can get more clean volume, and keep the mic right where you want it. This is a great topic!
Quote from: Mr. Foxen on October 31, 2011, 06:06:28 AM
Depends heavily on the pickup pattern of the mic and the angle you ahve it at. Pointing at your head is pretty standard, but you can try Lemmying it if you usually have it pointed up at you.
Also, earplugs, are you using foamies or the rubber christmas tree jobs, some proper musicians earplugs will make a lot of difference as they have a more even response that won't force you to bump highs or overall volume yo hear yourself.
My voice sounds better with my head pointed slightly down into the mic, can't do the Lemmy thing. This also allows me to easily look at my fretboard when I need to while singing.
I use Hearos, I probably spelled that wrong. They work pretty good. My ears ring a little bit after practice but they are much better than the foam ones.
Hey folks,
So I'm getting a "pop" in my Bogen CHB50 when I peg it I'm also getting a faint, distant ringing almost like it's a reverb spring, but the amp doesn't have one. The guy I bought it from told me NOT to set the head on top of the cab. Of course I did the opposite. It looks cool, plus I don't have anywhere else to put it 'cept for the floor. And I'm not putting it on the floor. The 6L6's are original Bogen's. It only does this once in a while and only when it's pegged. The pre-amp tubes are pretty new he said. I want to switch to EL 34's and see if I need to change caps, resistors, etc. to park it in Plexi-Land permanently. Supposedly it's a Bassman circuit knock-off. 50 Watts.
Are the power tubes going?
Quote from: Baltar on November 08, 2011, 02:44:26 PM
Hey folks,
So I'm getting a "pop" in my Bogen CHB50 when I peg it I'm also getting a faint, distant ringing almost like it's a reverb spring, but the amp doesn't have one. The guy I bought it from told me NOT to set the head on top of the cab. Of course I did the opposite. It looks cool, plus I don't have anywhere else to put it 'cept for the floor. And I'm not putting it on the floor. The 6L6's are original Bogen's. It only does this once in a while and only when it's pegged. The pre-amp tubes are pretty new he said. I want to switch to EL 34's and see if I need to change caps, resistors, etc. to park it in Plexi-Land permanently. Supposedly it's a Bassman circuit knock-off. 50 Watts.
Are the power tubes going?
if it is pegged it could be picking up rattling from the power tubes. you could also have a pre-amp tube going kind of wonky . . .
Microphonic preamp tubes, try swapping them around, if it get's noisier the 2nd preamp tube is going, if it gets quieter, it's the first. This assuming you know which is the first and which is the second.
Thanks Hemi, so I'll have to re-bias for the EL 34's when I switch. Is there anything else I need to know?
Plate voltage?
Quote from: Baltar on November 08, 2011, 04:36:07 PM
Thanks Hemi, so I'll have to re-bias for the EL 34's when I switch. Is there anything else I need to know?
Plate voltage?
isn't there some sort of pin-rewiring that has to happend for EL34s?
Different screen resistors, eh?
I use 1K 5W wirewounds for all tubes. Pin 1 on EL34s is grounded
Quote from: justinhedrick on November 08, 2011, 05:31:50 PM
Quote from: Baltar on November 08, 2011, 04:36:07 PM
Thanks Hemi, so I'll have to re-bias for the EL 34's when I switch. Is there anything else I need to know?
Plate voltage?
isn't there some sort of pin-rewiring that has to happend for EL34s?
Only if it's been oddly wired there's an internal connection on one that isn't on the other. Do you happen to know the B+ or plate voltage of the current circuit? Some can be swapped easily, as long as the bias voltage can be adjusted enough, some require more tweaking. For one thing an EL34 draws way more heater current than a 6L6 more than 50% more.
Are you up to sketching the power section? Measure B+ voltage on center of output transformer, all the values of screen resistors, etc. etc.?
Does it have a tube rectifier?
6L6 is 0.9A per tube, EL34s is ~1.5A per tube. Grid bias will need to be changed. Pin 1 grounded
Thanks guys, it's all tube. I'll try looking for what pre-amps are in it. I know fuck all about plate voltage and what not.
If schematics aren't your thing several places have layouts and wiring diagrams, more of a connect the dots idea.
(http://mhuss.com/SmallBox/50Wlayout.gif)
Awesome, there's a guy in town here that I might email about it. He lives like 5 mins from me.
Here's what's in my pre section:
6C4/EC90, 12AX7/EC83 & 6EU7
Interesting. The 6C4 is a 7 pin single triode, the other two are nine pin dual triodes. You'll be a triode stage short for a true plexi. You could make a 2 input version, instead of a 4 input, so saving a tube stage.
It just has 1 input in the back. I don't need this to be a matching numbers Plexi blah. I'd just like to get some 34's in there for more mids and a British sound. If a Bassman is supposedly close to a Plexi, then this can't be an imposible change.
(http://drtube.com/schematics/fender/bassman-5f6-a-schematic.gif)
(http://drtube.com/schematics/marshall/jtm45tr.gif)
Well Marshall went through a few iterations between their first 'bassman' clone and then the plexi, and what seems to get most people excited about them is doing the patch cord trick, where you jumper your guitar into both channels, so that it runs into two tube stages in parallel, one with a bright cap, both with their own volume, before being combined.
The only major differences though, seeing as the bassman also had two inputs, were, Marshalls had a Low and High input on each 'channel', they dropped the 12AY7 on the input for 12AX7's throughout, and dropped the rectifier tube in favour of a solid-state rectifier. Maybe Nick will weigh in on the topology of each gain stage.
But yeah, if you want to put 34's in there it will probably change the sound, just follow what Nick said.
Bassmans vs Plexi
Okay
Bassmans have more feedback as compared to some Plexi's which have 100k NFB resistors while the Bassman in that schematic has a 27k. Thats going to change the response of the power amp.
Bassman has 56k in the slope resistors versus the traditional 33k for a Plexi, more low mids for a Plexi, much rawer IMO
Having a 12ay7 will have less gain than a 12ax7. There are some versions of the Plexi which use the same shared cathode cap/resistor (820R//250u) or some can be split with the normal channel being 820R with a 250u and the bright has a 2.7k with a 680nF cap. On the Plexi's its much much brighter, there is a large bright cap on the bright channel of the resistive mixer circuit right before V2A and the resisitive mixers are larger 470k versus the 270k show in this schematic above. Virtually the same phase inverter but with slightly different coupling caps off the plate of the LTPI in Plexi's. You would have to source schematics to look at the different power supply filtering schemes.
Some plexis have a bypass cap on the 820 cathode resistor in V2A some dont
Another big difference is that many Plexi's do not have GZ34 tube rectos while this Bassman below has a tube recto. Going to really change the response of the amp. solid state recto give you more voltage and faster response while tube recto's lower voltage and give you seg.
Finally, that bassman below has 5881s which are a really stout version of a 6L6GC and Marshall's usually ran 34s for economic reasons, it was exspensive to import 6L6s from America to England. In response, England made the KT77s and the Kt66s.
I might crack it open later today and take some pics. Here's what I found online about the amp:
I bought this as a "broken" amp off eBay in November for $25. The circuit is sort of loosely based on the Princeton AA964.
Differences are:
No tremolo
No negative feedback
Bypassable extra gain stage in front (just plug in the other jack to bypass it)
6L6GCs instead of 6V6s
Slightly different tone stack values
weird old Bogen power section with voltage multiplier style rectifier
I finished this today and haven't had a chance to really give it a good work out, but I like it so far. It's very quiet, even with the extra gain stage engaged. I can crank the extra stage and then use my normal volume control as sort of a master volume for getting a nice lower level overdrive, and i can get nice cleans from it as well.
This was my first conversion and also my first time doing all point to point wiring and I really really enjoyed it.
Note: some of these components are vestigial from when this was a PA.
(http://i8.photobucket.com/albums/a47/bren1973/My%20rig/bogen-chb50-6.jpg)
according to that schematic u have negative feedback
rad, a bax stack 2
Uh.....? Good or bad?
Quote from: Baltar on November 09, 2011, 11:00:14 AM
Uh.....? Good or bad?
negative feedback. You can run it with or without it. Not required. Actually too much nfb can cause stablity issues.
Bax Stacks are fuckin awesome
So bottom line, I need to ground a pin on the plate, and re-bias for 34's and that's it?
Quote from: Baltar on November 09, 2011, 11:03:58 AM
So bottom line, I need to ground a pin on the plate, and re-bias for 34's and that's it?
yea ground pin 1, rebias.
Make sure as you play ur PT doesnt get to hot and the heaters draw too much VA. your drawing about 0.6A more per tube
The amp gets pretty warm already, it has a metal housing. Should I change the pre section or go with the same tubes?
Quote from: Baltar on November 09, 2011, 11:10:19 AM
The amp gets pretty warm already, it has a metal housing. Should I change the pre section or go with the same tubes?
Sort of stuck with the heat, if its being generated by the PT unless u swap that out.
Just to draw your attention to the fact, Nick said watch your power transformer doesn't get too warm, as it's supplying an extra amp and a quarter. Your whole amp may get warm, from the heat given off by the tubes, which is a normal thing. An overhot PT on the other hand, as in much warmer than the rest of the amp is what you want to watch for. It could end in xfmr failure :(
YUK!!!! I smoked my Sovtek's OT by flipping that stupid switch on the back. So to be safe, I would have to look into something from Mercury Mag?
no you dont need a Merc, just a PT setup for the heater pull. Any 50W JMP PT would work. I can get you them for less than a Merc
$100 Hammond, and a 68$ Magnetic Comp PT for a 50W JMP
Awesome, thanks for the info. I'm not in the market to do it right now. But at least I know the basics.
You can still plexify the rest of the circuit but keep the 6L6's, making the changes that were suggested would doubtless change the tone of the amp.
Also you can add an 'extra' xfmr, if chassis space allows, just for the tube heaters, rather than buying a replacement for the PT.
(http://www.surplussales.com/Images/Transformers/LowVoltage/tp-p-8648_lg.jpg) (http://www.surplussales.com/Transformers/HvLvTr-4.html)
$18 for a 4A 6V xfmr, thats 3A for two EL34's and .3A per triode, so that's 3.9A. Or you could just use it for the power tube heaters, and leave the other transformer supplying the heaters for the preamp tubes.
4A is a touch close to the limit, that tranny would be running at its VA limit
Well, I don't wanna tempt fate. I'd prolly go for a different PT. I mean the amp sounds damn close to a Plexi, but I'd really like to have 34's. I've never owned an amp w/ them in it.
Your safety margin is?
4A at 6V is 24W peak, so 3.9A at 6V (assuming no loading effects) is 23.4W. I mean you will probably cause the heaters to drop a little under such full load
I would follow Hemi's suggestions ur schematic shows an more uncommon recto setup which i cant quite make out but it is not the same as a normal marshall recto. Subbing a PT might require more work than you think
this heater pt from edcor is 27 bucks
http://www.edcorusa.com/products/925-lvp6_3-5-120.aspx
3.15-0-3.15 @ 5A with 120V primary
I'd say your over-cautious, given that I was using worst case scenario heater ratings, and Stancor is a reliable brand, if they say they can do 4A, I'll trust them at 3.9A. Still you're probably a habitual double-bagger, and that's OK ;)
Quote from: Hemisaurus on November 09, 2011, 03:14:56 PM
I'd say your over-cautious, given that I was using worst case scenario heater ratings, and Stancor is a reliable brand, if they say they can do 4A, I'll trust them at 3.9A. Still you're probably a habitual double-bagger, and that's OK ;)
double bag nah, i dont bother
call me a cautious engineer oh well i like to over design things, B+ only 375V?? Plates and Screen caps rated fro 1KV lol
I like to design, with budget and space in mind, as well. We don't all have limitless pocketbooks, or live at home with our folks. I'm the Toyota of amp engineering, the nasty foreigner that builds shit that lasts forever, that everyone loves to badmouth, but ends up buying anyways, because it works. Also I guess I build it in the US too ;D Maybe call me Hemiota from now on.
PS 375V makes you a B+ wuss ;D
Quote from: Hemisaurus on November 09, 2011, 03:22:54 PM
I like to design, with budget and space in mind, as well. We don't all have limitless pocketbooks, or live at home with our folks. I'm the Toyota of amp engineering, the nasty foreigner that builds shit that lasts forever, that everyone loves to badmouth, but ends up buying anyways, because it works. Also I guess I build it in the US too ;D Maybe call me Hemiota from now on.
PS 375V makes you a B+ wuss ;D
Not if your making jtm45 based power amp then 375 is about right under load
Just realised that makes you Cadillac, the US brand that started, in order to copy UK designs (RR) over here ;D
Quote from: Hemisaurus on November 09, 2011, 03:24:37 PM
Just realised that makes you Cadillac, the US brand that started, in order to copy UK designs (RR) over here ;D
i didnt realize u were from UK?
Quote from: dunwichamps on November 09, 2011, 03:28:24 PM
Quote from: Hemisaurus on November 09, 2011, 03:24:37 PM
Just realised that makes you Cadillac, the US brand that started, in order to copy UK designs (RR) over here ;D
i didnt realize u were from UK?
he's a damn scott.
Single T please, and no e in my whisky.
I meant to mention nick, I was reading about the Geloso 292-A amps, 100W from a pair of EL-34's, which is in spec if you read the datasheet, but they were running 1000V plate! 200V over the standard anode spec.
Also you were talking about running a Laney Super and a Dallas? How about building a Laney Klipp style, where Laney built a tube overdrive into the amp itself :)
(http://fkh.dk/laney/Laney001.jpg) (http://fkh.dk/laney/Laney001.jpg)
End of random tech banter, resume your normal programming. :)
Quote from: Hemisaurus on November 09, 2011, 03:37:22 PM
Single T please, and no e in my whisky.
I meant to mention nick, I was reading about the Geloso 292-A amps, 100W from a pair of EL-34's, which is in spec if you read the datasheet, but they were running 1000V plate! 200V over the standard anode spec.
Also you were talking about running a Laney Super and a Dallas? How about building a Laney Klipp style, where Laney built a tube overdrive into the amp itself :)
(http://fkh.dk/laney/Laney001.jpg) (http://fkh.dk/laney/Laney001.jpg)
End of random tech banter, resume your normal programming. :)
the klipp uses a differential amp to get that fuzz channel. Its kind of interesting and nice, Sound City has something similar in terms of an early stage differential amp. The B+ on the differential amp is very very low so it clips real easy, then you mix the clipped signal back into the main signal line, and boom OD channel
Could be built
The Stonehenge amp I am building is like a Supergroup which is more or less an SL but mine has some nice tweaks
My reason for a rangemaster + amp is for pure Iommi worship really
Like this shit
Clearly not wnorshipping hard enough. You're playing right handed and still have all your fingertips.
Just read the dumbest article. An amp builder bought a brand new Orange AD200B, played it and decides he can make it better. So he guts it, new pots, tube sockets, tagboard etc. and then he also replaces the xfmrs. Dude just spent over 2 grand for a chassis, headshell, panel and knobs. WTF was he smoking?
Quote from: Hemisaurus on November 09, 2011, 11:55:27 PM
Just read the dumbest article. An amp builder bought a brand new Orange AD200B, played it and decides he can make it better. So he guts it, new pots, tube sockets, tagboard etc. and then he also replaces the xfmrs. Dude just spent over 2 grand for a chassis, headshell, panel and knobs. WTF was he smoking?
at that cost why not just fuckin build your own 4xKT88 amp derp derp derp
Quote from: dunwichamps on November 09, 2011, 11:58:05 PM
Quote from: Hemisaurus on November 09, 2011, 11:55:27 PM
Just read the dumbest article. An amp builder bought a brand new Orange AD200B, played it and decides he can make it better. So he guts it, new pots, tube sockets, tagboard etc. and then he also replaces the xfmrs. Dude just spent over 2 grand for a chassis, headshell, panel and knobs. WTF was he smoking?
at that cost why not just fuckin build your own 4xKT88 amp derp derp derp
Electric did an overhaul exactly like that. I raise my eyebrow high and wonder why.
http://www.planetoftheamps.com/orange-ad-200-mk3-bassamp.html (http://www.planetoftheamps.com/orange-ad-200-mk3-bassamp.html)
Quote from: Ayek on November 11, 2011, 04:14:31 PM
Quote from: dunwichamps on November 09, 2011, 11:58:05 PM
Quote from: Hemisaurus on November 09, 2011, 11:55:27 PM
Just read the dumbest article. An amp builder bought a brand new Orange AD200B, played it and decides he can make it better. So he guts it, new pots, tube sockets, tagboard etc. and then he also replaces the xfmrs. Dude just spent over 2 grand for a chassis, headshell, panel and knobs. WTF was he smoking?
at that cost why not just fuckin build your own 4xKT88 amp derp derp derp
Electric did an overhaul exactly like that. I raise my eyebrow high and wonder why.
http://www.planetoftheamps.com/orange-ad-200-mk3-bassamp.html (http://www.planetoftheamps.com/orange-ad-200-mk3-bassamp.html)
Pretty sure the Electric guy doesn't have the option of just ordering a Matamp like most people could. Pretty sure I know what Jeff would call him if he tried.
Pretty sure that was repaired, by MacNeece, for a customer. Pretty sure they kept one of the original xfmrs. Pretty sure the amp was broken.
All information regarding that amp was in the link. Said it was sent in for repair... $1500 later and it works good
^no shit, it better spit flames too.
there ya go dunwich, make an amp that spits fucking fire!
Wait, I'm pretty sure they already do.
I already got a 200W amp coming out soon, 4 x KT88 using some custom trannies.
Is not technical >:(
I was on holiday 'til I get an email that someone needs tech help.
Sunn, can we move that to a Dunwich Appreciation thread ;)
Quote from: Hemisaurus on November 23, 2011, 05:51:37 PM
Is not technical >:(
I was on holiday 'til I get an email that someone needs tech help.
Sunn, can we move that to a Dunwich Appreciation thread ;)
sorry for the mishief just delete, no need for an appresh thread for me
So I'm beginning to source parts for a 200W 4xKT88 amp. What do you amp types recommend for a standby switch? Is there such a thing as a 1000VDC/1A toggle switch? Do I need to go that high? Would your garden variety Carling do the job?
dont switch the DC switch the AC secondary, then get anything rated for 120V/250V for more than a few amps. Secondary current is small, under an amp
i want to run two different 'pedal style' synths w/ fx and a theremin through a dod resistance mixer and into a single amp. can i dump that much current safely through that set up without having problems..??
*serious question..im tech challenged for the most part..
I'm not entirely sure what current you are worrying about? The currents involved in instrument output are pretty negligible.
A line level unit is made to drive into about 10KOhms input resistance at about 1V which if you grab Ohm's Law
V=IR
1=R*10,000
R=0.0001 (100 uA)
A guitar is even less it's a few hundred millivolts into a 1MOhm resistance.
Plus you are loading down each output with the resistance mixer, so I wouldn't worry about current.
Perhaps you should throw down the basic math behind certain things we deal with, Hemi.
???
I think Sunn means the ohms law triangle an such
V
I R
Volts (V) = Current (I) x Resistance (R)
Current (I) = Voltage (V) / Resistance (R)
Resistance (R) = Voltage (V) / Current (I)
You add power (P) to the equation
Power (P) = V x I
P = I2 x R
Quote from: Hemisaurus on December 01, 2011, 08:43:05 AM
I'm not entirely sure what current you are worrying about? The currents involved in instrument output are pretty negligible.
A line level unit is made to drive into about 10KOhms input resistance at about 1V which if you grab Ohm's Law
V=IR
1=R*10,000
R=0.0001 (100 uA)
A guitar is even less it's a few hundred millivolts into a 1MOhm resistance.
Plus you are loading down each output with the resistance mixer, so I wouldn't worry about current.
ok..maybe current wasnt what i meant..what im trying to say , is having two synths cranked up going through the mixer and into a single amp going to be too much 'juice' or whatever term is correct, for the amp to handle with out having problems..is there a point where too much signal from these devices is too much..??
Your resistance mixer should effectively limit your juice, should you have too much
Ah, well I stated Ohm's Law already, then substituted in, algebra people ;)
It's very difficult to overload an input section, to the point of physical / electrical damage, unless you do something silly like connect a speaker out of an amp to an input. Connecting multiple line level or instrument level signals together, should be OK, especially, like Ayek said, if you are doing it via a resistive mixer.
Early PA's, were often little more than a resistive mixer connected into a tube amp.
(http://i8.photobucket.com/albums/a47/bren1973/My%20rig/ScreamingTree003.jpg)
(http://i8.photobucket.com/albums/a47/bren1973/My%20rig/ScreamingTree002.jpg)
(http://i8.photobucket.com/albums/a47/bren1973/My%20rig/ScreamingTree001.jpg)
(http://i8.photobucket.com/albums/a47/bren1973/My%20rig/ScreamingTree004.jpg)
So I need help with my Screaming Tree, I can't read a schematic so forget that. I tried running it into a 3dpt, which I have. I know this is a simple circuit. I did have it hooked up before, but I was running it through the battery killswitch and it boosted. I also did have it running throught the 3pdt, but it actually got quieter when I stepped on it. Can anyone help? I love this pedal and it was a gift. I can post more pics or a video if need be.
(http://www.generalguitargadgets.com/diagrams/switch_lo_3pdt_ig_battery.gif)
You need to figure out your input and output wires, the input should be running to a capacitor, the output will be coming from the pot.
Wire it up as per the diagram. Can I get a shot of the front? It looks like you have a switch and a pot and an indicator?
Oh hang on, Screaming Tree, not Screaming Bird??
Similar rules apply, figure out your input and output, and wire up the switch according to the diagram, get it working without the switch first, is probably easiest, then you know your in and your out. I'll scratch about for a schematic for my benefit.
OK, it's the same unit, with a kill switch? Odd.
That looks like a stereo jack on the input, I'd wire it according to the GG diagram, battery clip ground to input jack ring, sleeve ground to rest of circuit, and not bother with the battery switch.
The cap connected to the orange wire, should be the input cap, one end of it should connect to just the input jack, the other to one end of two resistors and the transistor.
The other cap connects to the top of the pot, the center of that is your output, (black wire).
(http://www.generalguitargadgets.com/richardo/perfboard/bird.gif)
resistors are the squiggles they are prefixed R
capacitors are the parallel lines they are prefixed C
transistor is the one marked Q1
input jack is J1 output jack is J2
where the lines connect is where the connections are.
Buggery, I just broke a leg off at the transistor. Clean off, I need a new tranny now and it says:
2N5952 on it. Not what most schems say on the Tree. It's A LOT different sounding than the Bird, really, really nasty.
(http://i8.photobucket.com/albums/a47/bren1973/My%20rig/ScreamingTreetranny.jpg)
(http://i8.photobucket.com/albums/a47/bren1973/My%20rig/ScreamingTree2002.jpg)
(http://i8.photobucket.com/albums/a47/bren1973/My%20rig/ScreamingTree2001.jpg)
(http://i8.photobucket.com/albums/a47/bren1973/My%20rig/ScreamingTree2003.jpg)
yeah that won't help ;)
get a NPN transistor from the shack. you can buy an individual NPN 2n3904 for $1.19 or a bag of 15 mixed NPN for $2.99, any of those will do the job for you.
Quote from: Hemisaurus on December 06, 2011, 05:46:56 PM
yeah that won't help ;)
get a NPN transistor from the shack. you can buy an individual NPN 2n3904 for $1.19 or a bag of 15 mixed NPN for $2.99, any of those will do the job for you.
I'm heading back to Detroit this weekend, we don't have the Shack in Canada, we have Sayal's. I really want to get the 2N5952, I don't want this pedal to sound different. I want it to hurt people, clear rooms and start dogs barking. Will the 2N3904 sound different?
I got into a similar discussion with a bunch of geeks on another board and we concluded the differences between transistors with the same part name is as big as the difference between tranistors with different part names.
Avast and belay that last comment, a 2N5952 is a FET, not an NPN transistor atall, so yes it would sound radically different, it would be the wrong part. Which is odd, because these things weren't originally built with FET's, but if you have a FET in yours and like the sound, keep going with a FET.
Thanks for the info, I'll lay out the whole damn thing, ID the resistors so we both know what's going where, nab a 2n5952, and figure it out Monday. I'll probably stop at Sayal's on the way out of town to save some gas and see if they have 'em.
EDIT: I'll grab a 2N3904 too, it might be something else in the circuit that makes it so nasty. Maybe a resistor? Should I nab a socket too, so I can swap them out?
Err, see changed previous comment ;)
Ok, weird eh? I told ya, it's a Fairchild tranny.
Well Sayal's do NTE's, the corresponding part is NTE312 the Sayal SKU is 148677
Cool thanks again bro!
Grab a socket if you feel confident about soldering it into place, you'll have to be very careful swapping transistors though as the socket will be in free air, don't stress the connections when you so that.
Gotcha, I'll give it a shot! To be continued on Monday.
For all those wondering where the bright cap is on your gain pot, it is the silver mica cap (brownish) sticking out from the 2 lugs on the pot in the middle of this shot
(https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/374954_10150601290104552_403563559551_12019387_1421534099_n.jpg)
load up paint and draw a red circle around it, lazy bugger ;)
I'm putting up pics of my Bogen's guts tonight, maybe you guys can tell me some easy mods.
Not sure if this is a valid question, but I'll ask anyway.
When lowering or raising pick ups, can the process affect intonation of the guitar, and thus needing a set up?
Quote from: johnny problem on December 11, 2011, 09:55:35 PM
Not sure if this is a valid question, but I'll ask anyway.
When lowering or raising pick ups, can the process affect intonation of the guitar, and thus needing a set up?
If the magnets are effecting the natural elliptical motion of the string, it may pull it out of tune a wee bit. Lower the pickup a little bit. The guitar ~just~ may need a setup.
Probably should ask Jake to do a guitar tech thread, but no, intonation is a product of string tension and length, adjusting picup height affects neither.
Thank you!
Can anybody hook me up with a step by step on how to wire a cab that can double for bass/guitar and let me know what tools I'll need? (Sorry, I'm totally inexperienced but I should learn how to do this)
I'm thinking a 2X12 & 4 ohms that can pull double duty will work for me.
From google search I can see the speakers I'm looking at are 8 ohms and would have to be wired in parallel
Here's what I'm looking at...
http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail (http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail)
http://www.carvinguitars.com/products/single.php?product=PS12-8 (http://www.carvinguitars.com/products/single.php?product=PS12-8)
Should I be looking into any of these extra options stagecraft offers?
http://www.stagecraftgear.com/servlet/the-Options/Categories (http://www.stagecraftgear.com/servlet/the-Options/Categories)
Here's the heads I use:
Sunn Beta Bass
Sunn Concert Bass (Red)
Sunn Coliseum Bass (Silver)
GK 700RBII
Acoustic 370
The 370 & Coli being the most powerful. Do you guys forsee any problems with what I've chosen and these heads? Also the cab is open back, not sure how much that will matter for playing bass since I've never tried one before. There is an option to make the cab switchable from open/closed though.
Many thanks in advance.
Quote from: grimniggzy on December 22, 2011, 11:47:23 AM
Can anybody hook me up with a step by step on how to wire a cab that can double for bass/guitar and let me know what tools I'll need? (Sorry, I'm totally inexperienced but I should learn how to do this)
I'm thinking a 2X12 & 4 ohms that can pull double duty will work for me.
From google search I can see the speakers I'm looking at are 8 ohms and would have to be wired in parallel
Here's what I'm looking at...
http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail (http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail)
http://www.carvinguitars.com/products/single.php?product=PS12-8 (http://www.carvinguitars.com/products/single.php?product=PS12-8)
Should I be looking into any of these extra options stagecraft offers?
http://www.stagecraftgear.com/servlet/the-Options/Categories (http://www.stagecraftgear.com/servlet/the-Options/Categories)
Here's the heads I use:
Sunn Beta Bass
Sunn Concert Bass (Red)
Sunn Coliseum Bass (Silver)
GK 700RBII
Acoustic 370
The 370 & Coli being the most powerful. Do you guys forsee any problems with what I've chosen and these heads? Also the cab is open back, not sure how much that will matter for playing bass since I've never tried one before. There is an option to make the cab switchable from open/closed though.
Many thanks in advance.
nothing special in wiring. ohms are ohms. i would worry abou thte open back cab though.
Quote from: justinhedrick on December 22, 2011, 12:07:15 PM
Quote from: grimniggzy on December 22, 2011, 11:47:23 AM
Can anybody hook me up with a step by step on how to wire a cab that can double for bass/guitar and let me know what tools I'll need? (Sorry, I'm totally inexperienced but I should learn how to do this)
I'm thinking a 2X12 & 4 ohms that can pull double duty will work for me.
From google search I can see the speakers I'm looking at are 8 ohms and would have to be wired in parallel
Here's what I'm looking at...
http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail (http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail)
http://www.carvinguitars.com/products/single.php?product=PS12-8 (http://www.carvinguitars.com/products/single.php?product=PS12-8)
Should I be looking into any of these extra options stagecraft offers?
http://www.stagecraftgear.com/servlet/the-Options/Categories (http://www.stagecraftgear.com/servlet/the-Options/Categories)
Here's the heads I use:
Sunn Beta Bass
Sunn Concert Bass (Red)
Sunn Coliseum Bass (Silver)
GK 700RBII
Acoustic 370
The 370 & Coli being the most powerful. Do you guys forsee any problems with what I've chosen and these heads? Also the cab is open back, not sure how much that will matter for playing bass since I've never tried one before. There is an option to make the cab switchable from open/closed though.
Many thanks in advance.
nothing special in wiring. ohms are ohms. i would worry abou thte open back cab though.
Noted. I'll probably opt for the open/closed option its only $25 extra.
So the first diagram on \/ this \/ page would be me right?
http://www.colomar.com/Shavano/2x12wiring.html (http://www.colomar.com/Shavano/2x12wiring.html)
Quote from: grimniggzy on December 22, 2011, 12:11:48 PM
Quote from: justinhedrick on December 22, 2011, 12:07:15 PM
Quote from: grimniggzy on December 22, 2011, 11:47:23 AM
Can anybody hook me up with a step by step on how to wire a cab that can double for bass/guitar and let me know what tools I'll need? (Sorry, I'm totally inexperienced but I should learn how to do this)
I'm thinking a 2X12 & 4 ohms that can pull double duty will work for me.
From google search I can see the speakers I'm looking at are 8 ohms and would have to be wired in parallel
Here's what I'm looking at...
http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail (http://www.stagecraftgear.com/servlet/the-30/Blues-Jack-212-%E2%80%93/Detail)
http://www.carvinguitars.com/products/single.php?product=PS12-8 (http://www.carvinguitars.com/products/single.php?product=PS12-8)
Should I be looking into any of these extra options stagecraft offers?
http://www.stagecraftgear.com/servlet/the-Options/Categories (http://www.stagecraftgear.com/servlet/the-Options/Categories)
Here's the heads I use:
Sunn Beta Bass
Sunn Concert Bass (Red)
Sunn Coliseum Bass (Silver)
GK 700RBII
Acoustic 370
The 370 & Coli being the most powerful. Do you guys forsee any problems with what I've chosen and these heads? Also the cab is open back, not sure how much that will matter for playing bass since I've never tried one before. There is an option to make the cab switchable from open/closed though.
Many thanks in advance.
nothing special in wiring. ohms are ohms. i would worry abou thte open back cab though.
Noted. I'll probably opt for the open/closed option its only $25 extra.
So the first diagram on \/ this \/ page would be me right?
http://www.colomar.com/Shavano/2x12wiring.html (http://www.colomar.com/Shavano/2x12wiring.html)
yepps.
mucho appreciatto mi amigo
now all i need is the money, uggh :'(
Quote from: grimniggzy on December 22, 2011, 12:43:08 PM
now all i need is the money, uggh :'(
i know what you mean! i just got a bonus check at work today, and it is already spent paying off the wife's credit card.
i could have bought an AWESOME cab with it.
My bonus this year went straight into savings. Dis nigga needs a car, don't even know why I'm looking at cabs.
I'm seeing 212's for $100 and under at the musicgoround, sure they ain't as pretty as the one you want, but I bet they make noise, and they look deeper than the one you had linked, better bass response ;)
(http://mgrinventory.s3.amazonaws.com/small/eoEjmNyYnUSzT2NIcFcmRg.jpg)(http://mgrinventory.s3.amazonaws.com/small/vVwiOh6pyESn9pyKEvE5MQ.jpg)
http://musicgoround.com/search.aspx?q=212+cab&cid=8&scid=0&sid=0&d=10&c=10&ob=6&p=2 (http://musicgoround.com/search.aspx?q=212+cab&cid=8&scid=0&sid=0&d=10&c=10&ob=6&p=2)
Yeah, I should look into used stuff before I make a purchase.
Quote from: grimniggzy on December 22, 2011, 02:14:11 PM
Yeah, I should look into used stuff before I make a purchase.
good idea. plus, on that music go round website that hemi linked to there is a 2x12 "steel sound" bass cab for $100 in louisville, ky.
I'd be wary putting the 370 to 2 12's... it's kinda scary with 15s...
Go back to school, and write out 100 times It's not the size, it's the handling.
I have 10"s that handle 200W, 12"s that handle 400W and 15"s that handle 150W.
I still like the 15"s though, for spreading the power through four of them :)
Quote from: Hemisaurus on December 22, 2011, 11:09:06 PM
Go back to school, and write out 100 times It's not the size, it's the handling.
I have 10"s that handle 200W, 12"s that handle 400W and 15"s that handle 150W.
I still like the 15"s though, for spreading the power through four of them :)
yeah yeah yeah, but it still feels wonky to me putting so much power to two 12s...
I've always thought it's weird using 10" speakers on bass and 12"s on guitar, so there you go.
Me too, i think Ampeg started it, and I imagine it was a compromise so that they could fit 8 drivers into a reasonably sized cabinet. I think when the SVT first arrived, they needed all 8 drivers to handle 300W, just a theory.
I still think 15"s are the way to go, personally. ;)
Quote from: SunnO))) on December 22, 2011, 11:11:42 PM
Quote from: Hemisaurus on December 22, 2011, 11:09:06 PM
Go back to school, and write out 100 times It's not the size, it's the handling.
I have 10"s that handle 200W, 12"s that handle 400W and 15"s that handle 150W.
I still like the 15"s though, for spreading the power through four of them :)
yeah yeah yeah, but it still feels wonky to me putting so much power to two 12s...
Yeah, I'd probably just use the Beta or C.Bass to run a 2X12. The 370 through 15's is mighty impressive.
Quote from: Hemisaurus on December 22, 2011, 11:39:21 PM
Me too, i think Ampeg started it, and I imagine it was a compromise so that they could fit 8 drivers into a reasonably sized cabinet. I think when the SVT first arrived, they needed all 8 drivers to handle 300W, just a theory.
I still think 15"s are the way to go, personally. ;)
Needed 16, the SVT was supposed to run two cabs for full tilt. They were basically guitar drivers anyway. Speaker diameter hasn't go much bearing on things, especially if you have multiples in a box.
Actually, what I find even weirder than 10" speakers for bass is the bass cabinets with tweeters in 'em. Why? It's bass for fuck's sake. Some bass cabs are even running 8"s, I bet they all got tweeters in there, too. I guess it must work, but it still weirds me out.
Quote from: Ayek on December 28, 2011, 06:56:08 AM
Actually, what I find even weirder than 10" speakers for bass is the bass cabinets with tweeters in 'em. Why? It's bass for fuck's sake. Some bass cabs are even running 8"s, I bet they all got tweeters in there, too. I guess it must work, but it still weirds me out.
One word "slap". That's the style of bass playing and what bass players who use tweeters need. ;D
Quote from: moose23 on December 28, 2011, 07:41:43 AM
Quote from: Ayek on December 28, 2011, 06:56:08 AM
Actually, what I find even weirder than 10" speakers for bass is the bass cabinets with tweeters in 'em. Why? It's bass for fuck's sake. Some bass cabs are even running 8"s, I bet they all got tweeters in there, too. I guess it must work, but it still weirds me out.
One word "slap". That's the style of bass playing and what bass players who use tweeters need. ;D
Unless you're that guy from Korn -shudder-
Quote from: SunnO))) on December 28, 2011, 10:52:57 AM
Quote from: moose23 on December 28, 2011, 07:41:43 AM
Quote from: Ayek on December 28, 2011, 06:56:08 AM
Actually, what I find even weirder than 10" speakers for bass is the bass cabinets with tweeters in 'em. Why? It's bass for fuck's sake. Some bass cabs are even running 8"s, I bet they all got tweeters in there, too. I guess it must work, but it still weirds me out.
One word "slap". That's the style of bass playing and what bass players who use tweeters need. ;D
Unless you're that guy from Korn -shudder-
He needs a slap too.
So really nerdy amp question here. I want to build an amp with parallel channels, like a tweed Bassman or a Marshall 1987/1959, with the channels jumpered and each channel voiced differently. If I want to blend those channels, can I just put them on a 1Meg dual-ganged linear pot, and where would said pot go? If I place the pot before the coupling cap(s), I get DC on the pot and a scratchy pot. If I put the pot after the caps (where the volume pots traditionally go), would the coupling caps create phase problems? What if they're different sizes (say .022 and .068)? I could just use a post-phase inverter master to control volume, rather than individual channel volumes. Thanks!
dont worry about phase problems. not important.
why the fuck is something as simple as getting a good 9v neg center adaptor so complicated..theres a million different sizes..wattages, amps..wtf.
i dont understand how there is not some sort of industry standard going on here..
One spot.
Things to look for are current capacity, and is it regulated.
Current capacity is obvious, do you have enough current to power all the pedals?
Regulation, is where the voltage is kept at 9 volts, no matter what the current drawn (unless you go over the rating). A lot of pedals are unregulated, they may be 9V at 500mA but if your pedal only draws 200mA, they may be up at 13 or 14 volts :o This can harm sensitive pedals, but is harmless to most.
so having said that..how many mAs do i need..how do you know..
It's often printed on the pedal, else guesstimate about 300mA per.
if you are in the ballpark of that number will my device be ok..?? by ballpark i mean + or - 400mA
You can never have too much current/mA on your power supply only too little as each pedal will only draw as much current as it needs. Me I'd only buy 500mA and over regulated supplies but even that's overkill for the seven pedals I run which I'd guess add up to under 200mA with my Boss DD3 being the biggest at 45-60mA.
Probably. Most pedals take a little overvoltage.
I have a Boss pedal that only works with a Boss adaptor I assume bevause it needs 9.6V to run, I imagine they stuck a protection diode in on the power jack, and my regulated 9V supply is too low for it.
Quote from: moose23 on January 17, 2012, 08:50:34 AM
You can never have too much current/mA on your power supply only too little as each pedal will only draw as much current as it needs. Me I'd only buy 500mA and over regulated supplies but even that's overkill for the seven pedals I run which I'd guess add up to under 200mA with my Boss DD3 being the biggest at 45-60mA.
The problem with too much current capability is on
unregulated supplies, having over the spec'd 9V when they are not fully loaded down.
A 1.5A regulator can be built, for the nervous, from a 7809 regulator and a couple of caps, see the 7809 spec sheet. ;)
(http://newportretail.com/images/guitaraccessories/NW1CP2-one-spot-combo-pack.JPG)
would this work..
i could power everything with that..
Most likely. You haven't said what you are powering though.
i am powering 3 synths..the infection 2 and 3 as well as the dementia synth..also a few standard guitar fx pedals that i run the synths through..boss and dod pedals..
(http://www.noisefx.com/images/products/m_audiblediseaseinfectionin3_4345.jpg)
(http://www.noisefx.com/images/products/m_audiblediseasedementiadm1_4628.jpg)
(http://www.noisefx.com/images/products/m_audiblediseaseinfectionin2_0744.jpg)
The synth's if properly built should hopefully have a nice big resevoir capacitor and maybe protection diodes on the power input, and probably would be just as happy running of 12V as 9, so I imagine your safe. The Boss pedals, if they are analog, I imagine you'll be OK, if they are digital, it was a half analog, half digital Boss pedal I had the problems with using a bog standard 9V adaptor, so be warned, and the DOD will require the funky mini-jack (2.5mm or 3.5mm I forget) earplug style, rather than a Boss style, looks like a couple are included in your hairy harry kit.
According to Visual Sound, they're 1-Spot will handle 1700mA so that should be plenty, but those synth's might be big drinkers, so if you have problems, try adding one pedal at a time to the chain, until things start to go wrong, start with the guitar pedals I guess ;D
Or you could email Audible Disease and ask them the power requirements of their synths.
would i be better off just getting individual power supplies for each synth..??
fuck the pedals..i can just keep sticking batteries in them if need be..although it would be nice to have everything run off one or two power supplies.
thanks for the advice..
Quote from: mortlock on January 18, 2012, 11:29:25 PM
would i be better off just getting individual power supplies for each synth..??
fuck the pedals..i can just keep sticking batteries in them if need be..although it would be nice to have everything run off one or two power supplies.
thanks for the advice..
In the long run one of these would be cheaper than batteries. http://www.voodoolab.com/pedalpower_2.htm
I have a Extention cord/ reg. power supply on the drawing board.
Erik, Weber do a xfmr for that, though it's not a toroid, 8 individual. 11V AC 300mA windings and a 9V AC 2A winding for your Alesis gear ;D
Mortlock, I'd try it and see, see how much you can run from one wart first.
(https://taweber.powweb.com/store/wpdlxfmr2sch.jpg)
Yep. I'm going to use one of the weber trannies. I got into a discussion about pedal power with my brother. He wants batteries, saying there is never an outlet for pedals. Which got me thinking....
There's a couple of options there. There's the rechargeable pedal power block (is that Voodoo), there's some company makes a Li-on battery back with a DC-DC converter to power 9V pedals (it was in a Tape-Op), you could also grab a couple of 6V wet cells or gel cells and make your own.
With a rechargeable block, you need to figure out a cigar lighter attachment charger, for charging it in the van between shows. ;D
solar cells + DC/DC converter hahaha j/k
Green Power!
(http://www.greenamps.com/greenamp6x12-cab-gzamp.jpg)
My car charger is green, the car runs on corn.
How can there be power for amps and no power for pedals?
I run a power supply into a power plug on the back of my board. Plug one 18' extension cord onto the back of my board and everything's powered up. Way easier than when I used to mess around with a bunch of batteries.
Quote from: fallen on January 24, 2012, 01:12:02 AM
How can there be power for amps and no power for pedals?
I run a power supply into a power plug on the back of my board. Plug one 18' extension cord onto the back of my board and everything's powered up. Way easier than when I used to mess around with a bunch of batteries.
That was my thought. While a rechargeable pedal power is interesting, I was thinking of a power strip/extension cord/power supply. Easy enough to do and eliminates ground loops from different circuits.
Anyone got a source for impedance plugs like this:
(http://hiwatt.org/images/VSelWith.jpg)
Pretty sure I'm going to have to make some, since I've got about half as many as I need. Making sure there isn't somewhere I can jsut get them. Anyone want any if I do?
Looking for a book or a link to download this book. I owned this book but was lost in one of my moves - it's still in a box along with my copy of Radiotron Designer's handbook volume 4.
I can't remember the author or the title of the book, but it's was shall I say "different".
Here are the details the author was Australian and was a huge fan of Tektronic "Our father who art in Beaverton". He may of even worked for them. This book was all about designing the "perfect" tube preamp. The preamp was fully differential and used 6dj8 tubes in a cascode circuit with jfet's (i think) as a constant current source for the tubes. (Totem pole design?)
Alot of the book was about his journey as a tube circuit designer, he had very "odd" ideas. It had lots of theory but put in a easy way to understand - very little mafs IIRC.
Way long shot - I bought this book back in 94 or 95 off of Compuserve or Usenet posts. It came as a flimsy photo copy and was about $35 plus shipping! But the info was AWESOME.
Aha!
Typing out that request jogged the last remaining brain cells I have left.
I figured out the book and author.
Author: Allen Wright
Book: The Tube Preamp Cookbook
I guess he died last year. Couldn't find a copy to download tho.
Ill search for yas, E.
Need a recommendation on a cheap but good oscilloscope. I had a Tek 456, but that is gone with the ex. ???
Edit:
This one is really close to my house and seems like a good deal.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170775374000&ssPageName=ADME:X:RTQ:US:1123
I'm in proper need of a tube tester and an O-scope, myself. Lookin' for that book, by the way. Had a few leads on it.
EDIT: no downloads available.
Quote from: SunnO))) on February 03, 2012, 07:37:37 PM
I'm in proper need of a tube tester and an O-scope, myself. Lookin' for that book, by the way. Had a few leads on it.
EDIT: no downloads available.
Yea I searched but only found fake links.
Never liked the 2212 myself, it always felt kind of cheap, the trace never seemed to focus enough.
Erik, do you happen to have an audio generator that sweeps? I'd trade you a nice HP scope for one. The one with the DMM built in on the top
(http://dub.greboguru.org/oscope.jpg)
Quote from: Hemisaurus on February 08, 2012, 08:54:07 AM
Never liked the 2212 myself, it always felt kind of cheap, the trace never seemed to focus enough.
Erik, do you happen to have an audio generator that sweeps? I'd trade you a nice HP scope for one. The one with the DMM built in on the top
Oh I do. An old HP tube job. I have to get it down from my storage loft in my office.
It's a HP 200ABR (Tho is says 200AB it's the rack mounted version. 4U)
(http://i402.photobucket.com/albums/pp108/foxhunter351/Things%20I%20once%20had/HEWLETTPACKARD200ABRAUDIOOSCILLATOR.jpg) (The 1/4" jack is a mod in this pic)
It hasn't been turned on for years and I currently don't have a variac...
We should organise a little jaunt to Bloomington. It's about midway, and we can trade, I think shipping might be a bitch. You can meet the little guy, and we can have pizza or Flat-Top or something.
Quote from: Hemisaurus on February 08, 2012, 03:25:53 PM
We should organise a little jaunt to Bloomington. It's about midway, and we can trade, I think shipping might be a bitch. You can meet the little guy, and we can have pizza or Flat-Top or something.
take him to avanti's.
http://chicagostylepizzeria.com/ (http://chicagostylepizzeria.com/) would be where I'd go. It's odd, because I never saw a pizza like this anywhere in Chicago.
Quote from: Hemisaurus on February 08, 2012, 05:41:22 PM
http://chicagostylepizzeria.com/ (http://chicagostylepizzeria.com/) would be where I'd go. It's odd, because I never saw a pizza like this anywhere in Chicago.
LOL is that an Atkin's Diet Pizza?
The meet up would have to be on a weekend...
My cell number is on my Email me page on my site.
Can anyone tell me what this noise is at :46? It sounds like a static/white noise when I turn the master volume to 6 or more.
Nope, Invalid Youtube Link ::)
ruh oh... Sounds ground-y....
I'd have someone look at it, in the real world ;)
Erik, that metal plug with the external ground pin scared me a lot, I put on a shiny orange plastic one instead ;D
It was good as the rubber in the cable was rotting too.
A shot in the dark, but do lights with dimmers contribute to amp noise/hum? The room my half stack is in has lights with dimmers.
Yes they do, as do fluorescents, cell phones, TV's (not too sure about plasma and LED ones), microwaves, fridges, washers, heaters, vacuums. Anthing that puts noise on the power line, or electromagnetic radiation in the air. Dimmers are in the former category, the thyristor firing in bursts, will introduce noise on the power line, they probable generate some EM as well. That's why the PA bible, and I think some amp install manals like Crown's, say always keep your stuff on a separate circuit, and well away from.
Quote from: Hemisaurus on February 13, 2012, 12:08:13 AM
I'd have someone look at it, in the real world ;)
Erik, that metal plug with the external ground pin scared me a lot, I put on a shiny orange plastic one instead ;D
It was good as the rubber in the cable was rotting too.
Yea I forgot about that plug. Hey man it was the 50's.
Yeah, no big issue, but then I noticed it's worn and cracked at the grommet end as well, so I'm just going to see if I can add a new cable, got plenty of nice orange 3 core hanging around here.
Quote from: Hemisaurus on February 13, 2012, 03:24:07 PM
Yeah, no big issue, but then I noticed it's worn and cracked at the grommet end as well, so I'm just going to see if I can add a new cable, got plenty of nice orange 3 core hanging around here.
more importanty, did you get the pizza?!
Quote from: justinhedrick on February 13, 2012, 04:26:27 PM
more importanty, did you get the pizza?!
No, we went to flat top grill. MY GF is Gluten free, plus that pizza sounds WEIRD.
What's the scoop on using a mix of kt88s and 6L6s in an amp. Eurotubes have it as an option for 5150s. Think its possible in a Butcher?
Well the output sections are very similar, the xfmr have different part numbers though, so it's not a straight copy. The KT's use almost twice as much heater current as a 6L6 though, so it would depend on the capability of their power xfmr. Having recently tried to get transformer info from Peavey, I've discovered it's one thing they won't talk about, which surprised me as they are generally pretty helpful.
I'd email the Eurotubes guy, he seems to have one of every amp in the universe, and would probably be willing to experiment for you ;D
KT88's can get 100W out of a pair, but have similar plate load and grid bias requirements as the 6L6 doing 55W, so I guess the idea should work, as long as the heater supply can handle it.
Quote from: Hemisaurus on February 24, 2012, 06:37:13 AM
Well the output sections are very similar, the xfmr have different part numbers though, so it's not a straight copy. The KT's use almost twice as much heater current as a 6L6 though, so it would depend on the capability of their power xfmr. Having recently tried to get transformer info from Peavey, I've discovered it's one thing they won't talk about, which surprised me as they are generally pretty helpful.
I'd email the Eurotubes guy, he seems to have one of every amp in the universe, and would probably be willing to experiment for you ;D
KT88's can get 100W out of a pair, but have similar plate load and grid bias requirements as the 6L6 doing 55W, so I guess the idea should work, as long as the heater supply can handle it.
you may need additional bias setup since bias voltage will be different
I thought that, then I looked at the datasheet. In the 500V plate range, which is where the Butcher and the 5150/6505 live, they (KT88 and 6L6) are actually both very similar. Hence I imagine Eurotubes selling them as 'without bias mod' sets. I imagine he just matches them up as a quad.
i have heard he matches them by plate current. the only other concern is spacing, do you have adequate space between the sockets for Kt88s
I believe that's why it's a mixed set of the 5150, as there's not the space to do a full KT-88 transplant, hence me suggesting he ask the guy at Eurotubes ;)
I believe there would be room if its a mixed quad. Would tonal differences be worth it I wonder.
All your really doing is mixing in two tubes that won't break up, as they have way more headroom with two that will, if you push them hard. I suppose it could be worth doing if you only run one amp, and need a bit more of that clean sound blended in. Though you could try doing some kind of blend in the preamp too. If you run two amps, turn the gain down on one a bit and make it cleaner, and work from that.
to be honest the last thing i would say that is problematic with adding in KT88s is that your grid leaks are way out of spec for this setup
most 6l6 amps with 4 tubes probably use 220k grid leaks on both sides. A single Kt88 is rated for a maximum of 100k grid leak (including grid stop resistor) so you are nearly 5 times larger than the recommended spec for Kt88s. The problem with using a oversized grid leak is that when you really get the amp ripping, your going possibly go into runaway bias problems due to large grid leakage of KT88s. the grid leakage current will cause a voltage drop across the grid leaks and this will increase the bias voltage under heavy load and this is a positive feedback mechanism, once u go to far you will lead to runaway red platting at large volumes.
He's not pushing them nearly hard enough for that to be an issue, look at the voltages on the schematic.
Is it do-able? yes, if the power supply can handle the increased heater current, and there is enough physical space in the unit, and the KT's are matched well with the 6L6's.
Is it worth doing? who knows.
Quote from: Hemisaurus on February 24, 2012, 07:11:22 PM
He's not pushing them nearly hard enough for that to be an issue, look at the voltages on the schematic.
Is it do-able? yes, if the power supply can handle the increased heater current, and there is enough physical space in the unit, and the KT's are matched well with the 6L6's.
Is it worth doing? who knows.
I disagree, if you plan on slamming it hard running it really loud using grid leaks that large is problematic.
Build it, prove it ;D
Whoa. I'll take it! Lemme know if you want someone to prototype it with a band... ;D ;D ;D
Is there some magic secret to tuning low and having low action without tons of tone killing fret buzz that I am not aware of aside from using thick strings, proper truss rod adjustment, and not using a cheap guitar with uneven frets? Some recent news just made my year much more expensive so I'm probably going to end up buying a pretty cheap new guitar instead of a fairly cheap new guitar. I would guess that a more expensive axe would be less likely to need a fretjob. It's like you pay one way or the other no matter what. I like to use the B to B strings from a 7 string set for A tuning. A bit floppy but not ridiculously so although the neck has to be just right or the action has to be mega high like it is on my Epi paul jr that I don't want to put anymore money into.
I think this is one for Sunn ;D
From my experience, thick strings for good tension, well adjusted truss are the key. There is the whole string length thing, which you could apply to guitar as well as bass, where the total length of string is key for tension. So say you had an instrument where the bridge and the saddles were separate, ie. most Gibson styles with stopbar tailpiece, moving the tailpiece further from the saddles would give you more string length, better tension, whilst keeping the same scale.
(http://dub.greboguru.org/gibsonsg.jpg)
So something more like this would be a downtuning monster, as you have all that extra string length, whilst the saddle to nut distance is the same, so the tuning is not affected. I think Erik (inductorguitars) and I discuss it earlier on in this thread.
Just a thought ;D
See this thread. (http://riffrocklives.com/forum/index.php?topic=4161.msg105018#msg105018)
You're not going to get ~quality~ if you skimp, I'll tell you now.
http://www.rondomusic.com/product4669.html (http://www.rondomusic.com/product4669.html)
^^^buy one of these
http://www.rondomusic.com/al2000blackflm.html (http://www.rondomusic.com/al2000blackflm.html)
or one of these^^^
(http://ep.yimg.com/ca/I/juststrings_2196_91677578)
put these on it^^^^
Proper truss rod adjustment = a very small amount of relief. Hell, since I've started doing my own fretwork, I've been setting my necks DEAD STRAIGHT. Even frets will do wonders for your action. Some guitars ~just~ play like shit, though.
Using B To B of a 7 string set is still a really small set, considering. 56-11ish for lights? Those Baritone strings are made for extended scale guitars, so the tension isn't an issue. Use the new string end to file the nut so it seats evenly in the bottom, then play for a while. I usually drop the action as low as it goes, with buzz. Then raise it until it stops, on my guitars. Customers, I usually have a set value to put shit at. You can look for lifting frets, uneven wear etc etc. There's a lot to look at.
I like how they list a bunch of random specs in those Agile/Rondo ads, but at least in the LP Special copy, they don't list the scale length. I assume it's 24.7" like the Agile SX2000. And all those exclamation points! Why use periods!
That Callisto looks sweet, though. I've heard good things about those guitars being worth every penny and then some.
Quote from: Hemisaurus on February 28, 2012, 07:58:55 AM
(http://dub.greboguru.org/gibsonsg.jpg)
This picture just blew my mind.
Quote from: Hemisaurus on February 28, 2012, 07:58:55 AM
I think this is one for Sunn ;D
From my experience, thick strings for good tension, well adjusted truss are the key. There is the whole string length thing, which you could apply to guitar as well as bass, where the total length of string is key for tension. So say you had an instrument where the bridge and the saddles were separate, ie. most Gibson styles with stopbar tailpiece, moving the tailpiece further from the saddles would give you more string length, better tension, whilst keeping the same scale.
(http://dub.greboguru.org/gibsonsg.jpg)
So something more like this would be a downtuning monster, as you have all that extra string length, whilst the saddle to nut distance is the same, so the tuning is not affected. I think Erik (inductorguitars) and I discuss it earlier on in this thread.
Just a thought ;D
Something tells me standard-length guitar strings are not gonna cut it. Does anyone make extra-long strings? I also have to imagine all that string behind the saddle is gonna create tuning problems.
Those baritone strings I posted would work. Baritones are 28-30", so, those strings are what you'd need.
You think? For a 3 + 3, it's only maybe an extra 4"? Don't have an SG by to measure, but you could adjust the tailpiece distance to fit regular strings, how long is a regular string?
I'm thinking I must have a fret or two that is too high.
That is one interesting SG there.
I'm still thinking about getting an Ibanez RG for a bit more scale length.
Are those Callistos for $140 actually decent guitars? That's a great price. I like those Agiles but would prefer something less than 10 lbs. Sometimes my mid-weight guitars piss off a nerve or something in my shoulder and I have to stop playing or sit down and put the guitar on my leg.
The Set neck callistos can be made into great players.
Quote from: RacerX on February 28, 2012, 06:32:34 PM
I also have to imagine all that string behind the saddle is gonna create tuning problems.
I thought so too before, but it's actually less. It takes more stretching to bend - if you do lots of 1.5 step bends like Gilmour it might not be a good fit.
Quote from: SunnO))) on February 29, 2012, 01:39:37 AM
The Set neck callistos can be made into great players.
Thanks for the info dude. I will keep these in mind.
Quote from: inductorguitars on February 29, 2012, 11:37:14 AM
Quote from: RacerX on February 28, 2012, 06:32:34 PM
I also have to imagine all that string behind the saddle is gonna create tuning problems.
It takes more stretching to bend
I don't do a lot of bends but I don't like this idea. Less work is better when playing.
Quote from: SunnO))) on February 29, 2012, 01:39:37 AM
The Set neck callistos can be made into great players.
It's too bad those juniors all have P90s. Humbucker size P90s would make them more versatile. I want more gain.
Going to jam on my buddy's RG through my Laney this weekend and see how that goes.
Quote from: liquidsmoke on March 01, 2012, 02:38:27 AM
Quote from: SunnO))) on February 29, 2012, 01:39:37 AM
The Set neck callistos can be made into great players.
It's too bad those juniors all have P90s. Humbucker size P90s would make them more versatile. I want more gain.
Going to jam on my buddy's RG through my Laney this weekend and see how that goes.
Ibanez = Ibenhad. Fuck those things. Firewood.
Quote from: SunnO))) on March 01, 2012, 01:10:21 PM
Ibanez = Ibenhad. Fuck those things. Firewood.
Too thin sounding? What don't you like about them? I would get a fixed bridge model, I have no need for a floyd.
What do you think about Schecters? I like the looks of the Omen model.
I just tuned up to B from A, it destroys with metal power. I'm staying in B.
There's a huge range of quality with Ibanez going back over three decades
I just don't like them, ugly headstocks, too light, thin necks, meh meh meh.
Have you played one of the "lawsuit" models from the 70's? You know, the ones that were nearly identical to the Gibsons of the day?
Quote from: Metal and Beer on March 01, 2012, 03:50:55 PM
Have you played one of the "lawsuit" models from the 70's? You know, the ones that were nearly identical to the Gibsons of the day?
Well, yeah, but I'm not counting those as Ibanez. Those aren't the guitars that everyone associates with Ibanez. These are:
(http://www.ibanezregister.com/images/images-jems/IbanezJEM777SK1.jpg)
(http://www.markeaston.org/miscimages/rg350m.jpg)
(http://www.alkalifewater.com.my/PICS/comp/neon.jpg)
Unfinished scalloped fretboard says it all.
They also come in black..
I like thin necks but my wrists are pretty weak/still somewhat fucked up. One in mahogany would probably treat me right although I do think they look kind of blah.
Quote from: SunnO))) on March 01, 2012, 01:10:21 PM
Quote from: liquidsmoke on March 01, 2012, 02:38:27 AM
Quote from: SunnO))) on February 29, 2012, 01:39:37 AM
The Set neck callistos can be made into great players.
It's too bad those juniors all have P90s. Humbucker size P90s would make them more versatile. I want more gain.
Going to jam on my buddy's RG through my Laney this weekend and see how that goes.
Ibanez = Ibenhad. Fuck those things. Firewood.
I have to disagree. While nothing is quite an SG I've owned 2 ibanez's. I had a custom S series that was incredible and I have just the regular black ibanez and it does everything that I want it to
Keep my Ibanez away from yo fire! >:(
(http://s140.photobucket.com/albums/r5/mbiebes/?action-view¤t=HPIM0101-1.jpg)
I'm getting this figured out. What I want in a new axe-
mahogany body
no more than 8 pounds
2 passive pups
4 knobs
black
not neck heavy
half way decent quality all around
no more than $300
One of these in black would probably do the trick if it could take regular size pups- http://www.rondomusic.com/callistojrnat.html
http://www.rondomusic.com/al2000black.html (http://www.rondomusic.com/al2000black.html)
two pounds isn't gonna hurt ya.
I'm using a fairly wide padded strap now and that's going okay with my junior but I'm not sure how it would go with that beast.
All black, I prefer the dots(because I suck), and with a good setup and electronics upgrades and fret job if needed this would do it-
http://www.epiphone.com/Products/Les-Paul/Les-Paul-Studio.aspx
If Gtr'd Center has one of these in black tomorrow morning that plays well I'll probably pick it up. You all have until about 9am central time to talk me out of it. Me wanting this guitar has nothing to do with it saying Epiphone on the headstock. It's about the light weight, dots, and looks over the probably higher quality Agile. I am confident that if I don't get a lemon it can be made to play and sound perfect.
Meh, do what you want. You asked, we answered. If it ends up sucking, lesson learned. The Agile will have way better QC, and overall better quality. So. Do what you will.
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I don't doubt you. If I get the Epi and it sucks I'll return it.
True.
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And if it doesn't suck it's going to a pro for the works and eventually I'll have recordings of it for yall to hear.
$297 plus tax. Currently in E and it shakes the fucking house. B is going to destroy. To me this is a real Les Paul. I should have bought one of these 10 years ago!
Cool!
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Have it in B now with a 13-59 set. Sounds like Victor Pentagram meets the heaviest power metal imaginable through my Laney GH50 with no pedals. It took 5 or 10 minutes for me just to get used to the blasting thick tone, it seemed like overkill at first. The neck is thicker than I would like but I respect it and it's fine because the sound is so heavy. Fucking devastating. Les Pauls rule, even this cheap one that was MADE IN CHINA. This is it. If I become financially well off in the future I'm buying the heaviest vintage Gibson LP(or maybe a top tier Agile) I can find and I'll lift more weights if need be so I can play it without shoulder pain.
I'm not even sure this thing needs new pups, the stocks ones sound amazing at the moment and the frets seem very level. I'll try to lower the action a bit soon and see how that goes.
Oh also, the neck is set, not a bolt on like I previously thought. Probably helps somewhat.
drop it all the way to the frets, then raise it until it stops buzzing. Just like the pros.
Will do.
Thinking about ordering these for my Epi LP, am I crazy?
http://www.guitarfetish.com/GFS-Power-Rails-Crushing-power-Killer-Tone-Black-on-Black_c_106.html
I would of course keep the mid and treble knobs turned down as much as need be to avoid ice picky tone.
if i had a p bass or a j bass with the pickups wired into one volume..and wanted to eliminate the tone control knob..how do you make sure the tone is what you want it to be?? i mean without the tone knob to set it..what is it naturally..am i making sense?? i want my bass to be set at the full bass setting..how do i make sure my bass is set at that when the tone knob is removed..
When you say full bass do you mean tone knob rolled all the way back? If so you need to replace the pot with a equal value resistor.
If it's full on then no need to replace it with anything.
Eh? don't you mean for tone at 0 replace with a capacitor, for tone at 10 don't?
The tone is just a bleed to ground via a cap. At zero the cap is effectively across the vol control, at 10 it's in series with the full tone pot resistance.
If your worried about tone control, don't yank it. If you never touch the tone control, just yank it.
(http://www.guitar-mod.com/wiring/pbass.gif)
Quote from: Hemisaurus on March 08, 2012, 08:10:00 AM
Eh? don't you mean for tone at 0 replace with a capacitor, for tone at 10 don't?
The tone is just a bleed to ground via a cap. At zero the cap is effectively across the vol control, at 10 it's in series with the full tone pot resistance.
If your worried about tone control, don't yank it. If you never touch the tone control, just yank it.
(http://www.guitar-mod.com/wiring/pbass.gif)
Eh yeah that's exactly what I meant. Dunno what I was thinking there.
Where's my kilt fuzz?
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Quote from: SunnO))) on March 13, 2012, 06:44:59 PM
Where's my kilt fuzz?
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what?
Sorry never got round to tracing it out, you want a gutshot instead?
Oh yeah, that was the problem, I put mounting tape on the back of the PCB couldn't see what I'd done :-[
Bugger.
;D
^^^^^^^^^^^^^^^^
The Emperor's New Fuzz?
My all generic killer fuzz, generic as in you can get every part from the local rat shack (I think). Sunn is turreting it up, look for it soon from HemiSunn enterprises ;D
Quote from: RacerX on March 16, 2012, 05:22:12 PM
^^^^^^^^^^^^^^^^
The Emperor's New Fuzz?
I can, er, see it. Honest.
Oops, didn't get the reference :-[
Yo guys, whassup with the SX Guitars on Rondo's site?
If I bought \/ this \/ would I have to replace everything?
http://www.rondomusic.com/callistojrnat.html (http://www.rondomusic.com/callistojrnat.html)
Any other suggestions? I'm trying to do this guitar shit on the cheap considering how much $$$ I spent on bass gear in the past.
I had a SX once. The main issue was the tuners sucked - not smooth at all. Other than that it was ok.
buy it, play it, decide, any opinion on here is probably made by an asshole ;)
My Peavey vibrated a tube out of it's socket. I didnt notice a difference in tone. Hahahaha. Anyways. New sockets or a proper retensioning?
How does that happen?
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Enough panel resonance in the cab to vibrate the head that much says there is a problem with the cab. Is there a spring retainer or screening can missing?
Beats me, Oli. The retainers are weak, and the sockets have little/no grab left in 'em. Should I get some of those fancy tube retainers?
Or just put new sockets in?
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http://swartamps.com/tech/socket_retention/ (http://swartamps.com/tech/socket_retention/)
Damn iPad lost my first reply >:(
It's up to you, you should be retensioning the socket, when you give the amp a service, but replacing the socket will have the same effect.
Fancy tube retainer, do you mean a can? Is it a preamp tube? Either way it's not unheard of to shake a tube loose, but I'd retension or replace all the sockets, not just the one. I've never replaced a socket for lack of tension personally, only when someone has mangled the pin holders or the socket has arc'd.
I did retension when I first got it. I think they're just shot. I'll do it again, just as a final straw thing, and if they're too lose... I'll just replace 'em.
Ya still didn't say which tube :)
Amps that hang the tubes upside down, you are better having some kind of retainer (obvious). Metal cans are there to screen preamp tubes, and dampen microphonics, as well as providing physical support. Bear claws on power tubes, don't survive well on the whole, you can look at fitting spring retainers if needs be.
Power tubes, sorrY. Hanging upside down tubes.
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Yeah, then I'd probably want to have some kind of physical retainer, either some new and snug gripping bear claws, or a spring retainer, I wouldn't just rely on the gripping tension of the pins :-[
Gratuitous pic to demonstrate spring retainers follows ;)
(http://upload.wikimedia.org/wikipedia/commons/thumb/7/79/Kt88_power_tubes_in_traynor_yba200_amplifier.jpg/800px-Kt88_power_tubes_in_traynor_yba200_amplifier.jpg)
what does it mean when i turn my amp on and all i get is a loud hum..nothing works..did i fry the shit out of it at a recent gig like i think i may have??
Could be. What kind of amp, what kind of hum, did you check the outlet it's plugged into and the cables it's connected with?
its a peavey bandit and i just tried to run 2 synths at once at extreme volume at my last show..i think i popped it about 6 seconds in..
Well, if you've got hum, then you didn't blow the speaker, unless the transformer is humming.
Have you tried all the inputs, including the FX return? Do you hear noises when turning the knobs? Any signs of life?
(http://muzix.narod.ru/schemes/ampl/bandit65.jpg)
i tried all inputs..no sounds at all except the loud hum. nothing seems to work..no knobs, no switches..
So it makes exactly the same hum, same volume, same tone, no matter what knobs you turn or buttons you press?
yes..that is correct..non responsive except a loud hum when amp is turned on..
Well if none of the tone controls affect it, and none of the inputs produce any sound, then your problem is in the power amp section. The fact that there's a loud hum, means the power transistors are still alive, or at least one of them is, if you had an O/C or S/C the cone would pop when you turned it on, and then no further noise.
Are you planning to try and fix it yourself? It's the sort of job that would be really easy with an oscilloscope, you'd just backtrack from the output and see where the hum stopped. Without one, I guess you could try and probe it and listen for clicks. It's only 43V so it won't kill you, like a tube amp might, as long as you stay away from the power transformers connection to the mains.
That's me assuming of course it's a Bandit 65, and reading from that schematic, maybe it's not, maybe it's some other model which has a higher DC supply voltage.
fixing it myself is out of the question. way out of my league..is it even worth fixing..i only paid a hundred bucks for the amp to begin with..
Err, so what was the technical question ???
the question is what the heck did i do to my amp..??
what is the lowest power rating amp i can get away with using for the 2 to 3 syths i pump through it..i cant afford to keep blowing amps up.
the bandit was an 80 watt amp..and i fried it right out of the gate..
I think there's sort of a misconception here. The power rating of the amp does not dictate what input it can handle. You may have forced the amp to blow up by driving it too hard, but you can connect the synths to any amp, just don't turn everything up to 11.
For the frequency range of a synth, lots of low frequencies and square waves, a bass amp might be the way to go.
i told you i was a fucking moron when it comes to this shit.
I guess with synths it makes it difficult to spot the nasty buzzy farty sounds of your amp reaching destruction, from the nasty buzzy farty sounds of your synth ;)
So bass amp, don't go beyond 7, 'til you're sure it's safe :)
thats what i needed..thanks.
Question: My verellen has kind of a weak clean channel. It stays clean but doesn't have a great deal of volume on tap. When I want to use pedals, I find that I have to crank the effect's output, use most of the preamp volume, and then bump the master up to ~2 o'clock. If I have too much bass or output (say from a clean boost after a fuzz) the amp gets glitchy and then massive volume drop??? Usually dropping the volume and toggling from clean to crunch fixes it. Still, it's always done this and it's making me want to get something else or swap preamp tubes to clean up the crunch channel and use it for pedals.
I've never worked on a Verellen, but I wouldn't imagine it's meant to be that way. I'd contact Verellen, or failng that, your local qualified amp tech. Even if it is functioning as designed, handwired amps are easy to modify. You say it's always done this, have you ever had the preamp tubes changed?
Yeah, back in '09. I had a bad preamp tube that was causing all kinds of popping and arcing.
It only seems to happen on the rare occasions when I drive the amp hard, but not harder than would be expected of a 100 watt amp.
I'd suspect a bad pre tube again. You could try swapping around the pre tubes, or just replacing them.
You can send it to me at:
Mumumbo Tinigard
1384 Kalishnikov Way
Clickclick, Nigeria 656-655
I will deposit three thousand monies into your bank account upon arrival
Sent from my DROID X2 using Tapatalk
Alright, I'll look into that. Prolly just swap the whole set because Ben mentioned something about a bad batch of preamp tubes when he looked at it in '09. I think he just swapped the single offender that time.
I put my new 16 ohm speakers in my 2x12 and took it in to have it wired properly because I didn't want to fuck it up(okay I'm a loser, even though I'm planning on tearing half my motorcycle apart and putting it back together and riding it 70-80+ mph). I told them to wire it parallel for 8 ohms. I get it home and this is what I see-
a black and a white wire from the jack to speaker 1
a black and a white wire from speaker 1 to speaker 2
That's it. Is this correct? I don't want to burn up my amp.
I thought there was supposed to be a wire connecting the + wire that goes from the jack to speaker 1 to the positive terminal on speaker 2, or something funky like that as this overly simplistic diagram shows-
http://www.eminence.com/support/wiring-diagrams/
The thing is that each speaker has 4 metal tabs for wires to attach. This is why I didn't try this myself, it just confused the shit out of me.
Grrr...
So two wires from the jack to speaker 1, and two wires from speaker 1 to speaker 2, sounds right.
For parallel you connect jack > + on Speaker 1 > + on Speaker 2
sleeve of jack > - on Speaker 1 > - on Speaker 2
so sounds right.
The 4 tabs are just so you can parallel up connections, there's only a plus and a minus and the tabs are in an L on each
(http://www.soundwavesmm.com/Cab%20(12).JPG)
You can see the positive terminals marked on the left here.
So why do these diagrams I see online show a wire going from the wire before speaker 1 connecting to speaker 2?
(http://www.eminence.com/wp-content/uploads/2010/12/wiringparallel2.gif)
It doesn't matter where you connect it, you could join the wires together, but it's easier in a lot of cases just connecting the wires together on one of the speakers using the 4 tabs, the two tabs either side are connected together it's like a jumper cable, you follow?
Excellent! Got cha. I'm going to crank the shit out of these fuckers right now.
And thanks!
To my ears the Swamp Thangs sound almost exactly the same as the Governors only they don't break up like crazy at high volumes. A O K.
This is fifties guitar wiring? Correct?
(http://i.imgur.com/dvWbc.jpg?1)
P.S. I did not pay for those Gibson bumblebee cap fakes but feel sorry for whatever guy did. ;D
Forgive me if this has been discussed in this (or other) threads before, but I'm wondering if you pros could help me with what might be a fairly simple DIY project.
I was considering making footswitchable volume knob pedal between my guitar and amp. I want to do this because there's a very small sweet spot when I back off of my guitar's volume knob into my overdriven amps, and it's really hard to roll back to it on the fly when I want to clean up the signal.
Would it be as simple as wiring a potentiometer and a switch to a pair of 1/4" jacks in a housing? Please say yes.
Something like this, but $40 or so cheaper: http://www.ebay.com/itm/The-Leech-Passive-Volume-Attenuator-Guitar-Pedal-with-LED-/330720454606?pt=UK_Guitar_Accessories&hash=item4d0079a7ce#ht_1019wt_1224
Pretty much, what you said. Wire it like the volume knob in your guitar, it'll be passive, but it'll do what you want it to do.
Are there any do's and don'ts to consider? Is any type of switch better than another? What resistance pot should I use? How many licks to get to the center of a Tootsie Pop?
You'll want a 3PDT if you want to add an LED indicator, and then you'll also need to add a battery and a resistor to limit the LED current.
http://www.generalguitargadgets.com/faq/40-technical-questions/180-many-bypass-switching-options (http://www.generalguitargadgets.com/faq/40-technical-questions/180-many-bypass-switching-options)
have all the links you need.
Also be aware you are putting this in parallel with your guitar volume control,. it will change the tone, it will move the sweet spot. If you don't want that to happen get some of those no-load pots for your guitar, which are out of circuit when they are turned up full.
Others who know better should prob pipe in, but if this is a foot-controlled passive volume pedal, you should be able to use the same pot as in your guitar. So 500K for humbuckers, 250K for singles is common wisdom. As far as switches, a DPDT switch will give you true bypass. If you really want to get fancy, use a DP3T switch for an LED, but that'll require a battery. Your average mono non-switching jacks should work too. Stereo input jack with the battery negative connected to the ring terminal will disconnect the battery when the pedal is unplugged, if you go the LED/3PDT/battery route. I'd wire the pot exactly like it is wired in your guitar, since you're cloning your volume knob and just making it switchable. If you need parts numbers, I could get those for you.
One...two-who...thrrree...(crunch)...three.
So basically, what Hemi said.
Quote from: SoupKitchen on May 03, 2012, 11:39:38 PM
Others who know better should prob pipe in, but if this is a foot-controlled passive volume pedal, you should be able to use the same pot as in your guitar. So 500K for humbuckers, 250K for singles is common wisdom. As far as switches, a DPDT switch will give you true bypass. If you really want to get fancy, use a DP3T switch for an LED, but that'll require a battery. Your average mono non-switching jacks should work too. Stereo input jack with the battery negative connected to the ring terminal will disconnect the battery when the pedal is unplugged, if you go the LED/3PDT/battery route. I'd wire the pot exactly like it is wired in your guitar, since you're cloning your volume knob and just making it switchable. If you need parts numbers, I could get those for you.
One...two-who...thrrree...(crunch)...three.
So basically, what Hemi said.
That is only true if the pots in the guitar are taken out of circuit. Otheriwse his 500K in his guitar is now in parallel with 500K in the pedal, yielding 250K. Hence either:
1. Deal with it, find the new sweet spot
2. Fit no-load pots to the guitar
3. Fit push/pull pots and wire it so they can be switched out of circuit
4. Fit double the value you need in the pedal and guitar so, 1M in the guitar and 1M in the pedal gives you 500K
5. Just wire past the pots in the guitar, do all the work with the pedal.
There may be other options too. ;)
I'll take Door #1.
If that's the case, the Ernie Ball passive is 250K I think. There used to be a Behringer one for about $25 too.
Simpler still, if there's space on your guitar, or if you fit a switched pot. Add a couple of fixed resistors, or a trimpot under the scratchpate, that you can switch to, to get the sweetspot, no enclosure, jacks, or extra cable necessary. No need to use your foot.
i just bought a sunn beta lead off ebay and it has a few issues.
the master volume doesn´t react after 3 and the amp is very quiet.
if i plug into both channels it basically beeps uncontrolably and the input jacks seem too tight ??? and they scratch.
some of the pots seem too loose and some too hard to turn.
is there an easy fix for these problems or will i have to consult a technician? (i have little to zero experience with repairing amps.)
Beeping sounds bad, sounds like the channel switching logic is messing up.
If you are using monster cable, that may explain your jack problem.
You probably will need to take it to be fixed, if your tech needs it, I have the full service manual, it's probably online somewhere too.
Yep it's here, http://sunn.ampage.org/site/svcmans/beta/ (http://sunn.ampage.org/site/svcmans/beta/) you may want to check the troubleshooting flowchart.
Err, nevermind the flowchart, incomprehensible :-\
thanks for the quick answer.
i opened it up to look for anything that was burned and found out that one of the input jacks is a bit corroded. i can´t see any bad solderjoints or any other visibly broken parts though.
it wasn´t cheap anyway and now i have to pump more money into it >:( if i can even find someone in my area to fix it.
I baby my Betas. They are far from quiet. Both max out volumewise at 4ish. I never even use that much.
Well any tech worth their salt, equipped with the service manual especially should be able to fix it. It is however an awkward beast, there's not many amps use switching logic, even less of that vintage. The logic control circuit is explained, clearly, at the start of the manual, if the IC's on your's are socketed it will make it easier, but I suspect they won't be.
I've often thought it might be easier to pull out all the complicated channel switching and fit a channel switcher module to one, if channel switching is still desired. :-\
Looking at the schematic to remind myself, I think it might be possible to jack channel 1 by lifting the end of R130 and connecting it to pin 6 of IC107, and removing Q104, that way you just removed the channel switch from the circuit. Likewise on channel 2 the end of C124, could be connected to pin 2 of IC108 and Q106 removed.
That way at least Channel A input and Channel B input should work, and you could control channel switching with an A/B pedal instead.
I only mention this in case you have a tech friend, you could save the parts and put it back together again, if / when you decided to / got the cash, etc.
Hey Nick, want to check my work ;)
What do you guys think of these?
http://www.ebay.com/itm/1950s-Military-Tube-Amplifier-15-Watts-Fantastic-Guitar-Harp-Amp-Tone-/150810837881?pt=LH_DefaultDomain_0&hash=item231d06c379
I can't imagine coming across 150 of them. He probably bought all of them for $150...
Not a technical question, it's soliciting an opinion, go directly to jail, Sunn will delete your post, then your account, then your life ;D
Also remember with military equipment, the military didn't care who they killed, including their own operators ;D
Quote from: Hemisaurus on May 10, 2012, 10:54:02 AM
Not a technical question, it's soliciting an opinion, go directly to jail, Sunn will delete your post, then your account, then your life ;D
Also remember with military equipment, the military didn't care who they killed, including their own operators ;D
Dang, I debated posting a new topic vs here. Guess I chose wrong.
My apologies.
Technically speaking, I'd be asking, was it designed to be mains powered. That tube compliment doesn't suggest the old suicide boxes with heaters in series BUT what does the army need a mains powered tiny amp for?
12AX7 is common enough 6AQ5 you might be best getting someone to change the tube socket from a 7pin Noval to an 8pin octal and allowing you to fit a 6V6.
For $250 I'd shy away, for $30 in a rummage sale or mil surplus deal, I'd go for it. Just think to yourself what tube amp can I buy for $250, designed for guitar already, brand new, warrantied, safety passed etc.
http://www.musiciansfriend.com/tube-amplifiers#fT=2012:100.00-200.00|200.00-300.00&gP=1&pS=20&v=g&sB=pLH&lP=c&catId=site1HAH (http://www.musiciansfriend.com/tube-amplifiers#fT=2012:100.00-200.00%7C200.00-300.00&gP=1&pS=20&v=g&sB=pLH&lP=c&catId=site1HAH)
http://www.musiciansfriend.com/tube-amplifier-heads#fT=2012:100.00-200.00|200.00-300.00&gP=1&pS=20&v=g&sB=pLH&lP=c&catId=site1HAMD (http://www.musiciansfriend.com/tube-amplifier-heads#fT=2012:100.00-200.00%7C200.00-300.00&gP=1&pS=20&v=g&sB=pLH&lP=c&catId=site1HAMD)
or send me $250, a friend of mine is selling a weird tube amp and a tester, you can have the amp Zenith amplifier and the tube compliment is: 12ax7, 6BQ5, 6BQ5, and a 5Y3 rectifier;D
I've got a ABY/phase question for you fellers. After reading this article, I thought that it might be wise to potentially add a mini toggle to be able to flip the phase if needed when running amps in stereo.
http://www.premierguitar.com/Magazine/Issue/2010/Apr/Getting_Back_In_Phase.aspx
My question is this: Could I simply add a mini toggle that that lives right at one of the outputs that can change the whether the +/– goes to the ring or tip of the jack? Does that make sense? Would it work? Is something like that going to introduce any unwanted "gremlins" into the signal? Also, Conan, what is best in life?
(http://i84.photobucket.com/albums/k32/jakeh_02/ABY.jpg)
You would have to change all the jacks to insulated type, the problem with just flipping one of the inputs or outputs would be you might inadvertently ground something you didn't mean to.
I love those articles written by idiots that don't know the difference between phase and polarity, having all your speakers moving in the same direction is good, but that's not phase.
Oddly the safest place to flip speaker polarity is at the speaker, make a little box that reverses the polarity at the speaker, or just make a reversed speaker cable and mark it accordingly.
After you've done all this, go back and remember high school physics on wave theory and realise the difference between the speakers is just as critical. If you're speakers are a half wavelength apart, then they are out of phase, and will cancel each other out, then realise your wavelength varies with the frequency ie. note you are playing, so there is always going to be points where your speakers are out of phase, and then just before your head explodes, realise that means that at some points your out of polarity amps are in phase.
BOOM!
i wouldnt recommend doing a phase flipping that way since ur not doing an active phase flip. What you can do instead is use a unity inverting gain stage, unity means gain of 1 or no gain but make the freq response flat so you get 180 phase flip on the one output
And I would not use the word polarity when referring to AC, phase is a more useful term. Polarity has more context when talking about electric fields or magnetic dipole alignment
Quote from: dunwichamps on May 10, 2012, 04:46:24 PM
i wouldnt recommend doing a phase flipping that way since ur not doing an active phase flip. What you can do instead is use a unity inverting gain stage, unity means gain of 1 or no gain but make the freq response flat so you get 180 phase flip on the one output
And I would not use the word polarity when referring to AC, phase is a more useful term. Polarity has more context when talking about electric fields or magnetic dipole alignment
Then you should read http://community.calrec.com/?p=1325 (http://community.calrec.com/?p=1325)
when we discuss things in the lab, 180 degrees phase difference is not called polarity. Polarity is usually referred when we discuss DC measurements but if its an AC waveform its phase. Phase is frequency dependent and is useful when discussing the electrical phase of the waveform hitting the speakers and the resultant sound waveform's relative phase is a different subject due to environmental influences of position/reflections, ect ect
Excellent. I think I'm hearing you gentlemen loud and clear and you're telling me to put down the soldering iron and buy one of these.
(http://www.chicagomusicexchange.com/product_images/m/719/RadialBones_Twin_City_-_ABY_Amp_Switcher_1___63834_zoom.jpg)
yea that will work. Hemi and I have this discussion each time this topic is brought up. Engineering death match
The article surmises that since a time shift is not evident then it should be called polarity to avoid confusion with the term phase which can mean time delay correlating to a phase shift
No worries. I saw a preview of it in the comment section of the article.
Yeah, your using the same term for two different things. Him flipping the signal ground to positive and positive to ground is a polarity switch, you should call it this as there is the possibility of a power component involved, ie. you can short out the output of a pedal, guitar or ground an amp the wrong way. The premier guitar article, and I agree, that the safe place to do this is at the speaker, not at the input.
Your inverting unity buffer is a phase shift, the signal is delayed, not just inverted. Inverting in a buffer is safe.
I will however reserve the right to laugh a lot if you paid big money for 'true bypass' pedals and then put that Radial buffer in your signal chain ;D
If you use isolation transformers in your ABY you can flip the signal by changing the leads of the secondary of the iso-tranny or you could do it by simply using a unity gain buffer or not using a unity gain buffer
Transformer, also phase reversal ;)
Haven't seen a high impedance matcher anywhere convenient, got a link?
Quote from: Hemisaurus on May 10, 2012, 05:34:44 PM
Transformer, also phase reversal ;)
Haven't seen a high impedance matcher anywhere convenient, got a link?
No i dont but BYOC has some op amp driven 1:1s in their design that work
Those little $3 RadioShack audio ones are 1K:8 if memory serves, two of them would work for isolating a line level, but not a guitar level just too low.
you could drive it to line level then reduce it to guitar level, kind of stupid u know but would work
A couple of passive DI transformers back to back, Jensen spec theirs as 200K:1.5K be cheaper buying a couple of cheap passive DI's and tearing them apart probably.
Something tells me we're overthinking this, as it's not gonna happen
yup. but thats engineering for you.
Quote from: Hemisaurus on May 10, 2012, 05:22:59 PM
I will however reserve the right to laugh a lot if you paid big money for 'true bypass' pedals and then put that Radial buffer in your signal chain ;D
I do use true bypass pedals as in, I truly bypass using pedals and plug straight into my amplifiers.
The pedals I do have are for shits and/or giggles.
1st Gen Model T blowing a fuse in a gnarly fashion. Its blowing the 47 ohm resistor from pin 2 on power tube. Any ideas?
(http://i15.photobucket.com/albums/a394/rzaray/IMAG0400.jpg)
pin 2 is heaters. That shouldnt be there I assume
Fuse blowing could be a short, or a blown cap or an arcing sockets
Why would there be a resistor on the heater? That would be weird.
According to the schemo, the 47ohm resistor is on pin 3, which is the plate, so I'd suspect a bad tube, sorry :'(
(http://music-electronics-forum.com/attachments/17516d1330316081-modelt.gif) (http://music-electronics-forum.com/attachments/17516d1330316081-modelt.gif)
Click for bigger.
bad tube, and I did mean "shouldnt"
only time I've seen a resistor on the heaters is to drop the voltage on those old suicide series heater tube amps ;D
owchy :o
yea that is dumb....but oh well
It's pin 3.
I didn't think a bad tube would do that kind of damage.
if you say shorted the tube ud be dropping 500V across 47 ohm resistor eeecckkk...
5000W ;D
is it possible to fuck up a modular synth by patching in shit the wrong way..is there a wrong way??
All the control voltages on the synth will be at the same level, unless it's using modules from different manufacturers in the same frame, then there is a slight risk. The danger is in patching in external eqpt, that may be at a different ground reference, or have a different CV range.
Hey fellas. I'm a new guy. Haze me if you must. I have JCM 800 2205 with an FX loop. I forget the year off the top of my head but I think it's around 1986. Brief history: a long time ago the volume would slowly fade out and it would just make a quiet fizzle when I played. Took it to some guys and thought I just needed some new tubes. I was just a young buck and I don't know if they screwed me or not, but they kept it for a long time and ended up saying the output transfer fried the caps and all sorts of shit and they ended up replacing all sorts of stuff (without permission).
It worked for a long time and still does. However, I've noticed funny things happen when I use the FX loop. Sometimes the volume will do the fade thing, but that's rare. I noticed it tended to happen when I would change the state of the loop (meaning I would start using it or stop using it). I ended up cleaning the jacks and it has seemed to work OK since. However, I've heard the circuit they used for this loop is very poorly designed and leads to common problems. Does anyone know what they are and if they might be responsible for my issues? I pretty much have to use it for my Eventide Space. One weird feature is that when using the loop your Master Volume control becomes much less effective but you can do crazy things with the volume using the pedal in the loop. It almost seems like the volume control on the last pedal becomes the master volume of the amp. What, if anything, should I do to make sure this amp is healthy and not about to make things worse?
Well bad jacks would explain your problem, there's nothing very complicated about the FX loop, as it's just tacked on the end of the reverb driver circuit. If you are using any kind of boost or buffered pedal in the effects loop, that's going to boost the signal going back into the amp and make your master volume seem less effiective.
Sounds like you cured your own problem, I wouldn't worry about it, unless you start having issues again. If you're looking for how to remove the effects loop, like I said, it's just the two jacks, you'd remove the jacks and bridge the connections between them permanently.
But surely not all FX loops are created equal? I've heard the first generation ones on the JCM 800s (which this is) are poorly thought out and were redesigned quite quickly. Is this hogwash? Thanks.
Well, I'm seeing two schematics for the 2205, one dated 1983 which includes a reverb, and one dated 1989, in both instances, the effects loop is the same, an interruption, post the reverb tank, and before the buffer tube stage. Same as it's done on the old Oranges, and so forth.
By the time you hit the JCM900's there's an op-amp buffering the send and return, but then the JCM900's are full of op-amps, and I suppose that's OK, if you like that kind of thing.
OK, I'm an arse, on the '83 schemo, the effects loops is drawn before the master volume which is post phase splitter, on the '89 it's drawn after. Yet that would mean they switched from a smart design to a stupid one. I suspect the '83 schemo is just drawn wrongly. Anyways, a bit of reading on the Marshall forum, and that's your problem area.
If you were brave, you could replace the master volume, with a 1M resistor, and move the Master Volume to the input of the tube stage after the effects loop, replacing that 1M resistor with it. That would probably help, if the thing is unlivable with. Or model it on the '83 schemo and use a dual 1M pot post phase splitter.
Depending on how much of the amp is on a PCB, this could be an easy mod, or a bitch. I never knew they made PCB'd jacks and pots on the JCM800 until Sunn showed me the innards of his. If you're lucky and the jacks are off the board, it should be a fairly easy mod.
IIRC there's some known problem with the switching jacks carrying too much current or voltage on the effects loop of some Marshalls, dunno if that's what's happening here though..
Quote from: moose23 on May 22, 2012, 04:19:59 PM
IIRC there's some known problem with the switching jacks carrying too much current or voltage on the effects loop of some Marshalls, dunno if that's what's happening here though..
That could be, maybe they used crappy jacks?
I did read this:
Quote
Nature of the beast due to the design. This is one of those that was placed AFTER the master volume, which is the absolute wrong place to install a loop within an amp circuit.
So the "proper" way to set it up would be to start with setting the input level on the FX unit to the 12:00 position, set the master on the amp to give you sufficient drive signal into the FX unit, then use the FX unit's output level knob as your "master volume". You may have to play with the amp's master setting and the FX unit's input level setting to get the right balance, but the end objective is to be able to use the FX unit's output level knob as a substitute for your amp's master volume.
Kind of a stupid way to do shit, but unfortunately due to Marshall's inferior design this would be about the only way to make this setup work without lots of noise/hiss.
hence my suggestion of just moving the position of the master volume in the circuit.
Hmm, interesting. Are there any "Do NOT do this..." that I need to know so that I don't damage anything?
That's hard to answer, what were you thinking of doing?
Who wants to help me fix an oscilloscope then?
What kind, what's it doing?
Unspecific dead power supply, according to the guy who gave it to me, he just bought another one as he had better shit to do than fix this:
(http://i17.photobucket.com/albums/b69/Incarante/stuff006.jpg)
Looks of an era, where it won't be a switch mode supply. I'd suspect it needs a cap job. They used the same style of multi-can caps in scopes as they did in tube amps. Go in, find the power supply, and fix ;)
Kinda what I was hoping.
I will say, multican caps are a bit of a bugger to remove from PCB's. Be extremely careful to get all traces of solder off the lugs or you'll end up tearing up the PCB. Solder sucker, followed by solder wick, if you have flux, use it. ;)
I found a neat trick of getting some silicon fuel hose for model cars and putting it over the end of the solder sucker, so you have a flexible tip that seals over a board well.
seriously..id never flex a board into a secondary circuit without amping up the voltage to at least match if not surpass the primary discharge level of negitive energy.
The amp rating for my Randall RG100SC
(http://i.imgur.com/mQKVx.jpg?1)
But the outlet cord I am using says
10A 250V
Am I damaging it?
Quote from: Instant Dan on May 29, 2012, 06:21:42 PM
The amp rating for my Randall RG100SC
(http://i.imgur.com/mQKVx.jpg?1)
But the outlet cord I am using says
10A 250V
Am I damaging it?
No, each is a maximum rating, the amp will draw the current it needs, the cord can handle the needs of the amp, and more, so you are fine.
I recently aquired a Laney Klipp that is in great shape. The previous owner had it serviced recently, with fresh tubes and caps. I played it for 5 mins, and it blew a fuse. I took it to a tech friend for a once over, and even retubed and biased it. He said everything looked great under the hood, and there were some nice upgrades, and jammed with it at full volume with no problems. I got it back to the space, played it for a few mins and again blew a fuse! What's up with this thing? I was running it at 16 ohms into a 16 ohm cab. I was plugged into the klipp channel with the vol at 4 boosted with a catalinbread boost pedal. Id be grateful for any advice.
So what is different between you playing it at your friends and at your space? Different cab?
Not knowing what else may be different I'd suspect either your cab is not what you think it is, maybe someone changed the drivers, or one of them is blown, or that the power in your practice space is suspect. Or it could be something mundane like a bad speaker cable.
So think, what changed between tech friend and practice space?
Yeah, I did check all of that.
After the klipp went out I played the rest of practice with my other amp. Both cabs are orange (16 ohms 4 V30 speakers) and I ran both of them no problem with a 120 watt Matamp at 8 ohms. My plan was to run both amps with a radial aby box. I had them both at 16 ohms with each amp running one cab with the split signal.
Well different amps react differently to different loads. Were you using a 16 ohm cab at your tech friends? Are you stacking it differently? Putting it on it's side? Which fuse is it?
I'll check it out tonight at practice. There are two fuses in the back. The one that blew is on the right when looking at the back of the amp.
It has top bollock Partridge trannies, so it should be pretty consistent with different impedance loads, but if one is wrong the high HT will make it a bit sensitive to stuff like brief open circuits and such. What valves are in there, don't get away with much on them. Good clean of the valve bases is sort of necessary also.
It is weird that it runs A-OK at your friends, and not in your practice space, that would imply the problem is outside the amp, not in it.
Unless, it's some weird transformer issue.
If he was willing I would ask your friend if you can take whatever setup he used, and run it at your practice space, just move it all, cables, cabs, etc. Or I suppose alternatively, take the exact setup of your practice space, round to your friend, and he can examine it all, I guess in retrospect that makes more sense. He can find any bad cables, bad drivers, etc.
Fixing things is so much easier when it's all on the bench in front of you ;)
Thanks for all of the suggestions. I will get to the bottom of this!
Let us know what it turns out to be ;)
I'm trying to think of a good way to hook up three taps from the OT for the different impedance options. Currently these Garnets that I have are hard wired to the output jack and in the event I want to hook up to a different impedance cab, I gotta open up the head and swap wires.
Any insight into a good triple throw switch to do this that can handle the current? I don't think a typical toggle is a good option here as it would likely be subject to inadvertant movement without me knowing it during transport.
The easiest way, I've seen done in high power amps, is separate jacks, one for each impedance tap.
(http://www.planetoftheamps.com/amp-compare-018.jpg)
You can buy impedance selector switches, Nick could get you one from cedist.com.
http://www.cedist.com/search/node/impedance%20select%20switch (http://www.cedist.com/search/node/impedance%20select%20switch)
Experiencing a mild burning smell today in the music room. Running a couple of new pedals but when I stick my nose near them they don't seem to be the source, nor is my amp or cabs ??? Nothing is burning in the kitchen or elsewhere in the house or outside. The air conditioner is off. I noticed a similar smell 6 or 7 years ago and couldn't locate the offending device then either. Weird.
Anything that hasn't been turned on in a while, could be burning off a layer of dust OR if you're overloading a particular circuit, you could be burning the wire in the walls. Lots of electricians use wire that's undersized for the breaker they put on a circuit. Ie putting a 20A breaker on a circuit with wire that should only carry 15A.
If the drywall catches fire, that'll be a clue ;)
I was boosting the signal and experimenting with stuff. I'll be more careful next time. I don't think I seriously melted anything though. That EH boost adds way too much gain by the way. Eventually I'll probably just break down and spend real money on a serious clean boost but we don't need to get into that topic again right now.
I offered to build you a passive volume ::)
Quote from: Hemisaurus on June 09, 2012, 03:37:09 PM
The easiest way, I've seen done in high power amps, is separate jacks, one for each impedance tap.
(http://www.planetoftheamps.com/amp-compare-018.jpg)
You can buy impedance selector switches, Nick could get you one from cedist.com.
http://www.cedist.com/search/node/impedance%20select%20switch (http://www.cedist.com/search/node/impedance%20select%20switch)
The Hammonds they refer to in the explanation of that rotary switch is what I have I believe. There is a feedback wire going back to the power section that makes that multi jack method difficult. The rotary switch was what I was after though. Thanks.
Why does the feedback wire make it difficult? They usually just come of the 16 ohm tap regardless, or is the Garnet different?
http://www.opentip.com/Musical-Instruments/Switch-Rotary-Impedance-Selector-p-1621668.html (http://www.opentip.com/Musical-Instruments/Switch-Rotary-Impedance-Selector-p-1621668.html)
I should add the Hammond is not for the feedback, but for the fact that rather than using simple taps and a common ground, the use separate coils, and link them in parallel or series depending on the impedance needed, is this how the Garnet works?
http://www.hammondmfg.com/1608.htm (http://www.hammondmfg.com/1608.htm) and scroll down.
It's on the last page of this PDF. The 10k reach around is what I'm talking about.
http://www.webphix.com/schematic%20heaven/www.schematicheaven.com/bargainbin/garnet_b260d_bto_bass.pdf
The way it's drawn, it looks like there are no taps, just two parallel jacks, with the feedback resistor. The one jack is shorted, so that if you don't connect a speaker you drive into a short rather than open circuit.
What I was attempting to say, badly, was if you have regular taps, you would take each tap out to a separate jack, and leave the feedback resistor connected to whichever tap it normally is connected to. Even if your speaker is not connected to that particular tap, it doesn't matter, it's still active for the feedback loop.
Whichever way you are most comfortable with, is the way to go though ;)
That makes perfect sense!!
I had attempted to do exactly what you're talking about (there are two parallel speaker jacks) then noticed that resistor going back there and figured that I needed to jump the new tap connection back to it effectively shorting the two taps together, which wouldn't work obviously.
But you're right, it's active anyway regardless of a load connection.
Thanks, for pulling me back from over thinking.
Incidentally, I'm not sure why the Garnet schematics never showed the different taps, but if you open one up, the other taps are tied off to a tab strip.
In the world of those Canadian amp heads, they say that for a stock Hammond 3 tap Xfmr, the yellow is 16, green w/Yellow is 8 and green is 4.
It's different for a two tap Xfmr.
Quote from: Hemisaurus on June 09, 2012, 04:08:55 PM
I offered to build you a passive volume ::)
How much? I want it. How many db?
Quote from: liquidsmoke on June 09, 2012, 09:10:33 PM
Quote from: Hemisaurus on June 09, 2012, 04:08:55 PM
I offered to build you a passive volume ::)
How much? I want it. How many db?
(http://images1.wikia.nocookie.net/__cb20100828054703/uncyclopedia/images/b/b5/Exploding-head.gif)
Quote from: Hemisaurus on June 09, 2012, 09:44:06 PM
(http://images1.wikia.nocookie.net/__cb20100828054703/uncyclopedia/images/b/b5/Exploding-head.gif)
I forgot, seriously. But the EH was only about $40 or so. I'm sending it back.
I want a true clean boost but don't want to spend big bucks.
If you boost the signal you will have more gain, it's fairly simple maths. Still it's probably worth trying the MXR Micro Amp for a flat clean boost even if it's just for comparison purposes.
Builder/Tech Q: I have an old Simms-Watts 200w tube PA head that's pretty shot, but the transformers are good. Can I clone a Hiwatt DR up to and including the PI and connect it to the 4 x KT88 output section of the PA amp? The power and bias supply will of course be completely rebuilt with new caps and diodes.
I've built tube gear before so I know about high voltages, but I haven't designed anything so far...
yes you could do the DR pre to pi but the DR201s have split rail power supply design which would be different here if the Simms Watt has a single rail supply. However, dont worry about this, should be fine.
(http://i1234.photobucket.com/albums/ff409/enslavedinrot/2012-06-19_21-24-15_757.jpg)
(http://i1234.photobucket.com/albums/ff409/enslavedinrot/2012-06-19_21-24-25_310.jpg)
http://www.ampix.org/albums/userpics/10075/Acoustic_140.pdf (http://www.ampix.org/albums/userpics/10075/Acoustic_140.pdf)
So, that blue cap is explodededed, and has no values. With my minimal schematic knowledge, it is... C106? .01?
Someone check my work? plz?
Unlikley, it looks like an electrolytic, and .1 is a pretty low value for that.
Seeing as it says 10-50 on it, I'm going to go with C111 the 10uf 50V cap.
We are talking about the metallic blue one at the bottom of the first pic?
Dah, the 'sploded one. Is there any method to reading these and tracing? Why cant all caps have ratings on them... :(
Would the shack have that?
Oh wow. Or I could have assumed it was the one in the logical place... right where it is on the board. Im dumb.
Yeah, back in the day, they didn't label caps consistently, some are default in uF some in nF, some maybe even in pF.
A fair guess for an electrolytic, which is one of those small 'can' type whether it has a lead at each end, or two leads at one end, is it's going to be > 1uF, so any number on it is going to probably be in uF so 10-50DC would be 10uF 50V DC.
Another clue is that electrolytics are polarised (they have a positive and negative), so as there are only a few caps on that schematic with a little + on them, that narrows your choices down more.
-taking notes-
Quote from: showdown on June 20, 2012, 09:27:06 AM
Builder/Tech Q: I have an old Simms-Watts 200w tube PA head that's pretty shot, but the transformers are good. Can I clone a Hiwatt DR up to and including the PI and connect it to the 4 x KT88 output section of the PA amp? The power and bias supply will of course be completely rebuilt with new caps and diodes.
I've built tube gear before so I know about high voltages, but I haven't designed anything so far...
Quote from: dunwichamps on June 20, 2012, 11:30:56 AM
yes you could do the DR pre to pi but the DR201s have split rail power supply design which would be different here if the Simms Watt has a single rail supply. However, dont worry about this, should be fine.
Simms Watts 200s ran in ultralinear, so the output section is pretty different, and according to Chambo, the output transformers weren't very good and barely made the 200w. Also some of the Simms 200 watters were 100v line out only, which makes them pretty fucking useless.
You can get 100V line to 4/8 ohm transformers, even up to and beyond 200W, they run about $60-80 here, you can just wire it on to the back of the O/P.
You don't need to run it in ultralinear mode, you can do it either way as well.
I was thinking of having switchable ultralinear, it should be a little tighter in UL if I want to play bass through it. Mine has the normal 8 & 16 ohm outputs (well, 7.5 and 15 ohms, but close enough).
I've read that the transformers are pretty good, but I can't tell who made them, there are no labels or stampings on them. And even if it can't fully make 200 watts, it should still be plenty loud :)
running it UL is fine, okay nice linear output with little thd as it was designed for. however, this is possibly not what you want if your going for a normal setup run in pentode/tetrode operation.
My favourite sounding amp is ultralinear, and I use it for guitar and bass.
It also has 60 year old tubes, not NOS, just the original tubes, which helps :)
I have UL/Pent switches on my amps using Kt88s with dynaco style iron. UL is a smidge less power but a different feel when you get it going. I like the option of switching, of course you gotta design it into the amp.
Quote from: dunwichamps on June 22, 2012, 12:31:24 PM
I have UL/Pent switches on my amps using Kt88s with dynaco style iron. UL is a smidge less power but a different feel when you get it going. I like the option of switching, of course you gotta design it into the amp.
A switch and a couple of resistors, not rocket-science. ;)
why does radioshack not carry the cap I need? Sigh.
Quote from: Hemisaurus on June 22, 2012, 03:30:37 PM
Quote from: dunwichamps on June 22, 2012, 12:31:24 PM
I have UL/Pent switches on my amps using Kt88s with dynaco style iron. UL is a smidge less power but a different feel when you get it going. I like the option of switching, of course you gotta design it into the amp.
A switch and a couple of resistors, not rocket-science. ;)
well physically just 1 switch, nothing else but the feedback changes a lot when you use it. Another thing to consider if your start with a UL amp it may not have separate screen supply caps ala a Model T so to make it operate in pentode you need to design the extra caps into the power supply or its not going to work.
Quote from: SunnO))) on June 22, 2012, 03:46:21 PM
why does radioshack not carry the cap I need? Sigh.
http://www.radioshack.com/product/index.jsp?productId=2103610&filterName=Brand&filterValue=RadioShack (http://www.radioshack.com/product/index.jsp?productId=2103610&filterName=Brand&filterValue=RadioShack)
W PALM BEACH CROSS CTY PL
01-8946 | 2.02 miles*
See a map
Store Hours:
Mon-Sat 9 am - 9 pm
Sunday 10 am - 7 pm
561-684-1131
CROSS COUNTY PLAZA
4348 OKEECHOBEE BVD H-100
W PALM BEACH, FL 33409
In stock In stock
Locally.
Oops your right, that's the other FL dudes zip.
Says it's in stock in all the Tallahassee Ratshacks though. At a pinch you can do two 4.7 uF's in parallel long as they are both 50V, do you need 50V, what's the supply voltage of that circuit? Maybe a 35V or even 16V might cover you. I was just going by the original part.
So, I cant access the sunn forum at all anymore... anyone got a silverface concert bass schematic and a proper transistor bias procedure?
The 140 is fixed, at least. Thanks, Herb.
i found an extension cab on craigslist and the guy wants to know asap if i'm gonna buy it
and i know this question was asked yesterday and i'm gonna be the big douche to ask it again
but is 2:47 am and i just got texted by the guy(crackhead?) and my search finger is tired
the speaker out on my head is 120w-4ohm
the peavey 2x12 in fantastic condition for cheap is 120w-4ohm
am i ok or should i wait for somethin with more watts or more ohms
thanks
The cab matches the head, so that's OK, assuming that the cab is rated 120W RMS, or continuous, and not Peak.
It does mean, you won't be able to use it with another cab though, without rewiring the cab or building a special box.
shit im sorry
its a combo 4x10
with speaker out 120w
so not just going through 2x12
i think its 200w altogether
thanks for quick answer
ima grab it
Quote from: Hemisaurus on June 09, 2012, 03:25:12 PM
Let us know what it turns out to be ;)
So, I have a thought on this Laney Klipp that's blowing fuses. With the voltage having been changed for use in the states, would the size of the fuse also have to change? I have the amp at a tech right now and he's running it through the paces, but the fuse thing seems logical since its the a/ c fuse that keeps going.
yes the fuse needs to change when from 220/240 to 120 VAC
and, to be all technical, generally times two, so 1.5A for 240V means 3A for 120V ;D
Yup. That was it. That, and just cleaning up some wiring that was really close together ( lots of electrical tape from previous "overhaul") and a rebias. Used it with another amp at a show this weekend with zero problems. Thanks ya'll!
SO, would I know if I lost a pair of tubes in my Model T? I was just playing it, and it dumped some volume on me and started getting a little dirtier (I wouldn't really know, I had a maxed out Caitlinbread SCOD in front of it.) It seems loud as fuck, still, but after the little ~tick~ it doesn't seem AS loud, maybe I'm having the placebo effect?
If something's a bit wrong, get it sorted before something becomes a lot wrong.
Like the man said, you lose a pair of tubes, your expected output impedance is now double, so you are melting your output xfmr the more you run it.
The obvious way to figure it would be to pull a pair of the output tubes, double the load, or flick the switch down one, try it out, then swap in the other pair. Or just put the tubes in an amp that runs only a pair.
Yep, dead tubes. The SCOD did it. So, I've got a quad of old, huge 6550s. If I drop them in, and flick the power, that's effectively a tube tester, right? If they all fire, I should be good for launch?
So, I finally got around to taking that Concert Bass to someone who is qualified. Got it back, filter caps were bad, but he said he didn't even suspect them due to what the scope read, then he just replaced them anyways, and it fixed the horrible noise issue. He said it was loud, but... it isn't. At all. Not as loud as it should be, at any rate. He said there's something wonky in the preamp, probably a bad cap. He pretty much told me to replace all of the electrolytics, but he didn't want to do it because I can do it myself.
What would the volume issue possibly be, if the poweramp runs perfectly flat on the scope? Preamp not sending enough signal?
If it's not the power, it's the pre.
So basically, just replace the caps and it should be loud as it should be?
What if i brute all of them and it STILL isnt loud? What's the next level?
I just hooked it up to the beta pre. Its loud.
Next level would be to trace it with a scope and see where you lose signal.
Proper. He said if it gets to that, he would scope instruct me.
One more, biasing the T, no different than doing the proper math for the proper mA? I hope?
biasing requires plate voltage, and cathode current. Your plate voltage * cathode current <= 70% * 42W for KT88s
Awesome.
So i have this amp:
(http://i140.photobucket.com/albums/r32/EXKid1975/a53e757b.jpg)
A Harmony H303a and I want to set it up so that I use it in front of a power amp. The amp is 8Watts RMS and sounds killer, but not very loud.
I've seen Garnet Herzogs that basically do this and put a resistive load on the output, then peel off the signal to go into the power amp. How big is the signal that I'm looking for here, so that I'm not trying to push a banana through a drinking straw? If I put an 8 ohm voltage divider (two 4 ohms in series) and tap it, think that'd get me in the ballpark?
Check the input sensitivity of your power amp. It will be somewhere between 0.75 and 1.5v, some valve slaves want a bit more. You can figure the voltage swing from 8w into whatever impedance you have, but the 8w might be at a low THD, so best of figuring the peak the amp can put out fully distorted and aiming for that, since you don't want to clip your power amp when you slap it with full voltage.
Thanks
You don't want a series voltage divider here, you want the 8 ohm load, or you can just leave the speaker in place, and the have a voltage divider across that load something big like a 1M resistor and a 1M pot, or a 500K if you have them handy. Bring it down to between 10K - 100K for a line level input.
The amount of current required by an input is negligible as is the effect of this large resistance across the speaker load.
Ok.
I just looked at the specs for the amp I'm after, (Stewart world 1.6) and it's Input sensitivity is 1V. I have a couple of 8 ohm heat sinkers in the garage, and I'll probably hook it up and get the scope out for the first time since I bought it.
Well think about it, 8W into 8ohm gives you 8V, but that's going to be RMS. Oddly Stewart don't mention the input impedance of the amp atall. Assuming a perfect input impedance a 1M pot in series with a 1M resistor, you'll get a 7.99997 ohm load for the amp. The pot will allow you to get a max of 4V out, with the pot fully cranked, and the amp seeing a 7.99994 ohm load.
Even at a line level 10K input using 10K pot and 10K resistor, your Harmony still sees 7.994 ohms of load, and you still get 4V max out.
In an idealised world a 10K resistor in series with a 68K resistor would get you to 1/8th of the max output, approx 1V, but I'd use the pot myself so you can play with the output level to get what you like, and adjust for the loading of the power amp input.
Wasn't in the manual, but was on the website
Input Impedance (Balanced/Unbalanced) 20k Ohms/10k Ohms
so 10K was a fair assumption.
Absolute minimal connection would be to hook a 68K to one terminal of the speaker in the Harmony, hook the other end of the 68K to the amp + (on barrier strip) and the ground to the other terminal of the speaker in the Harmony.
Got it, I had seen the input impedance as well.
I'd still probably go the pot in a voltage divider route, just for flexibility. If you have serious noise/hum issues, you could also get a little isolating xfmr, I know Weber and Jensen both make something that would do the job. This would also make the signal properly balanced, if you had a long cable run.
(https://taweber.powweb.com/store/balun.jpg)
I probably will. Here is how Garnet did it. This is two different schematics, the top one suggesting pretty much the same thing you are I think.
http://www.webphix.com/schematic%20heaven/www.schematicheaven.com/bargainbin/garnet_g12h_h-zog.pdf
Yeah pretty much.
Anyone have a basic 4-track usb mixer? In dire need.
Wrong Thread ::)
Yeah man, repost in the other stickied thread if you want, and I'll shitcan the post here (I tried to move it for ya, couldn't see how w/o dissecting the thread, maybe Jake0))) knows how?)
Just repost it, I'll clean up afterwards.
so my mod synth doesnt seem to work [ i just got this]..i have no idea how to get it to make sounds..all i can get it to do is make a hissing sound across 4 different modes..the volume affects that but nothing else is responsive..ive plugged the patch cords in so many different ways that i would have accidently made this thing make noise somehow..im thinking it doesnt work.??
Took me a while to get the ARP to make noise.
It's kind of an awkward question to answer without knowing the make and model, you should be able to make the oscillator (not the LFO) make some kind of sound, by patching it straight to the output, skipping the filters and waveshapers. There's probably primers out there, on how to make a Moogsynthitron Model #4 make noise.
Modes?
i say modes because i dont know the terminology..ill try and post a few pics..hang on
(http://sphotos-a.xx.fbcdn.net/hphotos-snc7/487166_442240089121894_822541675_n.jpg)
(http://sphotos-a.xx.fbcdn.net/hphotos-ash3/538690_442240929121810_1464735254_n.jpg)
(http://sphotos-a.xx.fbcdn.net/hphotos-ash3/582408_437987762880460_1739344003_n.jpg)
wn rn gn dn..they're the modes i was refering to.
Here's the harmony guts.
(http://i140.photobucket.com/albums/r32/EXKid1975/b970cd44.jpg)
But something has me scratching my head.
Here's the schematic:
(http://i140.photobucket.com/albums/r32/EXKid1975/2e14b3c7.jpg)
Here's the input jacks. J1 is on the right.
(http://i140.photobucket.com/albums/r32/EXKid1975/a342210d.jpg)
See how J3 connects to that resistor there, the schematic has it bypassed from J3. But the sound is quite noticeably higher gain in J3 as the schematic would suggest. Looking at this, J2 and j3 are in parallel.
I'm pretty giddy about this things simplicity.
Sorry morty, didn't mean to cockblock.
its cool..im thinking im fucked anyways..
Quote from: mortlock on July 16, 2012, 11:45:15 PM
its cool..im thinking im fucked anyways..
Can you get any sound from the saw out? That's the obvious oscillator to me.
mortlock, are you sure it's meant to make a noise without you applying a control voltage to one of the CV inputs? I'd either say read the manual carefully, post the schematic or prepare for a lot of twiddling.
Quote from: Pissy on July 16, 2012, 11:31:28 PM
Here's the schematic:
(http://i140.photobucket.com/albums/r32/EXKid1975/2e14b3c7.jpg)
Here's the input jacks. J1 is on the right.
(http://i140.photobucket.com/albums/r32/EXKid1975/a342210d.jpg)
See how J3 connects to that resistor there, the schematic has it bypassed from J3. But the sound is quite noticeably higher gain in J3 as the schematic would suggest. Looking at this, J2 and j3 are in parallel.
I'm pretty giddy about this things simplicity.
Sorry morty, didn't mean to cockblock.
Well either theres magic going on, the pictures don't tell the whole story, or you are imagining it.
It's a little hard to see, that 33K on the left, is it soldered through the J2 terminal to J3?
What do you read if you clip on end of your ohmmeter on where the two resistors join the cap, and then ohm out from the tip on each J? Maybe there is switching we don't see?
I read 34k from the J3 to the cap connection as well as continuity to that J2 terminal across the solid wire. J2 across the resistor is the same 34k.
I suppose I should measure to ground to see if there is a difference. There is noticeably more noise crackling from the J3 terminal. Also, my imagination wasn't influenced by knowing any of this. I played it then opened it up to see this. I had considered the same conclusion of influence.
I had only opened it up to install a 3 prong prep for that pre-amp mod I'm doing. Noticed the noise, then looked at this.
Have to look again when I get home tonight.
Yeah, it looks like it's only grounded via the chassis, but I'd expect a bad ground would give you less signal not more. Are you measuring from the tip of the socket, or the terminal? I'd try from the tip, or even plug a cable in, and measure from the tip of the cable on each socket, but it does seem kinda weird.
You could always modify J3 to resemble the schematic, for experimental purposes, or just short out that 33K resistor with a clip wire and see how it sounds.
Quote from: Hemisaurus on July 17, 2012, 08:09:20 AM
mortlock, are you sure it's meant to make a noise without you applying a control voltage to one of the CV inputs? I'd either say read the manual carefully, post the schematic or prepare for a lot of twiddling.
i dont have a manual..got it used and i dont know what you mean by control voltage to the cv input..dont forget you are talking to a complete novice when it comes to understanding electronics..
There's probably a manual online. What kind of synth is it? Is it the white noise generator that you hear? Also, the Cut-Off Freq (or other filter) may be clamping down on your signal, making it inaudible. It may take some serious tweaking, that's a lot of knobs to figure out with no manual. Has Larry tried it?
CV In can be used for an expression pedal, probably opens up a filter.
OK analog synths predate MIDI, a lot of the functions are controlled by voltage levels. So your controlling keyboard would output a different voltage for each key pressed.
http://www.analogue.org/network/cvolt.htm (http://www.analogue.org/network/cvolt.htm)
Do you have any info on the type of synth it is, based on a net schemo maybe? Also what type of patch cords is it using? Those look like they ground to the chassis, so I expect its using some kind of mini jack?
susanoo..or something like that..there was a youtube vid on the site when they were selling it..cant find it now..got it from noise fx..
Wow there is zero information on it.
http://www.noisefx.com/product_details/susanoosynth_analog_synth_2_fx1078 (http://www.noisefx.com/product_details/susanoosynth_analog_synth_2_fx1078)
What are you using for patch cables?
QuoteThe Susanoosynth Analog Synth 2 is an analog synth with a fat and strong sound. Controls for VCO1:FREQ. (Frequency of saw and pulse), VCO2:PULSE2 VOLUME, SAW VOLUME, PULSE VOLUME, P.ADJ(PULSE ADJUST), VCF:CUT OFF FREQUENCY, FREQUENCY OF THE PULSE2, LFO:LFO ADJ (LFO LEVEL), WAVEFORM, SPEED, and RESONANCE. Has jacks for 2 CV IN (-10V to +10V),PWM IN,SAW OUT and PULSE OUT, 2 CV IN,PULSE OUT, 2 LFO OUT, 2 CV IN(-10V to +10V) and 2 audio OUT (3.5mm and 1/4 inch). There are 4 noise generators including WN (WHITE NOISE), RN (ROAR NOISE), GN (GRAIN NOISE) and DN (DIGITAL NOISE). Each noise has one out and volume. It self-oscillates by tuning CUT OF FREQ. and RESONANCE like VCF of KORG MS-20. It runs on 12-volts. Made in
Japan!
Read that last line. I'd try hooking one of the noise generators to the output.
Make sure you're using a 12 volt adapter, too.
After looking at that vid. Try hooking one of the noise generators RN GN WN DN to one of the jacks marked INPUT play with the RESONANCE and FILTER knobs and go from there.
ha!! i hope you guys have cracked the code..
got it to work..i had to pause the vid and hook everything up the same way..i feel like im reverse engineering an alien piece of equipment..its cool. thanks for the help as usual.
Put the mod in.
My soldering skills are rusty, but they do shine.
(http://i140.photobucket.com/albums/r32/EXKid1975/6c81fdcc.jpg)
(http://i140.photobucket.com/albums/r32/EXKid1975/9f6fa145.jpg)
Added the pot (50k) and a 270 ohm straight to the Spkr jack. The 8 ohm brick is paralleled to gnd with the pot leg.
I still got some testing to do cuz, while it sounds good, I'm still not confident I'm bleeding enough off. It's pretty hot into an amp.
I plan on putting an ammeter on the signal to see, but how much is too much here?
I plugged it into a cabinet and can here it, which makes me think that's too much.
Just got the Stewart in today. $275 shipped.
(http://i140.photobucket.com/albums/r32/EXKid1975/9bc40969.jpg)
Edit: replaced that 270 with a 150k, but I'm thinking I need to make the brick a 6 ohm to really get the current going that way.
Yeah, I think you misread that schematic a little, the 270 ohm is meant to be between the pot wiper and the pseudo ground, the 150K resistor should be in series with the pot between the pot and the output jack, most of the voltage will be dropped across the 150K.
You worry about current don't, using a 270 ohm as the series resistor was your mistake, you had the speaker output across a 270 ohm resistor in series with your 10K amp input, which would mean that about 2.5% of the signal voltage was dropped across that resistor and the other 97.5% was at the amp input.
Compare that to a 150K, where 94% of the signal voltage is across the resistor.
The big power resistor of 8 ohms is just to sink the current to prevent the output transformer melting, it's not dropping the signal voltage for you, and changing it's value won't have any real effect on the output signal.
True about the schematic. I actually didn't look at it when I was installing. DOH!
So I should probably play with the varible resistance leg to get the signal where I want it, rather than messing with the static load leg?
I'm having a blast doing this btw. After I get this signal thing squared away, i'ma put a switch in it to bypass all this new stuff then put it back in the cabinet so I can still use it as an amp, be it through the stock 6" or otherwise.
Quote from: Pissy on July 20, 2012, 02:01:03 PM
So I should probably play with the varible resistance leg to get the signal where I want it, rather than messing with the static load leg?
If by variable resistance leg, you mean the one that connects to the output jack then yes. There should be a large resistance between the pot and the output jack. The schematic you pasted on the last page says 150K, with a .005 brite cap across it on a switch, you can leave off the brite cap, but you need a large resistor in there. Otherwise with the pot up full, the line output jack is effectively the same as the speaker out.
The big-ass power resistor is just a dummy for the speaker, it doesn't really affect the line output circuit.
sorry bout that
thanks for the info
Not a tech question, looks like a Peavey 212, ask in a buyer/seller thread?
Think I may have bought a broken Sound City L120 earlier. Will no doubt need help from you guys to get it sorted. Guess it's time I learnt how to fix amps as well as the pedals and guitars.
Guess I start with Oli's trick of stripping and cleaning everything and taking it from there.
Rebuild thread plz
i went overzealous in my strip down of the SC120R, im doing a full rebuild into a Hiwatt/Matamp GT120 mashup with El84 driven verb
I won't be overzealous I don't think. Looking forward to seeing what you do though Nick.
heres the stripped down chassis
(https://sphotos-a.xx.fbcdn.net/hphotos-ash3/s720x720/576039_10151281573414552_1198257701_n.jpg)
The preamp is a mix of the a GT120 but phase inverter and driver are right out of a DR103 with the exception that the PI is a cathodyne which is DC biased using the Hiwatt scheme. Then I will put in a parallel verb path, which is post EQ using an EL84 to drive it much like a 50s standalone fender reverb or the Or/Mat verbs. non master volume beast.
That isn't a SC anymore... :)
Quote from: SunnO))) on July 31, 2012, 04:28:54 PM
That isn't a SC anymore... :)
oh no but im kool with it. I have another 120 to refurb if I so wish.
Quote from: moose23 on July 31, 2012, 04:11:19 PM
Think I may have bought a broken Sound City L120 earlier. Will no doubt need help from you guys to get it sorted. Guess it's time I learnt how to fix amps as well as the pedals and guitars.
Guess I start with Oli's trick of stripping and cleaning everything and taking it from there.
Replace spewy electrolytic caps at very least, all of them ideally. After that is where I run out of ideas.
Yeah of course. Fairly sure it needs all new caps and a few tubes.
Quote from: dunwichamps on July 31, 2012, 04:21:28 PM
i went overzealous in my strip down of the SC120R, im doing a full rebuild into a Hiwatt/Matamp GT120 mashup with El84 driven verb
Yeah I missed the tech question here? >:(
'nother thread please.
Been sorting an amp I bought as 'serviced and working' on Ebay. Check what was in there:
(http://i17.photobucket.com/albums/b69/Incarante/ebay004-1.jpg)
Anyway, after recapping it, replacing all the dodge chained up resistors with the right ones and cleaning tons of exploded cap goo out of it, it gives me a fair squealing noise and bunches of distortion, any clues where to start poking at stuff? Valves are all new, since I have just had a delivery.
No comment ;)
Can any of you people apply your super powers knowledge toward my home theater surround sub woofer?
It sounds muddy, then kicks in like a ebow-moogerfooger combo.
If it sounds muddy, you may be feeding it too much high. Or your sub out is distorting. Or your driver is
busted. Or your amp is busted.
If it sounds like it's dragging, and sounds good at loud levels, most likely your driver.
I'm gonna try and F with it this weekend.
It easily pops its P's...and ultimately, belts oot solid, loud, tone that can only be stopped by yanking the power.
There are probably DVD's available with test-tones and useful setup stuff.
Has anyone ever seen a conversion of a "standard" sized 2x15 bass cab (vertical) into a 4x12 guitar cab (staggered speakers) before? I can't seem to find any online examples of someone doing this...? Just curious as to if there's any pitfalls to avoid or whether it's even a worthwhile undertaking. I'd like it to end up something like this Sceptre 4x12.
(http://lh3.ggpht.com/_eV5RciErQzw/S9ga7EwOWmI/AAAAAAAAA-4/AnPlwRhXvlo/s512/DSC00482.JPG)
Heavy Tim from Witches Tit took an old 2x15 and made a 4x12, I believe all he did was change the baffle ? (obviously the dimension was big enough to accomodate..)
/cloudy on more deets
I've wondered about cab philosophy when it comes to trying things like this. is the ideal enclosure volume listed for a specific speaker additive? As in if a speaker has 1.5cu ft listed as the ideal volume, would two of them with 3 cu ft work or would it be more ideal to separate them?
Quote from: Pissy on September 11, 2012, 07:48:32 AM
I've wondered about cab philosophy when it comes to trying things like this. is the ideal enclosure volume listed for a specific speaker additive? As in if a speaker has 1.5cu ft listed as the ideal volume, would two of them with 3 cu ft work or would it be more ideal to separate them?
Its per speaker, and dividing isn't really necessary unless its designed to blow some speakers and carry on like the SVT cab. You do get a bit more bass sensitivity from adding more speakers than higher though, so you can get away with a little less volume per speaker as you add more and have same low end, but the expectation is more bass from a bigger cab anyway. The separator would act as a brace to the newly bigger panel that might have some flex, so there is engineering considerations, best making it a brace though and not taking up as much air space.
Ampeg SS150 solid state head, volume dips way down after playing it for awhile. Works fine if the preamp is bypassed. My Laney "GH"(no idea why they called it that) solid state head does the same thing.
Cold solder joint issues probably?
Both of these amps are usable to me as power amps through the rear with pedals but since I'm now actually liking the sound of a pedal through the Ampeg's preamp(can dial in super heavy and bassy tones) and able to get quite a bit more volume that way I want to try to get this thing fixed.
It's unlikely you'd get a fault like that on both amps, what is different when you run with the preamp vs. on bypass, are you adding in a pedal, differentbcable, different pedal output? Does the volume go down and stay down, or become intermittent, how much of adrop are we talking?
The Laney will cut in and out after awhile, it happens through pedals and going from my guitar directly to it. It only happens on one of the channels and it's the "clean" one unfortunately. The distortion channel sounds pretty shitty so I don't use it.
I'll try Ampeg direct later today to make sure.
I feel like this is kind of what I get for buying older SS amps but I really like the Ampeg and want to keep using it through it's preamp.
SLM (Ampeg / Crate) does have some build quality issues, taking it apart, redoing the solder on all the pots, jacks and any large components, especially those mounted to the chassis or a heatsink is a good idea, as is cleaning the pots, and checking your cables.
Dunno about the quality of modern day Laney, but the same treatment won't hurt.
I think the Ampeg is from before they had anything to do with Crate but yeah after doing some Google searching it seems this problem isn't uncommon. The Laney is 20-25 years old I believe, very rare in the states. Got it on Craigslist with a 4x12 for pretty cheap.
Okay so I got things figured out with the Ampeg. Channel B is now a lot more quiet than it used to be. It's still loud but not loud enough for practice. Something must have went wrong inside. Used to be MEGA loud. Whatever happened happened at practice earlier in the week.
Well if you can solder the above is a good starting point for clearing up age related problems, after that you start looking for bad components.
If you can't solder, the tech you take it to will probably start by doing that.
SLM were responsible for the VH series Ampeg's, which had a lot in common with the Crate GX's.
Looks like I'll be working on it with a friend with help from someone who knows more or I'll be taking it in. Hopefully it's fixable. The B channel is great by itself for heavy rock sounds and I've realized that with pedals it's a monster for mondo gainy sounds.
Well, like I said, just look at the board, see where the stresses can be, which is where pots, jacks or switches are soldered to a PCB and also bolted to, or project through the chassis. Likewise, any large components, big capacitors, power resistors, anything with a bit of mass that can cause a solder joint to loosen overtime. Then look at things that are bolted to heatsinks, like power transistors, also any board to board connectors.
All these things undergo stresses over time, which can cause a solder joint to go bad.
Take your soldering iron, with a little bit of solder on the tip for heat conduction, and apply it to the joint, wait 'til the solder on the joint melts and flows making a good joint, wipe your iron tip, apply another little bit of solder, move on to the next joint.
Between doing this, and the fact you will be unplugging and replugging any connecting cables, you will cure a whole lot of problems. The strip it and rebuild it method is a great way to cure simple intermittent problems.
Cool, thanks for the guidelines. I hope to get started on it soon after I get back into town from a trip next week.
Does the type of solder I use matter? I only have what my dad had lying around for decades. It looks fine but I don't know what type it is.
Also wondering how much risk of getting shocked there might be.
As long as it's rosin-cored solder for electrical work, not stuff for plumbing, you should be OK. If you can find a little bottle of rosin flux as well, a drop of that on each joint as you heat it helps clean it up and let's the solder flow more easily. Don't worry if you can't find it, I haven't used it in about ten years, but if you see it, grab it.
(http://www.mgchemicals.com/images/product/835-100ML.png)
Not too big a shock hazard in solid state, the supply rails are usually 70V or less, but some caps can hold a charge still (only at tens of volts, not hundreds like in a tube amp), you can check them with a meter, or just short them out carefully. I did know a tech who used to search for low voltage live parts with his wet finger, but I'm not going to recommend that ;)
ive got electrical problems at my space
and amp seems to build up this static noise slowly
and then pops so loud the reverb springs shake
last night it sounded like thunder
so it may or may not be getting worse
any advice or quick fixes or do i need to time my riffs with it
A power conditioner maybe? If you are sure it's your power, I'm guessing the amp doesn't do this at home?
Are there any pedals involved?
yeah the peds got there own probs didnt want to bog you down with
im dealing with power supply soon
the amp does this even when everything else is unugged from it
even guitar
it doesnt come home from space since i got it
when i plugged it in when first got it, at my house,
it was quiet as a dead mouse
the power down there (at the space)is fucked, im sure grounds are big prob
is there something specific to use between amp and wall socket
you mentioned power conditioner but im clueless as far as electrical shit
brand and model number cause im big dummy
if the same thing would work for board thatd be awesome
thanks hemi
Well first off, I'd get an outlet tester.
(http://www.wiebetech.com/images/products//HotPlug_Accessories//Outlet_Polarity_Tester.jpg)
I'd also take the amp home again, and see if it does the same thing there.
If it only makes the noise at the practice space, and / or the outlet tester shows something wrong, I'd get the wiring repaired, call your landlord. The power conditioner would be a quick fix option, only after you are sure it's the power. I don't use 'em myself, couldn't give you a brand or model, lotsa people use Furman.
ill lug it home and give it a shot
looks like that power conditioner is exactly what im gonna need
landlords been wantin us out for a while,so hes not gonna be any help
thanks much hemi
you need a tip jar on here somehow(paypal button)
Are Epi pickups wax potted?
No clue. I do have an Epi bass, never looked at the pickup. Anyone ???
Quote from: CowboyJakeB on September 22, 2012, 11:07:09 PM
Are Epi pickups wax potted?
Yes.
At least the one I pulled out of my Explorer was but that's the only one I've ever had a look at.
One from my G400 were, ones in my plywood crappy epi weren't.
Here is why changing your power caps before they go short is important. I suspect tinfoiling a fuse might also be involved, but it hasn't arrived yet.
(http://i17.photobucket.com/albums/b69/Incarante/burnt2_zps465d07f0.jpg)
"Tinfoiling a fuse"?
(http://ampstack.files.wordpress.com/2012/04/foiled.jpg)
Prevents that pesky blowing they do and allows your amp to catch fire in a smooth analogue fashion.
Quote from: Mr. Foxen on September 25, 2012, 02:16:59 PM
Here is why changing your power caps before they go short is important. I suspect tinfoiling a fuse might also be involved, but it hasn't arrived yet.
(http://i17.photobucket.com/albums/b69/Incarante/burnt2_zps465d07f0.jpg)
fuck, someone burned a partridge.
Ha, I've been assuming those were Partridges since I got my first Burman, but it turns out they aren't. Spoke to a mate of Gregg Burmans, who checked with him, he had them custom made to a higher spec by two other companies, they are bigger than the Partridge trannies in equivalent amps, and the lacquer is much thicker.
Quote from: Mr. Foxen on September 25, 2012, 02:31:29 PM
Ha, I've been assuming those were Partridges since I got my first Burman, but it turns out they aren't. Spoke to a mate of Gregg Burmans, who checked with him, he had them custom made to a higher spec by two other companies, they are bigger than the Partridge trannies in equivalent amps, and the lacquer is much thicker.
they do have that look so I was tricked 2
We should put that at the beginnng of the thread with, a why you don't fuck with tube amps header :o
Quote from: Mr. Foxen on September 25, 2012, 02:24:20 PM
(http://ampstack.files.wordpress.com/2012/04/foiled.jpg)
Prevents that pesky blowing they do and allows your amp to catch fire in a smooth analogue fashion.
Sweet baby Jesus tap-dancing on the waters!
Whoever did that deserved what they got.
Added as General Knowledge ;)
The foiled fuse was in a not toasted amp, had some fucky caps that were probably blowing it, but it apparently worked, I never tried firing it up till I'd sorted shit I could see was wrong. I've actually seen more amps with a wire soldered across the fuse holder, so someone actually knew how to solder and did it, rather than a get me through the gig bodge.
Quote from: Mr. Foxen on September 25, 2012, 06:37:10 PM
The foiled fuse was in a not toasted amp, had some fucky caps that were probably blowing it, but it apparently worked, I never tried firing it up till I'd sorted shit I could see was wrong. I've actually seen more amps with a wire soldered across the fuse holder, so someone actually knew how to solder and did it, rather than a get me through the gig bodge.
When you used to be able to buy fuse wire in packets at the hardware store, we'd drill out the fuse and solder in a piece of fuse wire. That was before circuit breakers took over. Given the stupid fuse sizes and designs I've seen recently (board fuses, buss fuses, etc.) I miss being able to repair fuses.
(http://www.thelightworks.net/625-large/fuse-wire-card.jpg)
Possibly it's more a
not available in the US deal, perhaps they still have it at B&Q?
This isn't even the only one I've had like it, only one I photoed though. don't think fuse wire is ever copper, but not something I've paid much attention to.
(http://ampstack.files.wordpress.com/2011/10/laney-klipp-011.jpg)
Anybody have much experience tinkering with Boss pedals? I've got a Noise Suppressor that works fine in reduction mode, but in mute mode when engaged it seems to be stuck in mute. Adjusting the potentiometers for threshold and decay do nothing (though they work fine when in reduction mode)
Anybody have a quick idea on where the issue could be. I've opened it up twice and no wires appear to be damaged to broken loose, and no other obvious damage to the boards.
I realize that it may be more cost effective to just go buy another since its just a Boss...but it's the principle of the thing...
Quote from: morgantician on September 26, 2012, 01:46:48 AM
Anybody have much experience tinkering with Boss pedals? I've got a Noise Suppressor that works fine in reduction mode, but in mute mode when engaged it seems to be stuck in mute. Adjusting the potentiometers for threshold and decay do nothing (though they work fine when in reduction mode)
Anybody have a quick idea on where the issue could be. I've opened it up twice and no wires appear to be damaged to broken loose, and no other obvious damage to the boards.
I realize that it may be more cost effective to just go buy another since its just a Boss...but it's the principle of the thing...
In mute mode when the main / center LED is on you should hear nothing. When the main LED is off you should still see the gate LED go on and off as you play.
So in mute mode the pedal should be "off" when you are playing and "on" to mute your signal between songs or whatever.
In that case, my problem is then when not in mute, I'm getting no gate closing - the pedal lets all sound through as if it wasn't there at all (despite the knob settings).
Hmm, fault finding a pedal, sight unseen :)
My only question, if it sort of seems to be working, but isn't quite, is are you using battery or AC adpater. I'll relate the tale of my Boss pedal. It worked A-OK on battery, but did not work on DC adapter, until I used a 9.6V Boss adapter, in place of the 9V generic adapter I had been using, and then it worked fine.
So, sight unseen, try it on a battery, does it work differently?
It also seems like fallen may be best to explain how it works for you :)
Quote from: Hemisaurus on September 20, 2012, 04:35:22 AM
Well first off, I'd get an outlet tester.
(http://www.wiebetech.com/images/products//HotPlug_Accessories//Outlet_Polarity_Tester.jpg)
I'd also take the amp home again, and see if it does the same thing there.
If it only makes the noise at the practice space, and / or the outlet tester shows something wrong, I'd get the wiring repaired, call your landlord. The power conditioner would be a quick fix option, only after you are sure it's the power. I don't use 'em myself, couldn't give you a brand or model, lotsa people use Furman.
wanted to let you know i figured out my problem(amp popping)
it was the reverb tank
when i moved it the other night the springs made a thunderous roar and pop
its definately more of an issue than normal spring noise
so i turned the reverb completely off and it all went away
now im just chasin noise in my board
You need to listen to more dub, then you would know the sound of a reverb tank, King Tubby, Lee Perry et al. use it all the time ;D
Watch some of those Dub Trio videos, you'll see the guy shake his amp to get that Thunder sound.
the thunder is not what worries me
its the pop
its so loud,way louder than playing volume
and it does this when completely still,turned on,but no signal into it
even if my pedals arent plugged in, just sitting there idle ,it starts as static,then rumbles and BANG
always at the same volume,REAL FUCKING LOUD,every 2 minutes or so
lee scratch perry would not like this at all,i think he would call it "your mothers cunt" or "modascunt"
I think bumbahclat would be more likely, and that refers to an item a women needs to wear every mooncycle if memory serves.
So it's a pop, in the reverb circuit, but it's not the tank itself, as it happens when the amp is absolutely still, no vibrations, no nearby feet/drums/guitar noise, and it happens everywhere, not just at your practice space?
Randall Commander IV? Time to look for a schematic.
good luck finding anything about it
but yeah no vibes, we just stood there starin at it
and like i said when i dialed the reverb to zero it went away
but it has to be zero not even a smidge
i figured since it went away i didnt have to bring it home,but if you still think the power might be an issue
no other gear down there does this, but there is alot of noise with pedals
and hum from certain circuits
ill bring it back this weekend
Well if you email amp.support@usmusiccorp.com with your model and serial number, and ask, they will send you a manual and schematic, which you can then let me look at ;)
Sounds like something arcing, I'd get in there with alcohol and cotton buds and clean everything, especially shit that looks a bit sooty, then run it open and jab loads of stuff with a chopstick and see if it makes anything bang. Had a similar issue with an SC120 someone else recapped, and it turne dout one of the joints had a load of burned shit melted into it so it was being intermittent.
Solid state, less likely to be arcing, more likely to be a leaky cap ;)
Hence the schematic.
thought i replied,shit
ill get the schematic
i was resigned to fact that the reverb wasnt gonna work no more
but if you can walk me through gettin it up and running,that'd rule
cause it sounds pretty good
Cab question: I picked up a Peavey TVX 810 off of Craigslist for a song last weekend. The owner said the tweeter wasn't acting right.
These have that active tweeter, with a potentiometer right below the input jack on the back. Here's my question: since I could give a shit about an active tweeter, in theory could I just disconnect the leads on the tweeter and take it out of the circuit and the rest of the cab still be functional? I'm hoping its overall impedance (4 ohms) isn't calculated including any resistance the tweeter has, and this is just an extra bell/whistle to the cab.
Can't you just turn the tweeter off with the pad (pot)?
Not knowing what the crossover circuit is in that cab, I'd recommend just turn the tweeter off with the pad or take the input jack plate off, and figure a way to connect the input jack direct to the woofers.
If when you open it up, the tweeter is just a piezo with a pad on it, and there is no actual crossover circuit, then yeah, go ahead and cut it out.
So I think I just blew a power transformer. I was replacing the bias range resistor (470 ohm between diode and B+ winding of the transformer) with a 680 ohm resistor to lower the bias range, and there was a pop and a great deal of smoke. The pop was of the first filter cap in the bias supply exploding, and the smoke came from around the power tranny (laydown mount). I'm thinking the bias supply wasn't grounded. Moral of the story: CHECK ALL GROUNDS BEFORE YOU POWER UP! I know, stupid amateur hack mistake, but it's going to cost me $80 to replace the power transformer. >:(>:(>:(
Well if you're savvy enough to be doing all that. I'd suggest before you remove the tranny, try disconnecting all the windings from the rest of the circuitry, and see if it runs no-load, or if it still burns. It's very hard to get smoke out of a tranny, especially without evidence like scorch marks, or melted wax running out of it. The most likely source of smoke is gonna be a carbon resistor, maybe something silicon if you have it, like a diode, voltage regulator or transistor.
So disconnect that tranny, run it up, see if the windings are all intact, if your running it no load expect the voltages to be a little high.
Hopefully you maybe just burned a voltage dropping resistor in your bias supply or something else easily replaced. Have a look and a sniff. ;)
Fingers crossed.
Thanks, Hemi. I hope I smoked the rectifier diodes. It's a Marshall clone, and it has a 25A bridge diode mounted right above the transformer on the side of the chassis. I'm hoping it blew that.
Well silicon blows pretty quickly, so here's hoping :)
Quote from: Hemisaurus on October 01, 2012, 08:17:10 AM
Can't you just turn the tweeter off with the pad (pot)?
Not knowing what the crossover circuit is in that cab, I'd recommend just turn the tweeter off with the pad or take the input jack plate off, and figure a way to connect the input jack direct to the woofers.
If when you open it up, the tweeter is just a piezo with a pad on it, and there is no actual crossover circuit, then yeah, go ahead and cut it out.
There was an issue with the tweeter somewhere on its little board, so hence me wanting to take it out rather than just turn it down. I ended up just removing its electronics all together and wired the speakers to a fresh 1/4" jack. Worked perfect after that (and I won't have to worry about other things on the tweeter board going awry and having to fix something else).
Yep, best way ;)
Thinking about buying a micrometer to measure patch cord plugs. I'm pretty sure that fatter plugs connect way better. Not sure if getting a cheap one ($10 or so) would be wise though.
It's a vicious cycle, fatter plugs will make a better connection, until your jack socket stretches, and now your back where you started, except your sockets are even more stretched. You can retension them, but one they're worn out, it's only going to help so long.
$10 may get you a half dozen or so nice quality jack sockets, replace your stretched sockets instead. The bad news is a lot of modern amps use PCB mounted jacks, which need to be replaced with something with an identical pinout to fit.
I should also add that PCB mounted jack sockets are far more prone to bad solder joints, quite often the jack doesn't need replaced, just resoldered to the board.
Maybe I'll just stick a patch cord jack in my eyeball.
The problems never fucking end. >:(
It's a wonder that touring bands can get any sort of sound out of their rigs at all.
Some pedals get played for decades being plugged in and unplugged hundreds or thousands of times and still connect to non-fat patch cords. That is another wonder.
It sucks I know, but fixing the jack sockets is a better solution. Using bigger jack plugs is kinda like using a bigger value fuse in an amp that keeps blowing, it works, but it's not the right way to do it (though there are cases where mfgs mis-spec fuses).
It'll feel worth it when you can plug your cable in, it goes in firmly, and theres no scratches and crackles if you accidentally move the cable. I'm guilty of it myself, having jack sockets where you have to loop the cable to get the right angle for the socket to work, it's crappy and gets annoying.
Quote from: Hemisaurus on October 05, 2012, 03:44:08 PM
It sucks I know, but fixing the jack sockets is a better solution. Using bigger jack plugs is kinda like using a bigger value fuse in an amp that keeps blowing, it works, but it's not the right way to do it (though there are cases where mfgs mis-spec fuses).
It'll feel worth it when you can plug your cable in, it goes in firmly, and theres no scratches and crackles if you accidentally move the cable. I'm guilty of it myself, having jack sockets where you have to loop the cable to get the right angle for the socket to work, it's crappy and gets annoying.
This is why I'm selling my motorcycle that needs work in the spring, too much other shit to do.
Any websites that detail how to fix or replace jack sockets?
Use the google if you have to, seems to be some videos and guides out there. I'd just open it up and take a look, observing the usual safety precautions, outlined elsewhere in this threaf. Your gear is SS so a bit less deadly for the most part.
Can one get a shock from pedals? If so that's news to me.
One thing I've noticed is that if the pedals are moving around at all on the floor or board when you are kicking them on and off they are more likely to squawk. I have a few that have not been given the velcro treatment yet, I'll get on that ASAP.
Yep, if they plug into the wall like my DOD690, or if they have a tube and use one of those 9V AC to 260V AC transformers. If they run of a battery you're pretty safe.
I didn't have any problems at practice yesterday and then last night I velcroed the last 3 down so I'm hoping things will stay quiet.
I have a toob question. On my Egnater Tweaker 15wt I swapped out all the tubes experimenting. I put a matched set of Tung Sol 6v6gt's in and the tone improvement was very noticeable. But after about 15/20 minutes of lower volume playing the volume dropped almost all the way off. And I notice one of the tubes is glowing hot. I turn it off for a few seconds and it comes back on normal, then craps out again later. It didnt do it before the tube swap, could it be the new tube? Or fucked up amp? Ill swap tubes back later.
Quote from: bass sic on October 10, 2012, 02:13:34 PM
I have a toob question. On my Egnater Tweaker 15wt I swapped out all the tubes experimenting. I put a matched set of Tung Sol 6v6gt's in and the tone improvement was very noticeable. But after about 15/20 minutes of lower volume playing the volume dropped almost all the way off. And I notice one of the tubes is glowing hot. I turn it off for a few seconds and it comes back on normal, then craps out again later. It didnt do it before the tube swap, could it be the new tube? Or fucked up amp? Ill swap tubes back later.
No refunds! ;)
Bias issue?
Redplating, where the plates in the tube glow red, is usually caused by some kind of bias problem, where the tube gets turned full on. Kinda like if your throttle jams open.
It's more likely to be the amps than the tubes I'm afraid, but if a tube has been allowed to redplate for a while it usually warps the plates, and so should be replaced as well. Is the tweaker one of those self bias jobs, if so tech time :-\
I don't remember if the Tweaker's instructions mentioned biasing when changing tubes.
Just read them, it says if amp needs servicing or biasing, could be bad biasing causing tube failure. New tubes and a bias job might be the fix.
could be a poor tube, bad bias supply or improper grid leaks.
I'm told you can't bias this amp.
I'm gonna go with bad tube, since it started right after the swap. I hope.
Bassic, you should have left those tubes alone. ;)
Actually, that's why I'm scared to tube swap if things are running fine.
Yea, it was fine. But could always be better. Sounds fucking incredible until meltdown.
QuoteAre the Egnater amps cathode or fix biased?
All of the models, with the exception of the Tweaker, are fixed/adjustable bias with easy to use test points. Consult the owner's manuals or contact support@egnateramps.com for information on how to properly adjust the bias. The Tweaker is cathode biased so there is no adjustment required when replacing tubes.
So stick back in the old tubes, in the same place you took them out if poss. and see if it works.
I put the stock ruby's back in and so far after an hour no issues. We will see how thetubestore.com deals with refunds. It did sound really good.
Quote from: bass sic on October 10, 2012, 02:48:08 PM
I'm told you can't bias this amp.
Everything ever can be biased.
Maybe he should have been more precise, it can't be biased by default.
Actually, it is biased, it's just a non-adjustable bias, if it wasn't biased it wouldn't work.
This unit, in it's default state, has a non-adjustable bias voltage.
like every mesa I have seen. Non adjustable fixed bias, i know a fuckin weird name for it.
I agree with Randall whassisname about PCB's, but not giving users a chance to bias their unit is just lazy.
Randall Smith is the name. His Kool-Aid belongs with his products and nowhere else. I'll keep my bias controls thank you.
Quote from: Hemisaurus on October 24, 2012, 11:58:48 AM
I agree with Randall whassisname about PCB's, but not giving users a chance to bias their unit is just lazy.
I think amp companies are worrying about liability in the form of you screwing you amp up with improper bias and or having to open the amp up to bias it causing potential death. however its all dumb IMO but I do wish modern manufacturers would actually make it easier to bias shit with B+ and cathode current taps to measure bias instead of having to open up the amps to get that stuff
When I bias a Mesa I bring out two or three sets of tubes and swap them until I get the bias I want.
Quote from: FullCustom on October 24, 2012, 12:14:28 PM
When I bias a Mesa I bring out two or three sets of tubes and swap them until I get the bias I want.
sounds like a pain in the ass but not much better than an amp with just 1 bias adjust for 4 output tubes.
Quote from: dunwichamps on October 24, 2012, 12:21:44 PM
Quote from: FullCustom on October 24, 2012, 12:14:28 PM
When I bias a Mesa I bring out two or three sets of tubes and swap them until I get the bias I want.
sounds like a pain in the ass but not much better than an amp with just 1 bias adjust for 4 output tubes.
Factory matched tude set are fine with a single bias control. Groove Tubes never setup how I want them to, sometimes they're as much as 10mA apart. I can dig around in my boxes of used junk and fine tubes matched better than that.
i guess it will depend how well the tubes are matched, how burned in they are as well so they dont drift all over the place during initial play. Its another thing where at minimum dual bias pots should be used 1 for each half of the push pull.
I'm sitting here biasing a DSL100 and eating my lunch. The dual bias pots aren't help it. It is however doing a great job of making a set of JJ EL34 tubes unbalanced. If this was a JCM800 I would have been done with the amp before I finished my applesauce.
Quote from: FullCustom on October 24, 2012, 01:06:11 PM
I'm sitting here biasing a DSL100 and eating my lunch. The dual bias pots aren't help it. It is however doing a great job of making a set of JJ EL34 tubes unbalanced. If this was a JCM800 I would have been done with the amp before I finished my applesauce.
no experience but probs a crap amp then
Quote from: dunwichamps on October 24, 2012, 02:09:43 PM
Quote from: FullCustom on October 24, 2012, 01:06:11 PM
I'm sitting here biasing a DSL100 and eating my lunch. The dual bias pots aren't help it. It is however doing a great job of making a set of JJ EL34 tubes unbalanced. If this was a JCM800 I would have been done with the amp before I finished my applesauce.
no experience but probs a crap amp then
Don't fear what you don't understand
i dont fear it, but if you cant bias it with dual pots to within a mA or so then something else is problematic. either the tubes are bad or the bias pots dont have enough negative swing ect ect.
how are u measuring cathode current?
I can't tell the back line company that owns this amp that it's a crap amp. I have to fix it and it has to be stock when it's done. So far it is looking like the output transformer lead dress was the problem.
Quote from: FullCustom on October 24, 2012, 02:57:19 PM
I can't tell the back line company that owns this amp that it's a crap amp. I have to fix it and it has to be stock when it's done. So far it is looking like the output transformer lead dress was the problem.
was the OT taps shorting? Or are the leads too close to sensitive circuitry causing PO?
Marshall does this thing where they tie wrap all the OT leads to the back panel. It's neat and tidy but it's wrong.
Quote from: FullCustom on October 24, 2012, 03:15:05 PM
Marshall does this thing where they tie wrap all the OT leads to the back panel. It's neat and tidy but it's wrong.
ahh yes they dont do the split transformer setup (ala Hiwatt and others) which I think is a far superior way of doing the OT/PT positioning. Is there enough lead slack to rerun the wires are will you have to extend them to reposition?
Um, go look at some JCM2000 pic. The OT positioning is fine, it was just the lead dress.
Quote from: FullCustom on October 24, 2012, 03:37:39 PM
Um, go look at some JCM2000 pic. The OT positioning is fine, it was just the lead dress.
my bad. So they run the primary with the secondary along the back panel?
Quote from: dunwichamps on October 24, 2012, 04:13:22 PM
Quote from: FullCustom on October 24, 2012, 03:37:39 PM
Um, go look at some JCM2000 pic. The OT positioning is fine, it was just the lead dress.
my bad. So they run the primary with the secondary along the back panel?
Yup, tie-wrapped together nice and neat like. The RF bleed was making one side run hot.
Quote from: FullCustom on October 24, 2012, 04:29:11 PM
Quote from: dunwichamps on October 24, 2012, 04:13:22 PM
Quote from: FullCustom on October 24, 2012, 03:37:39 PM
Um, go look at some JCM2000 pic. The OT positioning is fine, it was just the lead dress.
my bad. So they run the primary with the secondary along the back panel?
Yup, tie-wrapped together nice and neat like. The RF bleed was making one side run hot.
ahh so their was coupling between the primary and secondary causing PO and excessive current. That sucks.
Happens on a lot of amps, Blue Jr's are famous for it. People blame it on the PCBs but it's just OT lead dress.
yea i thought rule of thumb was keep your OT primary and secondary leads far away from each other, and the secondary far from the output tube sockets.
Yes, sir, correct.
Man wouldn't that be amp building basics??. Fender and Marshall have been making amps now for how long? shit
Have I mentioned Marshall are shit and gay?
Quote from: Mr. Foxen on October 24, 2012, 05:27:03 PM
Have I mentioned Marshall are shit and gay?
If my Marshall is gay then it is one mean ass bull queer
amp makers have long been cutting corners from underspecced PTs, improper heater wiring, lack of shielded cabling on sensitive grid wires, bare minimum spec resistors, underspecced caps.....
And the PV VK100 is the biggest turd of them all. You have to RF Snub the hell out of the OT to make it work.The only amp that I have ever see that is less stable with NFB.
I see shielded cable as more of a band-aid. I've seen shielded cable work more as an antenna than a ground plane in some amps(Dr Z/later Fender).
you dont wanna overdue the shielded cable since often it has no benefit but the first grid wire from the input, and usually the NFB run from the Tap Selector back to the NFB resistor are the 2 most important shielded runs I do in my amps. The result of the grid wires are so short that I wouldnt see much benefit from shielding them and its more of a pain to run a coax cable there.
Real quick guys, and then back to the discussion. I have two 50wt speakers that ohm out at 12 ohms. That would make them 16 right? And if I wire them series they come in at 22 ohm which is too high. Wired parellel they read 6 which would make it a 8 ohm cab. Am I right here?
Quote from: bass sic on October 25, 2012, 02:14:54 PM
Real quick guys, and then back to the discussion. I have two 50wt speakers that ohm out at 12 ohms. That would make them 16 right? And if I wire them series they come in at 22 ohm which is too high. Wired parellel they read 6 which would make it a 8 ohm cab. Am I right here?
yea generally the DC resistance is usually a bit smaller than the impedance so thats a solid bet
Sweet thanks. I'm putting the final touches on this cab build and hope to be test driving it tonight.
(Ampeg SS150 head, B(clean) channel volume is a lot more quiet than it used to be, the destructive event happened at practice weeks back) update:
Second shop said they can't find anything wrong with it. Fortunately I'm only out $36 so far. Decided not to try to work on it myself although I did look at the innards with a friend who knows more than I do(which is nothing) about electronics.
This amp used to be insanely loud, now it's only fairly loud. It's still usable but it sounded better before. First shop said it tested at 150 watts which is what the back of the amp listed. I'm confused. Having thoughts about trying to ship it to one of you amp builder types to do what is needed to get it working like it should. Or I'll just buy a solid state rack power amp and a ss rack pre amp that can do super clean tones. Or try to have one of you amp builder types rip the pre amp out of the Ampeg and put it into a stand alone box to be used with a power amp because I like how I can crank the bass knob and make my speakers fart even if I don't do that normally. It can do a Laney AOR like bass boost times 2. From what I've read some bass players actually use this head although I would think the power might be a bit on the low side for loud rock and metal.
what would it take to replace rca jacks on an old synth..is it hard to do??
Could one of you guys recommend a transformer for matching mic level to line level like this:
(http://www.colomar.com/Shavano/matchtrn.gif)
http://www.colomar.com/Shavano/cable_xlr_to_phone.html
Mort, Depends on your competence. It could be simple, it could be a labyrinth of fuckfuckfuck.
New old amp day.
Montgomery Ward GIM-9011A
(http://img.tapatalk.com/d/12/11/10/na6ugu8a.jpg)
(http://img.tapatalk.com/d/12/11/10/vy6a7ava.jpg)
(http://img.tapatalk.com/d/12/11/10/ja2y3aje.jpg)
(http://img.tapatalk.com/d/12/11/10/ybebejup.jpg)
(http://img.tapatalk.com/d/12/11/10/4uda2ype.jpg)
(http://img.tapatalk.com/d/12/11/10/beduby3u.jpg)(http://img.tapatalk.com/d/12/11/10/neveduzy.jpg)
(http://img.tapatalk.com/d/12/11/10/3emanaqe.jpg)
Came with about 10 of these:
(http://img.tapatalk.com/d/12/11/10/qysu8a8e.jpg)
And the reason I posted here as opposed to new acquisitions:
(http://img.tapatalk.com/d/12/11/10/atabuqyq.jpg)
Any idea where it goes?
Gonna be a hunt the legs mission.
Been looking. Going to send it to a buddy that doesn't need bi-focals.
Quote from: bass sic on October 10, 2012, 02:13:34 PM
I have a toob question. On my Egnater Tweaker 15wt I swapped out all the tubes experimenting. I put a matched set of Tung Sol 6v6gt's in and the tone improvement was very noticeable. But after about 15/20 minutes of lower volume playing the volume dropped almost all the way off. And I notice one of the tubes is glowing hot. I turn it off for a few seconds and it comes back on normal, then craps out again later. It didnt do it before the tube swap, could it be the new tube? Or fucked up amp? Ill swap tubes back later.
So here's a little update, I put the stock tunes back in and had no problems since. Then last week they sent me the replacement Tung Sol tunes and they've been working fine for a week now. It had to be bad tubes from stock.
When a solid state amp is cranked way up and clips somewhat is it hard/damaging on certain components of the amp? You'd think 380 watts would be enough for all the volume one would ever need for guitar with 2 cabs but it clips pretty easily. I don't have 2 grand for EVM12L's and a 1,000 watt amp so this will have to do.
edit: Mosvalve 500. I think it's loud enough without clipping, just barely. Better than the SS150 by itself which gets nasty and too sludgy too quick.
Generally they aren't designed to be run in clipping for long, but doesn't necessarily mean it will break. Rigging a high pass filter is your best bet for making it run cleaner much louder
Quote from: Mr. Foxen on November 16, 2012, 07:33:36 PM
Generally they aren't designed to be run in clipping for long, but doesn't necessarily mean it will break.
Ah. I was running the SS clipping for 90+ minutes at practice.
Quote from: Mr. Foxen on November 16, 2012, 07:33:36 PM
Rigging a high pass filter is your best bet for making it run cleaner much louder
Doesn't this effect tone? I do use an eq pedal to take out some of the lows.
380 watts and the thing is clipping and smelling weird. It's older but still.. WTF? Guess I need 600 watts? My cabs can each handle 300.
I have no idea how people manage with those 120/150 watt SS heads.
Looking like it's either upgrade my cabs/speakers for higher wattage handling(which will cost a shit ton) so I can maybe go up to a 600-800 watt SS power amp or look into a '70s SVT head(also pricey I bet) assuming it wouldn't blow two 300 watt cabs which would also be expensive. This shit never ends with this band. Cabs are either shutting down, clipping, or melting. Perhaps we should do acoustic. I have no idea how much vintage SVTs go for but I understand that they sound pretty good for guitar unlike the newer ones with preamps designed specifically for bass.
Quote from: liquidsmoke on November 16, 2012, 10:37:44 PM
Quote from: Mr. Foxen on November 16, 2012, 07:33:36 PM
Rigging a high pass filter is your best bet for making it run cleaner much louder
Doesn't this effect tone? I do use an eq pedal to take out some of the lows.
It will take out clipping and speaker fart, depends if those are part of your tone. You pretty much set the filter to below what your cab is capable of outputting, with a sealed SVT type probably 50-60hz, 40hz for a reasonable ported cab, awesome ported cab 30hz. If its guitar and you have a bassist, can set it higher still, give bassist some room. Wattage handling in cabs is pretty much irrelevant to clipping, you want more sensitivity if you want to be louder without clipping, since you need less power to get there, plus if its the speakers farting, the watt rating is irrelevant to that, since its excursion limit that determines when they fart.
Quote from: Mr. Foxen on November 21, 2012, 10:06:14 AM
Quote from: liquidsmoke on November 16, 2012, 10:37:44 PM
Quote from: Mr. Foxen on November 16, 2012, 07:33:36 PM
Rigging a high pass filter is your best bet for making it run cleaner much louder
Doesn't this effect tone? I do use an eq pedal to take out some of the lows.
It will take out clipping and speaker fart, depends if those are part of your tone. You pretty much set the filter to below what your cab is capable of outputting, with a sealed SVT type probably 50-60hz, 40hz for a reasonable ported cab, awesome ported cab 30hz. If its guitar and you have a bassist, can set it higher still, give bassist some room. Wattage handling in cabs is pretty much irrelevant to clipping, you want more sensitivity if you want to be louder without clipping, since you need less power to get there, plus if its the speakers farting, the watt rating is irrelevant to that, since its excursion limit that determines when they fart.
Interesting.
"Wattage handling in cabs is pretty much irrelevant to clipping"
Now I'm really confused. I would expect clipping at even moderate volume levels if I ran a 400 watt amp into a 100 watt cab. No?
I have a sound city that suddenly started a loud buzzing and popping while it is being played. If I just plug the guitar in there is no noise, the moment I hit the strings the noise starts--loud enough to be heard over anything being played. At the same time the noise problem started the amp experienced a severe volume drop. Before it would peel the paint off the walls on 7, now the drums drown it out fully cranked. I've tried different guitars, cabinets and cables all with the same results.
I realize I'll need to take it in to a tech but they're closed for the week for the holiday and I'm trying to get a general idea of what I'm looking at.
Any thoughts?
Quote from: liquidsmoke on November 21, 2012, 12:29:20 PM
Interesting.
"Wattage handling in cabs is pretty much irrelevant to clipping"
Now I'm really confused. I would expect clipping at even moderate volume levels if I ran a 400 watt amp into a 100 watt cab. No?
Factors other than watts determine how loud and when it clips. If the cab is 125db when fed 10w, its going to be loud without clipping, and you just don't need to push the amp so hard. Also, you could clip a 500w rated cab with a 400w amp if the cabs excursion limit is 100w (which is often the case with 4x10s). It is the xmax of a speaker that determines when it will clip, which is unrelated to the thermal power handling. Thermal handling ratings on speaker are almost totally irrelevant but its the biggest number so it gets shouted about most.
Quote from: beerrhino on November 24, 2012, 11:42:10 AM
I have a sound city that suddenly started a loud buzzing and popping while it is being played. If I just plug the guitar in there is no noise, the moment I hit the strings the noise starts--loud enough to be heard over anything being played. At the same time the noise problem started the amp experienced a severe volume drop. Before it would peel the paint off the walls on 7, now the drums drown it out fully cranked. I've tried different guitars, cabinets and cables all with the same results.
I realize I'll need to take it in to a tech but they're closed for the week for the holiday and I'm trying to get a general idea of what I'm looking at.
Any thoughts?
I've had some do this, turned out to be bad solder joint/resistor, I just brute force replaced resistors in the pre until it worked right, the carbon comp resistors in there are a bit shit anyway, so better with new ones.
I have an old Marshall cab that I run a Sovtek Mig-100 head into. Lately, certain notes will cause the entire cabinet to emit this overwhelming buzz. It's not feedback, more like a massive vibration. Thinking a speaker was loose, I tightened all of them. But, it didn't help. Any ideas? I'm hoping it's not some kind of a crack in the frame itself.
Anything else being loose. Wood inside, a wire touching a cone sometimes, a crack in the case, dust cap on a speaker separating.
Okay, I'll investigate all of those possibilities. Thanks!
Fender Bandmaster, Vibrato knob turns volume down, what the hot fuck?
Quote from: SunnO))) on November 28, 2012, 05:12:53 PM
Fender Bandmaster, Vibrato knob turns volume down, what the hot fuck?
hmm. something in the vibrato circuit is allowing the uneffected signal to pass through . . . what kind of circuit is it? tube? photo cell?
Quote from: justinhedrick on November 29, 2012, 10:47:27 AM
Quote from: SunnO))) on November 28, 2012, 05:12:53 PM
Fender Bandmaster, Vibrato knob turns volume down, what the hot fuck?
hmm. something in the vibrato circuit is allowing the uneffected signal to pass through . . . what kind of circuit is it? tube? photo cell?
Tube!
Did you figure it out Jake?
Haven't cracked it, been working on his yamaha sy-2
From the Rocktron Velocity 300 manual-
"unbridged"
"150 watts per channel @ 4 ohms
75 watts per channel @ 8 ohms
37.5 watts per channel"
"bridged"
"300 watts @ 8 ohms
170 watts @ 16 ohms"
"These standard ¼" jacks provide outputs for Channel 1 to speaker cabinets. Do not connect these outputs
to a load of less than 4 ohms (or less than 8 ohms in mono-bridged mode). These jacks are used when
using the Velocity 300 in "BRIDGED" mode."
This makes no sense to me at all. If the amp puts out 300 watts total stereo(both channels total) at 4 ohms how can it put out 300 watts bridged at 8? The math seems wrong. Bridged is both channels combined together, no?
So if you have two 8 ohm cabs, one getting the signal from channel A and one getting the signal from channel B they are each only getting 75 watts BUT if you have them both hooked up to channel A bridged then the amp somehow tries to put out more than 300 watts and overheats because the load is 4 ohms? Where does this mysterious extra power come from for bridged mode? If I am understanding this correctly it seems like a very strange design. Why not allow the amp to put out 300 watts bridged at 4 ohms and 150 watts bridged at 8?
Quote from: liquidsmoke on December 05, 2012, 03:24:05 AM
From the Rocktron Velocity 300 manual-
"unbridged"
"150 watts per channel @ 4 ohms
75 watts per channel @ 8 ohms
37.5 watts per channel"
"bridged"
"300 watts @ 8 ohms
170 watts @ 16 ohms"
"These standard ¼" jacks provide outputs for Channel 1 to speaker cabinets. Do not connect these outputs
to a load of less than 4 ohms (or less than 8 ohms in mono-bridged mode). These jacks are used when
using the Velocity 300 in "BRIDGED" mode."
This makes no sense to me at all. If the amp puts out 300 watts total stereo(both channels total) at 4 ohms how can it put out 300 watts bridged at 8? The math seems wrong. Bridged is both channels combined together, no?
Bridged will be the two amps in series. In unbridged mode each output is 4 Ohm with 150 watts of power so you can connect a cab of 4 Ohm to each output and get 150 Watts to each, substitute these for 8 Ohm cabs and the power available halves (according to them, more likely it'd be around 2/3s).
Quote
So if you have two 8 ohm cabs, one getting the signal from channel A and one getting the signal from channel B they are each only getting 75 watts BUT if you have them both hooked up to channel A bridged then the amp somehow tries to put out more than 300 watts and overheats because the load is 4 ohms? Where does this mysterious extra power come from for bridged mode? If I am understanding this correctly it seems like a very strange design. Why not allow the amp to put out 300 watts bridged at 4 ohms and 150 watts bridged at 8?
It explicitly says do not hook up less than 8 Ohms to in mono bridged mode so you would not hook up two 8 Ohm cabs in parallel i.e. 4 Ohms. If you hooked them up in series you'd have 16 Ohm so you would get 170 watts between the two cabs. There is no mysterious extra power it can only ever put out 300 watts be that in mono or stereo so you've just fucked up the OT by hooking up two low of a load.
There's no way of allowing the amp to put out 300 watts bridged at 4 ohms as it is still two 150 watt 4 Ohm amps in series which will give you an 8 Ohm minimum load.
Quote from: moose23 on December 05, 2012, 05:27:04 AM
Quote from: liquidsmoke on December 05, 2012, 03:24:05 AM
From the Rocktron Velocity 300 manual-
"unbridged"
"150 watts per channel @ 4 ohms
75 watts per channel @ 8 ohms
37.5 watts per channel"
"bridged"
"300 watts @ 8 ohms
170 watts @ 16 ohms"
"These standard ¼" jacks provide outputs for Channel 1 to speaker cabinets. Do not connect these outputs
to a load of less than 4 ohms (or less than 8 ohms in mono-bridged mode). These jacks are used when
using the Velocity 300 in "BRIDGED" mode."
This makes no sense to me at all. If the amp puts out 300 watts total stereo(both channels total) at 4 ohms how can it put out 300 watts bridged at 8? The math seems wrong. Bridged is both channels combined together, no?
Bridged will be the two amps in series. In unbridged mode each output is 4 Ohm with 150 watts of power so you can connect a cab of 4 Ohm to each output and get 150 Watts to each, substitute these for 8 Ohm cabs and the power available halves (according to them, more likely it'd be around 2/3s).
Quote
So if you have two 8 ohm cabs, one getting the signal from channel A and one getting the signal from channel B they are each only getting 75 watts BUT if you have them both hooked up to channel A bridged then the amp somehow tries to put out more than 300 watts and overheats because the load is 4 ohms? Where does this mysterious extra power come from for bridged mode? If I am understanding this correctly it seems like a very strange design. Why not allow the amp to put out 300 watts bridged at 4 ohms and 150 watts bridged at 8?
It explicitly says do not hook up less than 8 Ohms to in mono bridged mode so you would not hook up two 8 Ohm cabs in parallel i.e. 4 Ohms. If you hooked them up in series you'd have 16 Ohm so you would get 170 watts between the two cabs. There is no mysterious extra power it can only ever put out 300 watts be that in mono or stereo so you've just fucked up the OT by hooking up two low of a load.
There's no way of allowing the amp to put out 300 watts bridged at 4 ohms as it is still two 150 watt 4 Ohm amps in series which will give you an 8 Ohm minimum load.
Ah okay, sort of makes sense now. Leaning towards a Carvin.
My Epiphone Valve Jr. just suddenly started making popcorn sounds instead of sweet rock sounds the other day.
Dead tube? Cap?
I've had amps make random popping noises every once in a while before but never like this.
Nothing plugged in:
[soundcloud]http://soundcloud.com/fallenshallrise/amp-deth[/soundcloud]
Something arcing, could be dud valve, could be a dud solder join, dirty socket. Not many valves to swap about to find if its that. I'd start there, toothbrush and alcohol to clean all the valve bases (interdental toothbrush to clean inside the sockets), then resolder bunch likely candidates on the board. That sounds like a valve to me though. Bash about with a plastic chopstick might tell you a bit more, but it seems fairly regular.
Anyone know where to source some parts for a SUNN Coliseum 300? A potentiometer 25K linear (according to the parts list I found on the webs) short shaft PCB mount with detent. It's the master volume. Also a PCB mount latching pushbutton with a black rectangular cap.
I have trouble navigating the big electronics suppliers websites. I suppose since I don't rightly know all of the details of the parts I'm after.
My Valve Jr. just crapped out as well. Heard static sounds like a dirty pot, then silence. Power tube remained lit, preamp tube was hidden by holder -- I pulled the preamp tube with the idea I would walk it over to the local shop for testing... but maybe I should take the whole amp there?
/wtf
Valve jr's are really cheap Chinese made so you wouldn't expect them to be the most durable. I just hope that it's one of those designs that eats tubes instead of a dead major component that scraps it.
Lol, you could replace every component inside a Valve jr. For less than 40 bucks.
Being lit only tells you the heater isn't broken in a valve, they can be wrong and still glow. Nasty low bidder valves in them are likelly the problem.
I swapped the tubes out on mine as soon as I bought it.
Sold it to Music-Go-Round and put the old ones back in, so I've got one used & one new Mullard EL-84 from a matched set if anyone needs 'em. I no longer have an amp that uses them.
It's great to have some people to run ideas past... so I finally got around to opening up the Valve Jr so I could have a look while it was making that popping sound and it's the tube for sure.
The heater lights up orange and then there's a blue/purple glow that fires on and off with the loud popping noise. If you tap the tube it makes the same popping noise.
RacerX I need those tubes so let me know what you want for them.
Quote from: fallen on December 10, 2012, 07:44:05 PM
It's great to have some people to run ideas past... so I finally got around to opening up the Valve Jr so I could have a look while it was making that popping sound and it's the tube for sure.
The heater lights up orange and then there's a blue/purple glow that fires on and off with the loud popping noise. If you tap the tube it makes the same popping noise.
RacerX I need those tubes so let me know what you want for them.
I dunno, maybe 10 bucks + shipping? I think I paid like 20 for the pair.
The one has probably 80-100 hours on it, & the other has never been used.
Quote from: Pissy on December 09, 2012, 11:35:23 AM
Anyone know where to source some parts for a SUNN Coliseum 300? A potentiometer 25K linear (according to the parts list I found on the webs) short shaft PCB mount with detent. It's the master volume. Also a PCB mount latching pushbutton with a black rectangular cap.
I have trouble navigating the big electronics suppliers websites. I suppose since I don't rightly know all of the details of the parts I'm after.
Here it is.
(http://i140.photobucket.com/albums/r32/EXKid1975/F3DC2EAE-281E-461E-B8F7-D3F221A0A0E5-1390-0000011214A9FAA2.jpg)
Also,
Notice that trim pot on the right that says "limit adj." I wonder what happens if it twist that thing!!!
Anyone got the schematic for an Orange Rockerverb 100? I called them and they hung up on me because I told them the build quality is atrocious on their amps.
Some come up on google image search: http://www.orangefieldguide.com/OFG_SCHEM/RV50C_sheet1.jpg
Was this US service call? By all accounts the phone service is pretty good from here, but I've never called them because people tend to not bring me shitty modern Oranges to look at, even though I keep hot glue in stock for them.
Quote from: Mr. Foxen on December 13, 2012, 10:08:18 PM
Some come up on google image search: http://www.orangefieldguide.com/OFG_SCHEM/RV50C_sheet1.jpg
Was this US service call? By all accounts the phone service is pretty good from here, but I've never called them because people tend to not bring me shitty modern Oranges to look at, even though I keep hot glue in stock for them.
Yep, the US office can smoke my cock, I'm not paying anyone to fix something that is more than likely something stupid and simple because I'm not a "certified Orange technician" or some shit. I'll figure it out, I've got a guy on it... :D
Quote from: SunnO))) on December 13, 2012, 10:37:49 PM
Quote from: Mr. Foxen on December 13, 2012, 10:08:18 PM
Some come up on google image search: http://www.orangefieldguide.com/OFG_SCHEM/RV50C_sheet1.jpg
Was this US service call? By all accounts the phone service is pretty good from here, but I've never called them because people tend to not bring me shitty modern Oranges to look at, even though I keep hot glue in stock for them.
Yep, the US office can smoke my cock, I'm not paying anyone to fix something that is more than likely something stupid and simple because I'm not a "certified Orange technician" or some shit. I'll figure it out, I've got a guy on it... :D
burn it to the ground, then build a OrMat from its ashes
Quote from: The Shocker on November 09, 2012, 05:56:27 PM
New old amp day.
Montgomery Ward GIM-9011A
(http://img.tapatalk.com/d/12/11/10/na6ugu8a.jpg)
(http://img.tapatalk.com/d/12/11/10/vy6a7ava.jpg)
(http://img.tapatalk.com/d/12/11/10/ja2y3aje.jpg)
(http://img.tapatalk.com/d/12/11/10/ybebejup.jpg)
(http://img.tapatalk.com/d/12/11/10/4uda2ype.jpg)
(http://img.tapatalk.com/d/12/11/10/beduby3u.jpg)(http://img.tapatalk.com/d/12/11/10/neveduzy.jpg)
(http://img.tapatalk.com/d/12/11/10/3emanaqe.jpg)
Came with about 10 of these:
(http://img.tapatalk.com/d/12/11/10/qysu8a8e.jpg)
And the reason I posted here as opposed to new acquisitions:
(http://img.tapatalk.com/d/12/11/10/atabuqyq.jpg)
Any idea where it goes?
Quote from: Mr. Foxen on November 09, 2012, 08:11:06 PM
Gonna be a hunt the legs mission.
SunnJake finally got to this one. Says it sounds good but hasn't found where the cap goes.
Since I'm a novice at this stuff, the amp doesn't necessarily need that cap? I would think most all the components are in an amp for a reason.
So whatever happened to the cheap bastid that started this thread? Haven't heard a peep outta him for some time now...
Quote from: RacerX on December 29, 2012, 03:35:53 PM
So whatever happened to the cheap bastid that started this thread? Haven't heard a peep outta him for some time now...
hemi? i think he has retreated to some sink hole in the middle of illinois to demo some new stoner rock jams . . . methinks, at least.
My 35 year old Randall s/s has developed a quiet yet obvious 60 Hz hum (it goes away w/ amp volume @ zero)....is this indicative of slowly failing capacitors (or such) ?
Quote from: Metal and Beer on February 03, 2013, 11:55:51 AM
My 35 year old Randall s/s has developed a quiet yet obvious 60 Hz hum (it goes away w/ amp volume @ zero)....is this indicative of slowly failing capacitors (or such) ?
Yup, model and year?
yea recap every 25-30 years
Sunnjake, update on the Montgomery Ward? Required any major repairs?
It's old and it sounds unique, but works fine, but is noisy because they have lights running off the AC lines.
Is 24 AWG too light for footpedal applications? 18-22 is called for, but I was thinking of using old ethernet wire, if it's not too thin...
That's too baby ass IMO. Metaldave, if you need parts lemme know, i got the hookup
(as some of you already know) I'm running a mini SS class D 350 watt bass head for guitar into 6 speakers(2 eight ohm cabs, each cab rated at 300 watts). Guitar is in B and I use a ton of distortion from a pedal. At high volume levels with more low end dialed in than I normally use weird stuff happens. The volume will kind of pulse down and back up repeatedly when I let heavy power chords drone. Is this the speakers failing or not being able to properly reproduce the low end? Fortunately I don't need that much low end in my tone so I have it dialed back enough to avoid said pulsing but I would like to understand what I'm hearing when I do have the low end cranked more. Oh yeah, the 2x12 has Eminence Swamp Thangs and the 4x12 has unknown blank 75 watt speakers.
Quote from: liquidsmoke on March 07, 2013, 10:59:29 PM
(as some of you already know) I'm running a mini SS class D 350 watt bass head for guitar into 6 speakers(2 eight ohm cabs, each cab rated at 300 watts). Guitar is in B and I use a ton of distortion from a pedal. At high volume levels with more low end dialed in than I normally use weird stuff happens. The volume will kind of pulse down and back up repeatedly when I let heavy power chords drone. Is this the speakers failing or not being able to properly reproduce the low end? Fortunately I don't need that much low end in my tone so I have it dialed back enough to avoid said pulsing but I would like to understand what I'm hearing when I do have the low end cranked more. Oh yeah, the 2x12 has Eminence Swamp Thangs and the 4x12 has unknown blank 75 watt speakers.
liquid, I am not sure why, but it seems like you have the most problems of anyone with your setup. How loud are you running this thing?
are you sure the speakers are in phase?
My knowledge of such things is limited/none but it sounds like the description of blocking distortion described here:
http://www.aikenamps.com/BlockingDistortion.html
im not sure that would be blocking distortion Moose since he is running a SS amp its much less prone to that problem but it could happen. I would think its more like a speaker issue
The pulsing phenomenon only happens when I turn the bass up more than usual. I run very loud but not as loud as for example some folks who use two 100+ watt tube heads into a full stack.
Finally got my matching 2x12 the other day and after that is a bit broken in I'll crank the bass up at high volume again and see how it handles. It definitely could have been a phasing issue with the different cabs I was using before.
This is just me being curious as we have a bass player and I try not to compete too much on the low end of the spectrum. That bass knob is fun to crank sometimes though. I know they vary but for B tuning so far I think bass amps are the bees knees into guitar speakers, for guitar.
A bass amp doesn't play nice with a guitar cabinet when you crank the bass control?
No way.
Quote from: RacerX on March 12, 2013, 02:25:55 PM
A bass amp doesn't play nice with a guitar cabinet when you crank the bass control?
No way.
Quote from: liquidsmoke on March 07, 2013, 10:59:29 PM
I have it dialed back enough to avoid said pulsing but I would like to understand what I'm hearing when I do have the low end cranked more
Quote from: liquidsmoke on March 11, 2013, 09:26:17 PM
The pulsing phenomenon only happens when I turn the bass up more than usual.
...This is just me being curious as we have a bass player and I try not to compete too much on the low end of the spectrum.
I have a noisy Thunderverb 50 all of a sudden! Its making a very annoying buzzing sound that gets louder when i get near it. It was not like this last week when i used it. I did transport it fro one practice spot to another but it wasnt dropped or bumped. My troubleshooting has been this:
1. Swapped out all of the cables to see if i had a bad one- done and good
2. took my pedal board out of the line and went direct guitar to amp- done and good
3. changed wall outlets to see if i had some dirty power happening- done and good
4. changed guitars to see if it was a pickup- done and good
Any ideas what it could be? I am no tech, but i like to have an idea of what I'm getting into when I take it to one! Thanks
Quote from: hayseed on March 13, 2013, 08:44:30 PM
I have a noisy Thunderverb 50 all of a sudden! Its making a very annoying buzzing sound that gets louder when i get near it. It was not like this last week when i used it. I did transport it fro one practice spot to another but it wasnt dropped or bumped. My troubleshooting has been this:
1. Swapped out all of the cables to see if i had a bad one- done and good
2. took my pedal board out of the line and went direct guitar to amp- done and good
3. changed wall outlets to see if i had some dirty power happening- done and good
4. changed guitars to see if it was a pickup- done and good
Any ideas what it could be? I am no tech, but i like to have an idea of what I'm getting into when I take it to one! Thanks
Caps.
Those amps are fickle and shitty, could be a number of things. Have you gotten shocked yet?
No shocks yet. Just a hum when I'm at a distance and a loud buzz when I get close.
Quote from: hayseed on March 13, 2013, 08:44:30 PM
I have a noisy Thunderverb 50 all of a sudden! Its making a very annoying buzzing sound that gets louder when i get near it. It was not like this last week when i used it. I did transport it fro one practice spot to another but it wasnt dropped or bumped. My troubleshooting has been this:
1. Swapped out all of the cables to see if i had a bad one- done and good
2. took my pedal board out of the line and went direct guitar to amp- done and good
3. changed wall outlets to see if i had some dirty power happening- done and good
4. changed guitars to see if it was a pickup- done and good
Any ideas what it could be? I am no tech, but i like to have an idea of what I'm getting into when I take it to one! Thanks
I opened it up today and did the pencil test with the tubes. V1 (far right, channel a&b, ECC83 ) was noisy as was the position above it (fx loop, 12AT7) though not as bad. I switched tubes between v1 and v3(far left) and it helped with the buzz a little bit but v1 was still microphonic when i tapped it. Could that be a tube socket gone bad?
thanks
Just swap out all the preamp tubes, sockets can't go microphonic.
Thanks. I will order a new set today. There is a tube for the reverb and fx loop(ecc81). Should I include change those as well? Not sure how much those positions affect the rest- I don't use the fx loop anyway.
Have an orange rockerverb 100 that just died on me the other day. Was playing at about half volume, and suddenly it went quiet. No crackle or any other bad sign, just stopped making noise completely. Tried different cab and cables to no avail. Power seems to be present in amp i think.. didnt really spend too much time on it, just plugged into different amp and moved on. Any ideas, or common things to look for? And yes i know everyone says these are cheap pieces of junk.
Phase inverter and screen grids are the first thing to check. Take all the shields off the preamp tubes and make sure they are all firing. I just did this with the same piece of ass amp.
Hey ya'll,
I just picked up a Sunn 200S (late 60s). It's got 2 speaker inputs -- one is labeled "16 ohms" and the other is "External Speaker 8 ohms." So my understanding of my basic cabinet options for this amp are as follows:
1. Obviously, a 16 ohm cab into the 16 ohm input;
2. An 8 ohm cab into the "External Speaker" input. I'm under the impression that it's okay to use the "external speaker" input by itself with this amp. Please correct me if I'm wrong. I know with some amps you are not supposed to do this;
3. Two 16 ohm cabinets (1 in each input). My understanding is that plugging into the 8 ohm "external speaker" input switches BOTH inputs to 8 ohms. So, 2 16s = 8ohm load.
Do I have this right?! Also, I am planning on using this for guitar. If anyone is familiar with this amp and can offer tips/suggestions, please do! Thanks for reading.
Neg, you can daisy chain two 16s to the 8 ohm tap, but not use both taps at once. There's no weirdo switching, it's the 16 ohm tap from the tranny to one jack, and the 8 to the other.
Shit okay gotcha. So then I'm assuming it's still okay to use the 8 ohm "external" jack by itself with an 8 ohm cab? Just want to be absolutely sure. Still learning about all this stuff...
yesh! perfectly fine!
Awesome. Thanks for the help, man.
During my move the square pilot jewel somehow popped off my Super Bass (68-69). Any of you techey types knows if there is a difference other than the price between the assembly form Mojotone and the one from AES. They both say genuine Marshall old style.
Are there any dimensions on the websites? I can't seem to find any.
0.44" Length x 0.44" Width x 0.27" Depth-AES
Dimensions: 7/16 x 7/16" x 1/4" Deep-Mojotone
Same size, give or take. I assume they are the same part, diff outlet.
Just set my pedal board up again after not being used for some time, and everything looks good until turning on a pedal (any pedal), which results in the amp going silent. The amplifier is a blackstar HT1 amp and the power supply is a one of those power bricks (10 plugs or so).
I have tried individual pedals, and I'm still getting this. Also, the pedals indicate that they are getting power as supposed to (it is by the way also possible to replace a fuse in the power supply).
Any idea what could be causing this?
You're telling me it does this with any pedal powered by the brick, or any pedal? Eliminate all possible factors. Make sure it isn't the amp, first, so we can start eliminating shit on the board.
The amp works when the pedals are in bypass, none of the pedals work when connected to the brick, and the fuse in the brick is fine. Gonna test a few different combination of cables before starting to test the pedals with batteries.silent when turning on pedalsilent when turning on pedal
Quote from: aowron on April 14, 2013, 03:04:15 PM
The amp works when the pedals are in bypass, none of the pedals work when connected to the brick, and the fuse in the brick is fine. Gonna test a few different combination of cables before starting to test the pedals with batteries.silent when turning on pedalsilent when turning on pedal
Ok, found the cause: turns out it was one of my cables (of course the one I never tested because of "hey, it's a planet waves cable that looks like new, that fucker can't be broken"). Kind of a weird problem though; any idea why that happens?
Edit: Eherm... Turns out I put the cables in the wrong in/outputs on the Pharaoh... *cough* I mean, checking the most obvious reason to why it wouldn't work first would really stupid, now wouldn't it? (notice the irony; yes, irony never work on teh internets)
Well, thanks for the help anyway!
What's the easiest way to split the signal between a guitar head/cab and a bass combo amp at the same damn time?
Quote from: Dr. Skeeter on April 23, 2013, 03:37:18 AM
What's the easiest way to split the signal between a guitar head/cab and a bass combo amp at the same damn time?
Have you got a Boss Tu2 tuner?
a y cable is the easiest way but probably results in ground loop hum. One signal generally needs to be transformer isolated from the other to reduce the problems of ground loop hum
I've been using a Radial Big Shot for quite a while. Like Dunwich said, it has an iso transformer among other features. They're about 70 bucks.
Line out on Sansamp or boss TU2 are pretty standard. The super ahrd on and thus most clones have two outs, the buffer sorts impedance issues arising from connecting two things.
Seeing as i'm a drummer i'm like wtf right now, but it sounds like we're about to get a boss TU2 tuner. I've heard that before anyways. Thanks guys.
Speaker malfunction question:
On the last rehearsal, a speaker from a 210 cab started to break up really really soon, it sounded like AIDS so we unhooked the cab from the amp and unscrewed the grill cloth roster (it's one of those Peavey cabs with silver colored strips on the side), the speaker itself looked fine, the cone isn't torn so my question is: what could it be? Fixable or just get a new speaker? I didn't unhook the speaker itself because it didn't seem to budge, even when I unscrewed it..
Quote from: MichaelZodiac on May 10, 2013, 10:27:53 AM
Speaker malfunction question:
On the last rehearsal, a speaker from a 210 cab started to break up really really soon, it sounded like AIDS so we unhooked the cab from the amp and unscrewed the grill cloth roster (it's one of those Peavey cabs with silver colored strips on the side), the speaker itself looked fine, the cone isn't torn so my question is: what could it be? Fixable or just get a new speaker? I didn't unhook the speaker itself because it didn't seem to budge, even when I unscrewed it..
If you're positive it's not ripped, press on the cone and listen for rubbing sounds. Next take a volt meter and check the impedance. It should read slightly lower than the spec. Also when you hook the leads of the meter up to the speaker, you should hear a few pops of white noise.
Check really good for a rip though. Is the cone seated completely to the frame around the outside? That's not a rip, but it will fart like my dog after eating my 2 year olds chili off the high chair.
Here's my current dilemma.
(http://i140.photobucket.com/albums/r32/EXKid1975/42588A6B-4D0E-463A-B9E4-B5E871474C05-2192-0000035DAA1CD0B6_zps971bbe4e.jpg)
I bought a group of pedals and this one has a fully disclosed issue. Fried components.
That fried resistor I've pulled off the board and measured 79k. The capacitor next to it was puffy and I pulled it as well. It measured 110mF, half of its spec (220mF).
This is part of the power supply circuit.
I don't trust my reading of that resistor, so without a schematic I'm left to guess at the true value. The capacitor is easy enough. So for the resistor... 100k?
What effect is it and what values are the three caps, two look like 22uF? Good chance it could be either a 100R current limiter if it's inline with the supply line or it could match the one beside it and be used as a voltage divider for a bias supply Vb.
220uF caps. The resistor beside it (if I'm up to snuff on my resistor codes) is 330k. Red-red-black-gold.
It's a tech 21 Boost DLA.
I have been Having trouble with my 800.
Noticing radio static/crackle after I hit a note. Otherwise, it's dead silent.
It's not the guitars or any of the cables.
I am guessing it's either the tubes, dirty sockets, or the filter caps.
Would a microphonic tube cause this? Try lightly tapping a tube to see if any of them transmit the tap through the amp.
Take the head off the cabinet and try it. That should tell you if something's loose also.
Tried the pre-amp tubes and that's not it.
What's the darnedest thing is that after ten-fifteen minutes of it being on, after I let it warm up for about ten-fifteen minutes, the crackle/static noise that happens after I hit a note dissappears.
Sounds like a bad solder joint. When the amp heats up the joint expands. First thing I would do is give it the old chopstick test.
+1 on being a bad joint. Chopstick might give a clue as to where, but I'd go and resolder pretty much everything, chances are it wasn't a great job to start with.
I did the chopstick method last night and sure enough, it is the solder joint(s).
Looks like she is going to the shop next week. I guess more of a reason to buy another head or tube combo.
Re-flow the joint if you found it.
My V-4 keeps blowing power tubes, generally taking out smaller components with it, my tech has it biased for jj 6550's, but I think that's what's causing the problem. Would 7581's be a viable alternative? I like the clean headroom of the 6550 but I don't think my amp likes them.
Full going over to find actuual problem, rather than throw more valves at it. Including if you cab is the problem.
Oh of course, I brought it to my tech this morning and while we checked it out then, he's going to over it more thoroughly. My cabs shouldn't be an issue, they're sunn/fender reissue 4x12s and have no problems. From what it looks like the JJ's and sovteks I've tried don't handle the voltage of the v-4 well and fail easily.
it was designed to use 7027a, but there is no true modern equivalent for them in terms of voltage specs.
Quote from: dunwichamps on May 29, 2013, 01:22:40 PM
it was designed to use 7027a, but there is no true modern equivalent for them in terms of voltage specs.
I just put a set of JJ-7027A tubes in a V-4 on Friday. They worked just fine. I've had 5881, 6L6GC, 6550, and modern 7027A tubes all work fine in a V-4 with just a little bit of modification. I'm sure that I could get other tubes such as KT77 or EL34 to work as well.
Quote from: FullCustom on June 04, 2013, 10:35:23 AM
Quote from: dunwichamps on May 29, 2013, 01:22:40 PM
it was designed to use 7027a, but there is no true modern equivalent for them in terms of voltage specs.
I just put a set of JJ-7027A tubes in a V-4 on Friday. They worked just fine. I've had 5881, 6L6GC, 6550, and modern 7027A tubes all work fine in a V-4 with just a little bit of modification. I'm sure that I could get other tubes such as KT77 or EL34 to work as well.
they will function but it puts stress on the screens. The screen voltage is overspec and so its more liable to burn out the power tubes. Dropping the screen voltage down and bumping up each screen resistor to 1k 5W will help to prevent this problem.
I got the amp back about a week ago but have been to busy to take it to the space. Apparently there was a diode (I forgot where he said exactly, bias supply maybe?) That was letting over a large amount of voltage, so that could have been the culprit. It also now has a quad of Sylvania 6l6gcs that were rebranded for mesa that I got for a cool 100 bucks.
i recently bought a brand new fender deluxe reverb reissue, and after playing it a few times it´s developed this nasty glassy rattle that occurs everytime i play an E (on any string or octave).i´ve been looking through a lot of threads on other message boards on this and haven´t found a solution yet , or someone who has the exact same problem for that matter.
any advice would be appreciated :-[
Dead speaker or loose speaker.
Get a friend to poke around on the thing until you find the offending physical issue. All while you play a Scott Pilgrim E note.
Did you buy it new or used?
i bought it brand new
the rattle also pops up at very low volume ???
Take that shit back yo.
Quote from: sheikyerbouti on June 11, 2013, 08:37:57 AM
i bought it brand new
the rattle also pops up at very low volume ???
If it's less than 30 days old just send it back to the store you got it at. If it's less than 90 days old even tubes are still under warranty. Fender's warranty and service are really good.
Does the type of magnet in a humbucking pickup have any bearing on how much it hums/feeds back? Alnico II, V, ceramic?
I have an old univox amp that has a blown output transformer. It has 2, 4 and 8 ohm taps. Is it possible to replace the OT with a transformer with 4, 8 and 16 ohm taps?
yes, just need to find the "right" primary for the power tube setup you have and adjust which tap the feedback is coming off of.
Sorry if this has been touched on before. I did a search but saw nothing...
I'm going to retube my OR120. I've had a tech do the bias for me in the past but this time I'm going to do it. As you may know, these have no standby. How does this affect the boasing process? The step-by-steps I've found heavily noted what to be done in and out of standby, so how will this change things?
Thanks!
in order to bias the amp, it needs to be completely on as you need to measure plate voltage and cathode current
Since it looks like the preamp tubes are almost worn out in my amp (they have gotten microphonic once; just squaling making the amp unplayable), I'm thinking of replacing them, and at the same time resolder one of the input jacks. This does though lead me to the question: what is required to actually drain the caps? I've seen quite a lot of different answers regarding this, although I found this today: http://www.youtube.com/watch?v=sw9KnSFy3Fs, where it looks like the tubes basically will discharge just by running the amp hot, and then turning it off.
Also, it seems like my amp was not as loud as usual last time it was used; my 330watt hybrid bass amp could easily keep up with it (and the amp this is regarding (the guitar amp) is a Laney GH50L connected to a 4x12). Could this be due to crappy preamp tubes or could it mean that I also need to replace the power amp tubes?
A bit of history on the tubes in the amp: When I bought it, the power amp tubes had recently been replaced (Mullards; although newly made (thus made in the Sovtek factory in Saratov), but were apparently expensive as hell), while the preamp tubes were some old sovteks from the previous owner's JCM2000, thus, this leads me to believe that the EL34:s should have some time left since the amp only has been used in a Jam Room for about a year, while the preamp tubes probably are worn out.
Anyone familiar with early 70s Ampeg 2x15s? I see one going for a fairly decent price here but curious if they're worth it or should I just stick to my plan of building myself a Sunn215B replica. Will be used on bass with a Sound City 120 MK4
Quote from: dunwichamps on July 11, 2013, 08:27:01 PM
in order to bias the amp, it needs to be completely on as you need to measure plate voltage and cathode current
I think what he is referring to a method of measuring bias current by placing your meter across the open standby switch. Some old-heads would do Fender amps that way. It does work, I've tried it.
How much distorting can Eminence Swamp Thangs take before they begin to become damaged? At practice/gig volume really weird shit(strange pulsing that sounds bad) starts happening if I have too much low dialed in and I suspect that no damage will occur before that point but I'm not completely sure. I want as much thick low end/low mids as possible even if it's ridiculous for guitar.
A bass player friend ran her Ampeg B2R with a 4ohm and 8ohm cab together. The amp's min load is 4ohm, so she roached something. What ususally takes the shit in that situation and is there anything that can be done?
Any number of things can pop in that situation... They will be apparent when you open it...
The swamp thangs shouldn't be distorted or fucking up at alll, they're ridiculously resilient
Hey, thanks Jake))). I'm aware of thems lethal voltages and a little askeered of opening it up. Are there some common failures? Could you perhaps list a few, from least to worst case scenarios? Will you come over and fix it? I give good backrub.
Was there smoke or any weird smells. if not maybe a fuse on the board? Check easy shit first.
B2 is solidstate, so not very high voltages, enough to make you learn to not touch thing things any more though, unless you have a dicky heart. Blown output transistors is what you get, but it might have thermal protection or somehting else that will kill it before hard bits are damaged. They are a proper ballache to get inside and see anything useful though.
Merci Beaucoup.
Quote from: SunnO))) on July 27, 2013, 11:10:40 AM
The swamp thangs shouldn't be distorted or fucking up at alll, they're ridiculously resilient
That's good to hear. They are rated at 150 watts each too. So far I love them. I may try to push em a little harder but as I was explaining weird pulsing tends to occur when I have too much bass dialed in. I am using a bass head but my Ampeg SS guitar head(would have worked fine for bass actually) had loads of low end to spare and could also create such strange bad sounds.
Quote from: liquidsmoke on July 28, 2013, 04:57:29 AM
Quote from: SunnO))) on July 27, 2013, 11:10:40 AM
The swamp thangs shouldn't be distorted or fucking up at alll, they're ridiculously resilient
That's good to hear. They are rated at 150 watts each too. So far I love them. I may try to push em a little harder but as I was explaining weird pulsing tends to occur when I have too much bass dialed in.
Sounds like the simplest solution to the "weird pulsing" is don't dial in "too much bass."
Quote from: RacerX on July 28, 2013, 08:58:20 AM
Quote from: liquidsmoke on July 28, 2013, 04:57:29 AM
Quote from: SunnO))) on July 27, 2013, 11:10:40 AM
The swamp thangs shouldn't be distorted or fucking up at alll, they're ridiculously resilient
That's good to hear. They are rated at 150 watts each too. So far I love them. I may try to push em a little harder but as I was explaining weird pulsing tends to occur when I have too much bass dialed in.
Sounds like the simplest solution to the "weird pulsing" is don't dial in "too much bass."
:D
So I bought a cheap guitar online... and it seems like the volume comes and goes. It will play normally for about a minute, and then for a minute the volume will drop (a lot). Then a minute later, back up to normal.
What could be causing that? It's not my amp, I tried it with a different amp. Same problem.
Since the tech seems to be out, my Magic 8-Ball sez the problem is buying a cheap guitar online.
Shitty pots, honestly.
Quote from: Lumpy on August 13, 2013, 06:40:19 AM
So I bought a cheap guitar online... and it seems like the volume comes and goes. It will play normally for about a minute, and then for a minute the volume will drop (a lot). Then a minute later, back up to normal.
What could be causing that? It's not my amp, I tried it with a different amp. Same problem.
This might be pickup height. Move them down a turn or two and see what happens.
Actually, what is the pickup configuration? Does it do that across all of the pickups? If so, then it might be a string/nut/bridge thing - likely not pickup height. Change the strings and see if it clears up - paying attention to the nut and bridge contact points on the strings and perform some freshening up there. If not, then look at the pickup height.
The jack, and the pots can cause this too, but I'd look into the physical stuff first, then open up the control cavity and look for cleaning up opportunities (wire length, solder joints, contact cleaner in the pots, jack function, shielding).
Hope this helps. Cheap guitars can work great, but upon receipt, this kind of crap is the rule, not the exception.
The bridge is terrible, I think it's pressed metal. It has little divots where the strings ride (you get a choice of 3 divots per each string). The nut is also pulling up.
For pickups, it's two... Strat style, with no switch. Just a volume and a tone knob. I'm not even sure if I can adjust the height.
I will change the strings right away. Seems like they suck.
I need new tubes in my record player console in the house. 6BQ5 which is equivalent to an EL84 I think. Any suggestions? I guess I want the highest headroom possible given its a home stereo.
?
Try EL84Ms.
Where can I get case corners (protectors)??
I'm looking for brick and mortar retail stores -
The internets want more for shipping than the corners themselves.
Is there Ace Hardware up there? Any store that has grab bins of shit should have them.
I forgot that ACE is the Place with the Helpful Hardware Man.
The local store has a couple store cats.
They had plenty of fancy brass.
I'm just looking for basic chrome. The search continues.
Bummer, what are they going on?
I'm building a wooden cart for my buddy's work truck.
It's wheeled and will be loaded off and on the truck, as well as around whatever locations we end up at.
Just thought protecting the bottom four corners would be nice.
Do the whole bottom edges in thin angle iron or galvanized.
Q1) What Marshall circuit does the Traynor Bass Master most closely resemble? I'm too spaced out on pain killers (another round of dental surgery) and Wild Turkey to google this shit.
Q2) What are the differences in the circuitry and what is the sonic repercussions of said differences?
So I desperately want to move the standby on my earth Superbass from the rear of the amp to the front. What is the most effective way to drain the caps so as to ensure I don't kill myself? Anything else to keep in mind?
Bleeder resistor if they are huge. If not, alligator clips and a bit of wire, clip one end to the chassis, then touch the cap.
Amp attached to speaker cab but amp not plugged into wall, turn on both switches for 15 minutes, speakers should drain caps. This is prolly the least intrusive way but just to be sure I use a meter set to 1000vdc. There's always just the screwdriver method.
Quote from: RAGER on November 19, 2013, 06:24:45 PM
Amp attached to speaker cab but amp not plugged into wall, turn on both switches for 15 minutes, speakers should drain caps. This is prolly the least intrusive way but just to be sure I use a meter set to 1000vdc. There's always just the screwdriver method.
I've practically welded a screwdriver to an SVT chassis before.
I made up a discharge tool that is crocodile clips on a resistor around 20k or so, clip that on the relevant place and sorted.
Quote from: RAGER on November 19, 2013, 06:24:45 PM
Amp attached to speaker cab but amp not plugged into wall, turn on both switches for 15 minutes, speakers should drain caps. This is prolly the least intrusive way but just to be sure I use a meter set to 1000vdc. There's always just the screwdriver method.
speakers wont drain the power supply, they are electrically isolated from the amp via the OT. The only way the power supply is going to drain over time is to have a resistive path from one of the supply caps to ground.
Check this crazy new tuner out! Pretty rad:
http://techcrunch.com/2013/11/20/you-can-tune-a-guitar-but-you-cant-tune-a-fish-with-roadie/
Quote from: RacerX on November 20, 2013, 01:36:42 PM
Check this crazy new tuner out! Pretty rad:
http://techcrunch.com/2013/11/20/you-can-tune-a-guitar-but-you-cant-tune-a-fish-with-roadie/
Knowing which way to turn the machine head is something I can understand needing a device to tell you. The actual turning it part, not so much.
I'm not down with anything that requires an iProduct to operate.
Hi:
(http://i1164.photobucket.com/albums/q575/breakout79/tumblr_m53jnnANQ21ruzbfio1_500_zpsadb0b7f1.jpg)
I'm researching Sleep from back in the 90s and am curious as to what a Matamp Slave unit is used to perform. Amplify the amplifier? I've performed a search of the jam room and poked around Google. Nothing seems to be explained out too well regarding these slave units for the newby's understanding.
B
It's just a power section. Basically the amp, minus a preamp.
Yeah, its just what they called power amps before people lost the ability to understand context before they got offended.
It's all shrouded in mystery.
Quote from: Mr. Foxen on January 11, 2014, 10:30:26 PM
Yeah, its just what they called power amps before people lost the ability to understand context before they got offended.
You're sassy tonight.
Tonight?
You "slave" the slave unit off the "master" or preliminary amplifier's pre amp stage so you get essentially the same pre amp sounds going to more than one power section and their respective cabinets.
Also google skills are extremely lacking as I found pages of links when I searched "slave amp".
http://www.seymourduncan.com/blog/tips-and-tricks/obey-your-master-the-art-of-amp-slaving/
I Googled "Slave Unit" and not "Slave Amp" as that's what's on the picture I provided. That probably explains the disparity. Thanks for that link, by the way. I'm starting to maybe slave my Blackstar HT 20 to the Orange OR15 head. It would be cool to hear that particular preamp stage through the EL34s of the Blackstar. Both amps have effects loops.
Nobody thought It was funny when I called my slave amp "N-word Marshall"
Quote from: SunnO))) on January 12, 2014, 09:33:37 AM
Nobody thought It was funny when I called my slave amp "N-word Marshall"
I guffawed.
Alright, so after reading up, I understand that I can take my Orange's FX send and route that to the Blackstar's FX return. The master amp (Orange) will still need a speaker load, right? If I don't have an extra cab, can I just remove the EL84 power amp tubes? Am I still demonstrating no grasp of this topic?
You do not want to do that.
You can probably run the other amp with no power valves, not much bad can happen, but without the current draw from them, possibly some odd stuff can happen, voltages not being quite right and such, generally that would only upset power valves though.
Thanks for the advice. I'll put a LOT more study into this subject and perhaps befriend an electrical engineer before ever attempting to cascade amps. Back to the drawing board.
Cheap Peavey cab, go ahead, they're on Craigslist... W
Quote from: Boguspierre80 on January 12, 2014, 12:26:43 PM
Thanks for the advice. I'll put a LOT more study into this subject and perhaps befriend an electrical engineer before ever attempting to cascade amps. Back to the drawing board.
Current electrical engineers might have no clue about the function of valves amps though. There was a Klipp on ebay that had been got to by a current electrical engineering student and they utterly fucked it.
http://www.mojotone.com/guitar-parts/Guitar-Capacitors/Volume-Mod-for-Guitars#.Utv7SGcanIX
are the cap and resistor bi directional?
wee ceramic caps aren't polarized.
if its a slave then its just the input of the phase inverter of a GT120 with a volume pot on the input to control the volume. Simple as that
Is it safe to send a 3V +10dBV preamp signal to a power amp with a 1.23V +4dBm input sensitivity?
These numbers are straight from SoundTech PS802 and Peavey Rock Master manuals. +10dBV just seems exceptionally hot.
The other possibly worthy Rock Master output is 1V 0dBV which I assume is fairly weak for 1.23V +4dBm.
Another question would be how to run the PS802 in stereo with only one +10dBV output jack but one of my cabs also has a through output so I'm assuming I could chain them together and run the amp in bridged mode however that would I think be 800 watts mono 4 ohms which isn't listed in the manual as being okay. Each cab is 8 ohms and the PS802 manual lists the following:
Stereo 4 ohm 400W+400W
Stereo 8 ohm 230W+230W
Mono 8 ohm 800W
Will I be forced to run the cabs chained through only one channel? That would I believe be a 4 ohm 400 watt load which should be plenty of power.
I don't want to fry anything. I've read both manuals and Google searched but I'm still unsure.
(http://medias.audiofanzine.com/images/normal/peavey-rock-master-tube-preamp-421027.jpg)
(http://www.fdwcorp.com/common/products/original/153173.jpg)
I don't dig the binding post output connectors(edit: just heard about banana clips!) but the price was very right for so much power. Some bass players use this amp so I'm hoping it will sound okay for guitar.
ignore
^ got this business resolved I think. Going to use the 3V output into one channel and chain the cabs. It's still 400 watts which should be plenty.
I just picked up a Univox model 1236 amp. It has one speaker out but no output impedance listed. How do you determine the output impedance of an amp?
Quote from: beerrhino on February 16, 2014, 12:24:16 PM
I just picked up a Univox model 1236 amp. It has one speaker out but no output impedance listed. How do you determine the output impedance of an amp?
Its pretty much run it into a load and see how it behaves on a scope, learning how mismatches sound by ear is prob a bad plan. If its all working right, start at 4ohm and see if it sounds right, big of goggling suggests may well be 4ohm and too low load on a tap is tone compromise not valve damage.
Quote from: beerrhino on February 16, 2014, 12:24:16 PM
I just picked up a Univox model 1236 amp. It has one speaker out but no output impedance listed. How do you determine the output impedance of an amp?
If I were to run into an issue like this with a 70's tube amp, I'd assume 8 ohms and go on with life.
hey liquid, don't freak over those I/O numbers on those amps. those are max values if you turn up all the way. and the input sens just says that is the value that maxxes the amp to full rated output.
I would try all combos and see how the units work the best. if you go high gain and hi input , you have a tiny range of useable input values before the amp max's out
the higher the gain, the higher the noise floor. so if you aren't using it, may as well back off and back the noise floor off too
you wont know what gain ranges suit your uses the best until you try them all.
the only way you can fuck up is if you short the speaker outs
in fact a lot of amps have gain controls so you can turn to something less than max gain based on what the pre signal is going to be
also somehow sharply cutoff deepest bass frequencies if you can. rumble just wastes power and muddies your sound. that will leave a ton of extra power for the music content
***regarding loading that amp down. I would just wire that for stereo like it is set up. you will also be evenly using the circuit as it was really designed. a mono signal stays mono, even through stereo output. stack the 2 speakers to kill the stereo field to a mono speaker system. I have adapters for anything audio. I would split my peavey output and feed both amp inputs with the split mono signal. I like symmetry. the freak in me demands symmetry
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can you see any part number on th eoutput transformer or have you found the mfr specs online yet. the info is out there to determine exactly what the output impedance is for that transformer
nm , I looked. the op transformer has 8 ohm and 4 ohm taps on a univox 1236. be very careful with that amp, there are some seriously high voltages set up in there. I don't like it already.
Hi everyone, first time poster here. Does anyone know a tech that's handy and will work on Beta Leads? I asked John McNeece if he'd look at it awhile ago and he said that he has officially retired from repairing them.
Yep. He fixed all mine and hates them so much. He was my local tech for years.
I own several. They suck to work on.
Quote from: jibberish on February 25, 2014, 06:01:38 AM
hey liquid, don't freak over those I/O numbers on those amps. those are max values if you turn up all the way. and the input sens just says that is the value that maxxes the amp to full rated output.
I would try all combos and see how the units work the best. if you go high gain and hi input , you have a tiny range of useable input values before the amp max's out
the higher the gain, the higher the noise floor. so if you aren't using it, may as well back off and back the noise floor off too
you wont know what gain ranges suit your uses the best until you try them all.
the only way you can fuck up is if you short the speaker outs
in fact a lot of amps have gain controls so you can turn to something less than max gain based on what the pre signal is going to be
also somehow sharply cutoff deepest bass frequencies if you can. rumble just wastes power and muddies your sound. that will leave a ton of extra power for the music content
***regarding loading that amp down. I would just wire that for stereo like it is set up. you will also be evenly using the circuit as it was really designed. a mono signal stays mono, even through stereo output. stack the 2 speakers to kill the stereo field to a mono speaker system. I have adapters for anything audio. I would split my peavey output and feed both amp inputs with the split mono signal. I like symmetry. the freak in me demands symmetry
---------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------
can you see any part number on th eoutput transformer or have you found the mfr specs online yet. the info is out there to determine exactly what the output impedance is for that transformer
nm , I looked. the op transformer has 8 ohm and 4 ohm taps on a univox 1236. be very careful with that amp, there are some seriously high voltages set up in there. I don't like it already.
Just seeing this post now. I'm not currently using this amp but hope to in the future bridged into an 8 ohm high wattage handling bass cab with my baritone. Need to get the cab first and get off my ass and put some serious time in on the baritone.
Quote from: SunnO))) on April 04, 2014, 11:12:44 PM
Yep. He fixed all mine and hates them so much. He was my local tech for years.
I own several. They suck to work on.
Talked to one of the Red Fang dudes one time and he said that every 3 months something broke in their Betas. Constant rotation through techs. No idea who they used though.
I can tell you that if their anything like this coliseum bass I have here, that A) it was ridden really hard for a long time - beer and smoke and club schmeg galore- and B) the circuit boards and ribbon traces have lots of small brittle opportunities to open. It IS a pain.
Coliseums are child's play compared to working on betas. You can actually trace the circuit in the Coliseum heads. The beta its like following a maze with pungee pits (the switching chip,) and an unfair amount of capacitors that can introduce wicked noise to the circuit. Im very lucky that mine have been pretty damn reliable.
I have a Washburn solidbody beater with S/S/SS pickups (so the humbucker is configured like 2 singles). I want to make this guitar into a noise machine (shrieks, screeches, etc). It barely feeds back unless I literally put the guitar right in front of the cabinet (and even then, results not guaranteed). What can I do to make this mild mannered entry level guitar into an uncontrollable ear-fucker? Un-ground the pickups?
On another forum (yes, I am dating other forums) they told me that swapping out pickups won't really do anything, and just put a couple of dirt pedals together in a row. That's what I'm doing (rat clone is last in line) and it's not that satisfying. For one thing, it makes the guitar sound muddy. I'm looking for "shrill and piercing". I'll try again this weekend with clean boosters, but I'm doubtful.
My old guitar player had an old Supro that would scream and howl in the most delicious ways. The guitar was on the verge of falling apart. He could get sounds from tapping on the pickups, etc. How can I disable my guitar to get results like that?
Pic of same (or similar) Supro model I'm referring to (I remember slider switches too, but not certain):
(http://www.vintageguitars.fr/media/supro-dualtone.jpg)
Similar if not exact model of Washburn ('rocker series'):
(http://www.guitar-museum.com/uploads/guitar/143/270286875796-2.jpg)
Please help me ruin my guitar.
The EHG feedback seems like humbuckers and loud tube amps, it's warm and howly. I'm looking for screechy single coils, more shrill and trebly.
Hey, where'd your post go? ???
Not that I'm picky... this guitar seems like a dud though, that's what I'm trying to say. Not very lively.
I'm gonna return it - "This guitar aint broken!"
Trying to make a recent model $60 budget guitar sound like a 60's vintage Japanese pawnshop score. Fool's errand, my specialty. :P
So on my SVT-II this solder trace from an electro cap burned thru. It connects to about 6 other things.
Can I solder a wire jumper to just one of the other traces to re-establish the connection, or do I need to do leads to all the parts?
(http://img.tapatalk.com/d/14/04/11/yzudebu8.jpg)
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Lumpy, what about treble boosters in combination with rat and a possible clean boost?
Cheap humbucker and lots of gain should do it.
Edit* An unpotted one.
Quote from: MichaelZodiac on April 10, 2014, 12:55:07 PM
Lumpy, what about treble boosters in combination with rat and a possible clean boost?
I already use a Screaming Bird (it's maybe not a true treble booster though, it may be more like an EQ). Gonna try the clean boost in the chain too...
Quote from: RAGER on April 10, 2014, 01:03:30 PM
Cheap humbucker and lots of gain should do it.
Edit* An unpotted one.
A different pickup was what I was thinking too. But the 'unpotted' might be the key factor. Maybe I should pull the existing HB, and if there's any wax, scrape it off.
Quote from: Lumpy on April 09, 2014, 11:00:35 PM
The EHG feedback seems like humbuckers and loud tube amps, it's warm and howly. I'm looking for screechy single coils, more shrill and trebly.
Hey, where'd your post go? ???
I realized I wasn't gonna offer you anything useful. I usually filter myself before submitting, but occasionally one gets by me.
Quote from: Danny G on April 10, 2014, 12:47:37 PM
So on my SVT-II this solder trace from an electro cap burned thru. It connects to about 6 other things.
Can I solder a wire jumper to just one of the other traces to re-establish the connection, or do I need to do leads to all the parts?
(http://img.tapatalk.com/d/14/04/11/yzudebu8.jpg)
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Just one connection as the rest are all still connected together.
Lumpy a Super Hard On clone will help with the feedback.
Really, anything that will boost gain will give more feedback...
Good deal. I can shore up that bum solder joint this afternoon.
However tracking down the value and location on schem of the burned out resistor is proving to be a problem, at least trying to Google search using my iPhone.
More like eyeStrain.
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Lumpy, I suggest EMG active pickups. They're so damn hot and high end biased, that I've always thought of them as useless and couldn't fathom why Kerry King would endorse them.
Did you try messing with the coil split configuration on the humbucker? Series counter, vs series same direction winding (completely negating and buck of hum)? Hell even parallel together or parallel counter wound? That all sounds like really fun stuff to try and see what happens. Can't hurt anything. If nothing else you'll be able to hear what all of those different configurations sound like - for science.
Try installing it upside down( which would look really funny) , or turned 180 Peter green style too. The magnetic field still exists on the bottom of the pickup. It should make sound anyways.
Pissy the guitar has a strat-style 5 way pickup selector. Mongo probably not smart enough to know how to rewire his guitar. I might bring my cheap hollowbody to the space (Oscar Schmidt!), and bring the cheap Washburn home and open her up.
Danny if a Super Hardon would work, then I will give my MXR Micro Amp a try. Supposed to have 50db of gain, something like that. I will throw some other gain pedals in there and screw around with pedal order. The Rat clone was getting a little muddy though.
I do suspect a pickup replacement would be good. So I want high output pickups? Because the crummy vintage pickups which scream seem to be low output (if resistance is the same as output). I see GFS has three different lipstick pickups, roughly 4/6/8 ohms (?) or is it measured another way. 8 for the bridge, 6 for neck, 4 for middle. Maybe I should get a couple of those to replace my cheap single coils, and a P90 for the bridge?
FML
The SVT-II is still fucked.
I'm done with it. You want to be an 85 pound door stop? Go right the fuck ahead. I'm done with you.
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Ship to me. I wouldn't let it sit if I were you. How did you manage to kill it Big poppa?
It has an inherent design flaw that causes some of them to crackle, like a scratchy volume pot, but its none of the pots.
Took it to best SVT tech in Austin and he was stumped.
Someone on this forum was talking about them and mentioned a friend pulled his apart and apparently solved the problem.
Got mine out of storage, pulled it apart and immediately noticed a burned solder trace from an electro cap and a fried resistor at other end of the board.
Tracked down schematic, thought I found value of resistor. Replaced it and re-established the connection of the burned trace.
Fired it up to bias. It crackled a little as per problem immediately but that stopped once I got the voltage where it should be.
Made noise for a lil bit and sounded fine. But noticed bias voltage slowly climbing despite turning it down repeatedly.
Crackled some more. Then stopped making noise altogether unless dimed. And even that sounded quiet and thru a shitty cable.
Bias still climbing, started to smell funny but no smoke.
Shut it down for good.
Seeing if I can sell as is. I don't have the money to fix it, but was a great amp when it worked.
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Let me ask my guy, ill see if I can give you a couple extra paths to follow.
I may have gotten that resistor value wrong and just fried a bunch of other shit on it...
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Oh boy, get to tracing the circuit.
If i had the money to take it off your hands, i would :-\
150$ + buying 6550s + shipping would be too much of an investment for me, not because i want to sell it, but because im broke. Haha.
That's the thing. I'm self taught and know what I'm looking at on a schematic, but translating the schematic into the parts layout is a connection my brain has yet to make.
I was going more by the evidence that I had in identifying the resistor (1/2 watt by size, first band is black, rest burnt to a crisp) than by what's in what part of the circuit.
The only likely candidate I could identify on the chicken scratch/hieroglyphics/schematic was a 1/2w 10 ohm resistor.
Took my chances. I may have chosen correctly. But I don't know cause the amp's fucked regardless...
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I usually pick all the parts around it, then discern the value. Don't give up on it yet, it may be really easy.
I get confused because the parts next to it on the board aren't necessarily anywhere near it on the schem.
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Hmmm... Follow traces, son!
Rip that shit out and build an amp on turrets in the chassis with the iron.
Quote from: SunnO))) on April 16, 2014, 08:49:51 PM
Hmmm... Follow traces, son!
o_O How did you know I'm on acid right now?
Heh (I'm not... Sigh)
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That, and there are traces on both sides of the board. It's like this thing was built by Ford
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You can do it, papi. I promise. Just sit and stare at it for a bit.
That's what she said.
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From the Dual Showman manual
(http://i71.photobucket.com/albums/i137/mazeofliquidsmoke/ScreenShot2014-04-17at60610PM_zpsf6b728a3.png)
"an additional 8 ohm speaker can be connected to the EXT. SERIES jack for a total load of 16 ohms, set the IMP. SEL. switch accordingly"
Pretty damn cool. Was this just a Fender gimmick or does it actually work and not fry anything? I don't think I've ever owned a head that could power 3 cabs in such a way. Assuming you had the right ohm cabs, 16/16/8 for 16 or 8/8/4 for 8, would this setup send equal juice to each speaker assuming you were using identical speakers in all of the cabs? I'm thinking about getting another 2x12 for more volume because it would be a lot cheaper than starting over.
edit: this was me being hopeful. Why would the amp split the signal equally 3 ways with 3 cabs? That's not how they work. It would be a 2 way series split of course.
So.... Tube Biasing question: I have a Green Amp from 2005/06 era. I've always taken excellent care of it, and regularly re-tubed when needed. I was playing a show last week when my guitar dropped out altogether. At first glance, the power indicator light was not on, I got no sound at all, and the tubes were still glowing like normal. Nothing looked off with the tubes. After checking the fuses, we discovered that the HT fuse (1.25A/250V fast blo 5x20) was blown, and the power fuse (6.3A/250V Slo-Blo) was not blown, but looked a little cooked in the center.
Aside from the fuses being quite the task to find (and I ordered a 5 pack of each fuse), it was suggested to me that I should replace the power tubes just in case. A failing power tube can be a cause of a blown HT fuse apparently...
So, a couple of questions...
1) Is a power tube issue most likely the main reason that I could have blown the HT Fuse, or could old age and not having a standby switch be a possibility? What else could it be?
2) If I'm gonna retube (EL34's by the way), my tech showed me how to do it pretty much for the biasing. Each tube has its own trim pot to adjust the bias. I'm pretty sure that he and Joel @ Electric Amp recommended between "032 and 035"??? Not sure what that means, but IO guess I'm supposed to put one of the leads of a DMM to a green resistor at any othe tubes, and the other lead grounded on the chassis somewhere...
(http://i608.photobucket.com/albums/tt166/audioguy11295/2014-04-271146502.jpg)
I have a call in to my tech, but I believe he is away for a bit. I'm gonna do this myself, unless I figure out the tubes and fuses don't fix the problem.
What should I be setting the DMM to? mA? Any advice?
My advice is; if you are asking these kind of questions then you should have a tech do this. No shit, you can kill yourself with the voltages in your amp. No exaggeration. Also have your tech check your speaker cab for a blown speaker.
I wouldn't put much stock in Joel's opinion—he's an insurance salesman. Ask John McNeece.
Green one looks like the one to measure across. Might be connected up to test points for bias. Read the code, check its 1ohm. Chances are HT fuse going is one dud power valve, and with individual bias, you only need to replace the dud one. Replacing whole sets of output valves is to give free valves to your tech.
Update: Got the fuses, as well as new power tubes and even preamp tubes. Why not? Anyway... installed fuses and tubes. I got 3 of the tubes biased all nice and happy, but one was not being cooperative. Didn't have the range of adjustment that the other 3 did. Also, it was glowing a bit too much compared to the rest. Super hot spot! I switched the tubes around, but figured what the result would be. Same shit. So one tube position is funky. Meanwhile... that plastic burning smell that was present when I blew the fuse came back. I sniffed around the amp, and unfortunately it seemed to be coming from the output transformer. Shit!
And so... it's going to the tech on Wednesday. Time to replace shit and tune it up. It's from 2006, and although it hasn't been on the road for that amount of time, it's gotten its fair share of use and abuse. I gotta say... Joel called it back in '06 about the output transformer and all the other shit. Damn! After this, it better be all set. Until then, gonna run the V4 and see if I can blow that one up.
does anyone see any reason that the power tubes can't be pulled if an amp is going to be used for just its pre and effects out? it looks like the output xformer is out of the circuit,but double checking doesn't hurt[the amp so much] heh.
no danger. do it.
can I safely plug a bass with a distortion pedal into one input on my bass head [peavey mark 6] and a synth into the other input and run them together through an ampeg 410..
Yeah, just be mindful of how low the synth goes.
Verellen gets some hometown press:
http://seattletimes.com/html/entertainment/2023871080_madeinseattle01xml.html
Will be pulling apart my SVT in the next day or two.
Has developed a hum. Finally checked the bias last night before using it and bias way off, 32 instead of 72 k1 to ground. Got it where it should be but hum still there.
Hopefully it's a preamp tube going. But I know the power tubes are 3 years old and I've used the hell out of them.
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Question: I was using my 100 watt toobz bass amp, and trying to get all the volume possible from it. Somewhere between 9:00 and 10:00, the amp doesn't get any louder after that, or so it seems (only gets more distorted... which I'm told is normal). But when I was testing the limits in the zone there (and doing some EQ tweaking) I started to get a faint but noticeable chorus or phasey sound in the higher frequencies. Is that normal? This was during a show. Trying to make a pony seem like a Clydesdale or whatever metaphor. What happened?
This may not be the correct answer, but with my Mesa guitar amp, a lot of harmonic overtones appear as I increase the volume into power tube distortion territory. The compression effect also continues to increase as the volume goes up, so it could also have to do with that. Then there's speaker distortion, which can make some really weird sounds...
Microphonic toobz do strange things like this. Can you do a pull, swap test with some other tubes? Perhaps try and single one out?
I play a 120 watt tube head with bass and stay right there at the cusp as well. I use a vol pedal get into saturation territory, so live I'll run it at 1:00 while at practice it'll be about 11:00.
I use my 800 for bass. Not much for clean tones but microphonic preamp tubes have done similar to me in the past
I just popped in a new quad of 6L6s in my amp and one glows noticeably blue, whereas the others do not. Anyone know what the issue might be?
Funk tube, swap it to a different socket and see if it follows.
I will once it cool off a bit. In the meantime, I stumbled onto this and don't feel quite so anxious...
http://www.thetubestore.com/Blue-Glow (http://www.thetubestore.com/Blue-Glow)
Quote from: RacerX on July 16, 2014, 05:58:33 PM
This may not be the correct answer, but with my Mesa guitar amp, a lot of harmonic overtones appear as I increase the volume into power tube distortion territory. The compression effect also continues to increase as the volume goes up, so it could also have to do with that. Then there's speaker distortion, which can make some really weird sounds...
Seems like my experience. No problems while working hard, it was only until going past "useful volume" and the overtones could be described as "swirly" harmonics. I don't think it was speaker related, although half of my speakers are 70s vintage (Ampeg 8x10).
BTW, I was next to the amp, the audience might not have noticed it at all, I dunno.
If it was noticeable I'm sure at least one person looked at your pedals to see what you were using to get that sound \m/,
Sent from a can on some string using Tapatalk
Quote from: Jake on July 16, 2014, 09:36:57 PM
I will once it cool off a bit. In the meantime, I stumbled onto this and don't feel quite so anxious...
http://www.thetubestore.com/Blue-Glow (http://www.thetubestore.com/Blue-Glow)
Thanks for that link.
Question for those who know more than me:
Could one run a Sunn Concert Slave with just a fuzz pedal (as the "preamp")? And if so, how much would it sound like shit? Or not?
I would bank on that combo...personally. I have had two sunn concert leads and there is sumptin about them. I still have one of them and will die before I part ways with 'er.
Quote from: Jake on July 17, 2014, 05:15:32 PM
Question for those who know more than me:
Could one run a Sunn Concert Slave with just a fuzz pedal (as the "preamp")? And if so, how much would it sound like shit? Or not?
Probably if it had enough volume boost. I once ran a car stereo amp and cabinet with a little booster pedal I made...sounded pretty heavy!
In order to straighten out the neck of my Squier, I had to tighten the truss rod basically all the way. Now what? The neck is back on the body and it could stand to be even straighter (a little). What does this mean for the long term, etc? Can the neck be saved, etc?
You can loosen the TR, completely, and clamp it to something very flat, in the sun for a bit. I let mine sit for about a month.
Whoa. Okay, that's good news I guess (it can be fixed). But time consuming.
Have you tried putting a shim in the neck? It's super easy, and you can adjust the neck either way, depending on where you place the shim.
Plus, you only need a business card or something of about the same thickness.
I think Jakey had to shim the neck on my Squier Jag.
What about adding a washer?
http://www.stewmac.com/How-To/Online_Resources/Truss_Rods/A_sign_of_truss_rod_trouble_and_an_easy_solution_.html
Just had my SVT serviced for a retube, but also (finally) needed filter caps and apparently had a grounding issue and some other weird out-of-the-factory things.
About $500 worth of work altogether including the tubes which I ordered myself to save money.
Ouch. However, it's sounds amazing, other than the exhaust fan runs quiet as a mouse, and I shouldn't have to worry about the filter caps again until I, and the amp, are 80.
Quote from: Danny G on August 22, 2014, 03:27:25 PM
Just had my SVT serviced for a retube, but also (finally) needed filter caps and apparently had a grounding issue and some other weird out-of-the-factory things.
About $500 worth of work altogether including the tubes which I ordered myself to save money.
Ouch. However, it's sounds amazing, other than the exhaust fan runs quiet as a mouse, and I shouldn't have to worry about the filter caps again until I, and the amp, are 80.
This is that SVT II rackmountable deal that you've had (and gave you fits) for some years now? The one that a buddy told you his had the same noisy problem?
It's finally in good working order?
No this is the mid 70s SVT.
The SVT-II promptly and completely crapped out when I put it back together. Which leads me to suspect I just made the problem much worse... :\
Quote from: Jake on August 21, 2014, 02:10:57 PM
Have you tried putting a shim in the neck? It's super easy, and you can adjust the neck either way, depending on where you place the shim.
Plus, you only need a business card or something of about the same thickness.
There's a shim already - a piece of sandpaper folded up in there (covers about a half-inch area, towards the butt end of the pocket, and it's doubled up).
The stock bridge that came with it was heavily shimmed, and the neck was bowed (and it still had fret buzz). I'll play this one a bit as-is (it's not great but playable now, with a replacement Mustang bridge), and I'll get this to a tech eventually. It needs a pro setup. Too many variables for me to do a good job.
http://www.warpedneck.com/
I called this place once and considered using them for my basket case G&L neck. I think that it's like $75 plus shipping, and you can do it with only sending the neck to them.
Of course, they want you to send you're whole guitar to them and have them set the whole thing up which costs more, but you don't have to. I still may do it.
serious question..aside from demonic possession, I need an answer to my issue.
so here goes. I am experiencing an unusual static-y hum from my bass only when volume knob is turned to the 'on' position. if I touch the strings or any metal on the bass [bridge, volume/tone knob, tuners] it pretty much goes away. I haven't changed anything in my set up and this is a new problem.
im thinking its a ground issue but it gets weird.. bare with me.
I run a stock fender jazz bass with the only mod being both pickups wired together with one tone and one volume..like a p-bass. been like this for years with no issues. I run it through an ampeg rocket bass amp at practice. plug strait in..no fx boxes whatsoever. also next to that is a peavey kb-300 keyboard amp that I use for vocals. I plug a sm-58 strait in. both amps are plugged into the same power strip.
'weird thing'.. as I was fucking around trying to figure out the source of the hum, by changing instrument cables [didn't work], at one point I plugged the bass into the peavey. still had the hum. I turned the peavey off, shut the mike off, had the ampeg on and my bass plugged into it, when I went to plug the mike cable back into the peavey, I could hear 'crackling' coming out of the bass amp as I touched the mike jack to the metal input on the peavey. how is that even possible?? remember..the mike and pa were both off. the only common denominator was them both plugged into the same power strip.
wtf is going on..help please..
Try a different power strip?
I did. didn't make a diff.
I can safely say its not my bass as I tried it at home on a different amp. no issues..
capacitive energy storage discharging maybe?
long shot: verify polarity of everything plugged in to that strip. some devices are not polarized but the COMMON wire on any power cord has a distinguishing mark like a stripe or a textured line or something. if you were facing a wall socket with ground down, the neutral/common would go into the left prong. if anything is 2 wire, check that that is properly plugged in
you for sure have a loop in the mix whether or not there is more going on. the question is whether it is a common loop or a ground loop. you will get tickled from a common loop like if you touch the back of your wrist to the edge of something metal and you get a 20-30v tickle. also a seriously floating ground can give you a tickle. a potential actually exists across physical material of the earth ground and if you pipe the ground from a remote location via low resistance wiring an then ground on location, there can be a potential difference(ac voltage) which then flows current and makes noise. 60 cycle hum is no coincidence. that is the power grid in your shit.
fwiw, a person is a big capacitor+resistor and we certainly affect the circuit we are plugged in to. we are good noise filters when we attach our bad RC filter selves to a feisty circuit and are excellent rabbit ears accessories for pulling in that really weak squirrely station. tv tuner is a variable capacitor amongst other stuff.
does that mean I could be in danger of being electrocuted?? I haven't felt any tickles for what its worth..
also why all the sudden?? same set up and it wasn't happening before..
Quote from: mortlock on September 07, 2014, 10:56:08 PM
does that mean I could be in danger of being electrocuted??
Absolutely.
You gotta drive a spike into the dirt to ground that sucker.
if I get out of the same power strip and go to another outlet, will that fix it??
if you still have any direct wired death amps yes because the hot wire is now attached to like the transformer frame and if you touch that frame and ground = ZAPPO.
if you actually still have one(I did my kustom 30w combo and have to do an old bose mixer yet)take a cut off computer cord and rewire the amp. just attach the ground and the common to where only the common once was. this always ties the common to ground and doesn't permit a common loop from a floating common-ground potential.
modern 2 wire stuff like wall warts is 2 wire because it is transformer isolated. that means that the transformer frame floats or is sealed away from any contact, then only the 2 wires from the secondary coil, which is electrically isolated from the rest go out. this then is like a battery since the energy has been inducted through the transformer core, not directly wired.
still try to plug those in correctly because ripple is out of phase still. out of phase flows current and makes 60 cycle hum.
same setup, wasn't happening before: something changed. maybe subtle like plugged in wrong or maybe something failed somewhere. have to look around and meditate heh. GL
edit: my kustom combo has a 2 position power switch that reverses the polarity of the input or internal power, w/e to get rid of hum, just thought of that. so polarity fubars did/do exist
I serious apreesh the words of wisdom..thanks.
I'm assuming you have the reissue Rocket. Unless you have an old-school, '60s vintage Rocket, chances are good that it has a 3 pronged, grounded power cord. If you ARE using an oldie, jibberish's wisdom jibberish could possibly apply.
just more musings on that noise:
I wonder if the power switch only cuts the hot wire out?
maybe power supply filter caps bleed out via the ground or common when the mic jack momentarily shorted or completed some path as it was plugged in.
you also could have created RFI which picked up in the pickups or bass amp circuit
edit: dunwich may have some insight since he lives inside of amps. there may be common things that happen at certain times that he is aware of or w/e
Quote from: mortlock on September 07, 2014, 08:23:41 PM
serious question..aside from demonic possession, I need an answer to my issue.
so here goes. I am experiencing an unusual static-y hum from my bass only when volume knob is turned to the 'on' position. if I touch the strings or any metal on the bass [bridge, volume/tone knob, tuners] it pretty much goes away. I haven't changed anything in my set up and this is a new problem.
im thinking its a ground issue but it gets weird.. bare with me.
I run a stock fender jazz bass with the only mod being both pickups wired together with one tone and one volume..like a p-bass. been like this for years with no issues. I run it through an ampeg rocket bass amp at practice. plug strait in..no fx boxes whatsoever. also next to that is a peavey kb-300 keyboard amp that I use for vocals. I plug a sm-58 strait in. both amps are plugged into the same power strip.
'weird thing'.. as I was fucking around trying to figure out the source of the hum, by changing instrument cables [didn't work], at one point I plugged the bass into the peavey. still had the hum. I turned the peavey off, shut the mike off, had the ampeg on and my bass plugged into it, when I went to plug the mike cable back into the peavey, I could hear 'crackling' coming out of the bass amp as I touched the mike jack to the metal input on the peavey. how is that even possible?? remember..the mike and pa were both off. the only common denominator was them both plugged into the same power strip.
wtf is going on..help please..
grounding issue, your body is acting as a better ground for the hum then the actual ground connection is
I have an SMF head that blew a power transformer about 6 months ago. The tech took it out and sent it to Mercury Magnetics and they cloned it. It worked fine for the next 6 months and then blew the power transformer again. It was sent back to mercury and they said it was a "slow burn" and not really their fault but replaced it under warranty anyway.
When the replacement was installed the tech told me that the secondary on the pt was regularly getting 1 amp of current and was rated at about 500ma, it was probably going to burn out again in about another 6 months. There are no faults or problems in the circuit, everything matches the schematic. They are talking about adding a big resistor before the secondary to knock the current down to a safe level, does anybody have any experience with this?
What I would like to know is is this a problem inherent to this model? They weren't made for very long, could this be why? Any other insight into this problem would be appreciated.
Not technically an Amp Tech question, but some pretty smart fellas in this thread might be able to offer their opinion on something my caveman brain cooked up.
I've been thinking about introducing some 15" speakers into my guitar setup since dropping down to an A tuning. Can someone tell me why a speaker cab with this configuration of 12s and 15s would be a bad (or not so terrible) idea? I'm not trying to get maximum driver/bass efficiency or super massive bass tones that will cross into a bassist's spectrum, but I do like the idea of really moving some air. Thoughts?
(http://i84.photobucket.com/albums/k32/jakeh_02/215-212_zps107b9c89.jpg)
Ha, I had a dream last night about designing a speaker cab with two 12's and TEN 8's. No knowledge about speaker design, so have no idea how it would sound, just seemed cool in the dream.
Mixing speakers is unpredictable because they won't operate in the same phase across the frequency spectrum. Means random mid peaks and cancellations. Plus the sound varies in more complicated ways around the room, instead of just being treble beamy.
Quote from: beerrhino on September 19, 2014, 04:33:51 PM
I have an SMF head that blew a power transformer about 6 months ago. The tech took it out and sent it to Mercury Magnetics and they cloned it. It worked fine for the next 6 months and then blew the power transformer again. It was sent back to mercury and they said it was a "slow burn" and not really their fault but replaced it under warranty anyway.
When the replacement was installed the tech told me that the secondary on the pt was regularly getting 1 amp of current and was rated at about 500ma, it was probably going to burn out again in about another 6 months. There are no faults or problems in the circuit, everything matches the schematic. They are talking about adding a big resistor before the secondary to knock the current down to a safe level, does anybody have any experience with this?
What I would like to know is is this a problem inherent to this model? They weren't made for very long, could this be why? Any other insight into this problem would be appreciated.
PT secondary as in : the main power supply for all the tubes secondary?
if so, this is telling you that the entire amp circuit needs an amp of juice to function.
the only way to kill current with a resistor is to series and increase the overall resistance to limit current. the only problem is that you also eat half your voltage in the resistor drop. this is dissipated as pure heat. so doing some math...what is the secondary voltage? 400V..(round number) so your amp needs 400 watts to run (I*V=W=power) doesn't seem too unreasonable, esp if the secondary is really even less like w/e 300v.
anyway, you are going to have to drop 200 volts at .5 amp in that resistor = 100watt dissipation
also, what is going to happen to your amp circuit with only half power and current limiting?
can you get a 1 amp rated PT? that is the cheap(er) one isn't it vs the output one?
I don't know about cheaper, jibberish, the first one was more than $500 w/labor. I just don't understand why the amp came with a transformer that can only handle 500ma if the circuit draws 1amp
Sounds like they established that the first transformer was wrong for the amp. Then replaced it with same.
^
Actually, yeah.
Sounds like beerrhino'll need a burlier tranny next time round.
The first transformer was the original transformer from the factory. I sounds like it was originally built with the incorrect transformer.
Quote from: beerrhino on September 25, 2014, 07:56:02 PM
The first transformer was the original transformer from the factory. I sounds like it was originally built with the incorrect transformer.
can your [cough] techs get the original test points from the mfr of your amp?
by test points I mean a diagram with places to put the DMM leads throughout the circuit and a list of values you should be reading.
what I am getting at is, what if certain other electrical parameters have changed over time to be pulling too much juice vs original.
I can't see amp mfrs making sketchy products like that that would need constant service
if you beef up the power supply, later you might find something else that finished failing and when fixed only draws <500mA now
just something to consider in the back of your mind. I don't think we have the whole story yet
Quote from: beerrhino on September 25, 2014, 07:56:02 PM
The first transformer was the original transformer from the factory. I sounds like it was originally built with the incorrect transformer.
That's what Foxen & I are getting at. And if they knew it was the wrong tranny
before replacing it with a clone of the same, I'd call it at least partly their fault, too.
I have one more question about that SMF head.
at this point in time, we know that the state of the circuit is such that it has a 6 month field life between service. if you use it again as is, it looks like it will be back in 6 months again.
here is the key question: how old is this amp?
IF it was defective initial design, then I have to assume this amp is about 1 year old. 6mos from factory new=1st tranny meltdown, 6mos later=#2 meltdown.
you would be best served by upgrading the power tranny to 1 amp model.
If the amp is several, or quite a few years old, then logic dictates, that for all those years, a 500mA supply was fine. the 500mA tranny is NOT THE PROBLEM. something changed and your less than impressive techs need to find it.
Sound City made the SMF series somewhere around the late 70's-early 80's I believe. I've had the amp for about 7 years although it hadn't seen much use for the first 6.
The techs tell me that everything else in the circuit is running exactly as it should. I have to take them at their word, they've done excellent work for me in the past.
Quote from: beerrhino on September 28, 2014, 11:49:13 AM
Sound City made the SMF series somewhere around the late 70's-early 80's I believe. I've had the amp for about 7 years although it hadn't seen much use for the first 6.
The techs tell me that everything else in the circuit is running exactly as it should. I have to take them at their word, they've done excellent work for me in the past.
ok, good luck. hope you figure it out.
stupid question from me number 216..
I want to add another cab to my bass rig. I want a 2x15. I currently have a peavey mark vi head and an ampeg 4x10.
the cab is 200 w at 8 ohms and the head min 2 ohm load. rated at 400 w at 2 ohms and 250 w at 4 ohm. what do I need to make it work in the way of a 2x15. watts?? ohms?? please educate my dumb ass..thanks..
mortay, i'm writing you a book because I think you are worth it heh. this trickery frees you if I can explain it effectively.
Quote from: mortlock on September 28, 2014, 05:13:23 PM
stupid question from me number 216..
I want to add another cab to my bass rig. I want a 2x15. I currently have a peavey mark vi head and an ampeg 4x10.
the cab is 200 w at 8 ohms and the head min 2 ohm load. rated at 400 w at 2 ohms and 250 w at 4 ohm. what do I need to make it work in the way of a 2x15. watts?? ohms?? please educate my dumb ass..thanks..
hey chief, I want to give you a couple tools.
1)reduce the confusion factor by using a concept called a "black box". powerful analysis trick universally used. here's how it works: you literally only look at the inputs and outputs to some chunk of circuitry. an op amp is a great example of black box in action and no one even knows it. do you need to know that there are whatever 20 transistors and 50 capacitors and 100 resistors and whatever all in that little can? no. we only need to know it needs power and some input and you get some output. we black box the guts.
really any chip like a 555 timer or w/e is a black box.
ok wtf does this have to do with bass and speakers? ignore the contents of the box. just go with the black box parameters of the entire cabinet. you have one black box that is an 8 ohm load that can dissipate 200watts of power. you want to add another black box with some resistance and some power dissipation rating(this is max watts)
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2)
now ask yourself questions: how do I want my power distributed? do I want half to go to each black box?
[side story. been talking with my nephew about LED's for his super van. he is a wiz at IT shit. I bow before him, but he is pure nub at electrical theory. I showed him how to set a voltage by using a pair of resistors as a voltage divider. like how tube bias or pedal transistor bias is set with 2 resistors. it was awesome seeing the light go on and he was happy amazed how that worked and went right home and sawed a 12v signal down to 4v or w/e he needed]
electricity likes path of least resistance more, but some goes through the higher resistance too if another path is added in parallel. like one faucet on full(not much resistance to current flow)and one on a trickle(big resistance). the total water flowing is the total of both faucets, but you can see the higher resistance flows less water. feel that inverse ratio. feel that if both faucets are opened the same, they will flow the same amount of water....feel that if both black boxes have the same resistance, they will both dissipate the same amount of energy. they will split whatever the amp is dishing out fiddy-fiddy.
so , to split power in half, both resistances must be equal. if you want 1/3 and 2/3, then resistance 1 is 2/3 and resistance 2 is 1/3. see that inverse shit. a 4ohm and an 8 ohm resistor in parallel would make that ratio and send 2/3 power one way and 1/3 the other way respectively. so that's how you set the actual power distribution, by juggling how each unit resists the flow.
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number 3
power handling adds no matter how you run juice through . that black box is burning off power. if you have that 200w dissipation(ie handling) cab and a second 200w cab, total power handling is 400w. CAVEAT:make sure you distributed power correctly(see #2) so you dont put too much power through either cabinet. the 50/50 thing is safe math haha.
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number 4
what total resistance does the amp see so we know what kind of power it will be putting out.
first off, i dig stuff that is stable at 2 ohms. that is a fucking beefy amp that can flow some current and not burn up. i love it.
the lower the resistance, the more current it will flow until you get to zero, which then asks the supply to flow every last electron it has , voltage drops to zero and you have shorted out your supply. this melts the outputs. so 2 ohms stable is badass.
2 ohms is going to sound sloppier than 4 or 8 because the amp really has lost tight control over the situation, but tha could be a good thing for your tone, or a bad thing. have to play with it. here again, the 50/50 thing makes for easiest math. you have an 8 ohm cab. IF your new cab is also 8 ohms, then everything is split evenly. in a parallel hookup,the amp sees both flows so the 2 smaller 8 ohm flows become a double sized 4 ohm flow when they are combined..feel the inverse symmetry.
your amp does 250 watts max power output at 4 ohms resistance(load)
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put it all together: i want to make loud but no smoke.
we dont overpower a cab, or short out our amp. that's what we have to watch. solid state likes high resistance and hates low resistance, basically opposite of a tube amp. (open output circuit destroys tube amps = infinite resistance load. a short would cause less havoc)
so of we do the 50/50 thing just to set a relative point AND skate with EZ math. we get ourselves a second 8 ohm cab rated at 200 watts
1) i have 2 of these 8ohm, 200 watt black boxes so i go halvsies the whole way. symmetry
2)power, split in half due to equal paths
3)cab total power handling is 400 watts, split in half
4)amp sees 2 8 ohm loads in parallel for a grand total of 4 ohms
5)amp can put out 125 watts max into each cab (250 total split down the middle)
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epilog. if you had a 4 ohm and 8 ohm cab in parallel. logic that the total flow will be 4 ohms big plus even more since we are adding some smaller 8 ohm flow
fuck the math, just interpolate this: 4 and 4 would be 2ohms, but this is 4 and 8, so not as much flow as 2 ohms, but more than 8 and 8 which is 4. HEY i go with 3 heh
3 is close enough for government work. and you can estimate amp output somewhere between 2 and 4 ohms to get the sense maybe it would be doing 325 into 3 ohms..
watch this mismatched ohm thing becasue that double current throws bigger wattage down lower resistance path and you could just be mostl;y playing one cab and then cook it when you turn it up too loud. obviously a 200 w amp isnt going to brutally rape 200 watt cabs, but you could still cook it if 200+w goes to one cab and 100 to the other.
read this over a few times. once you get this feel. these issues get a lot easier to sort out quickly. and symmetry always keeps it the simplest.
i think i am going to have a rare cigarette. i earned it. go rest my ash after all that typing.
dude you rule.. thank you for taking the time to try and get this shit to sink into my head.
basically what I took from that is I want a cab that matches my ampeg and ill be in good shape splitting things 50/50. 200 watt/8 ohm 2x15. ill never understand this crap, I have tried but electricity fucks me up.
i'm glad you checked that out.
ya, if you stay 8 ohm, the power gets split even. this is about volume. keeps cabs about same volume.
you could get a cab that can take 400watts max or something. if it is 8 ohm, it still is getting 1/2 the amp's power
as you audition speakers, you might want to keep relative efficiency in mind also. especially big wattage stuff, like w/e a 1000w system. sometimes those take a lot to get going and it would be way quieter than a more efficient lower power handling one when they get the even split. idk. maybe they have very efficient hi-power bass setups. then it wouldn't matter as long as it played the same volume as the 200w 4x10
this is where the bass players can recommend shit to try. the good thing is if you stay in bounds, you can try stuff without fear of damage.
happy hunting
is there a correct way to stack cabs?? I usually see the 4x10s on top of the 15s. does it really matter??
Whichever your hernia repair prefers.
bigger (wider) goes on the bottom. smaller (lighter) goes higher up. nothing to do with sound, just physics and laziness.
this is the speaker that goes UNDER the stage.
we are not worthy.......
http://www.crutchfield.com/p_13692116/JL-Audio-13W7AE-D1-5.html?tp=111&awkw=75621282025&awat=pla&awnw=g&awcr=47439192385&awdv=c
edit: 32mm cone excursion. hello
any suggestions on a good 15" speaker for bass guitar application??
Eminence Beta and Deltas are pretty tried and true. Easy to get re-coning parts if they need it too.
How much maintenance pain am I getting into if I buy a '70s Orange OR80 or OR120?
I've heard of the Matamp versions eating tubes and generally falling apart but maybe it's just because they sound so sweet when they are cranked?
How about the Oranges?
No worry. Good amps.
JCM800 2203 Pre-Amp pot question:
Since I run my 800 loud and clean, I use the pre-amp set between 1.2 and 1.5. And there is a HUGE diff in that 0.3 range.
Can I swap the out the pot with a lower value to get a more useable sweep?
I'd like some wiggle room between LOUD and TOO FUCKING LOUD \m/,
Quote from: fallen on November 16, 2014, 03:11:13 PM
How much maintenance pain am I getting into if I buy a '70s Orange OR80 or OR120?
I've heard of the Matamp versions eating tubes and generally falling apart but maybe it's just because they sound so sweet when they are cranked?
How about the Oranges?
Love my 72 Or120 great dependable amp.
Quote from: Danny G on November 18, 2014, 04:33:57 PM
JCM800 2203 Pre-Amp pot question:
Since I run my 800 loud and clean, I use the pre-amp set between 1.2 and 1.5. And there is a HUGE diff in that 0.3 range.
Can I swap the out the pot with a lower value to get a more useable sweep?
I'd like some wiggle room between LOUD and TOO FUCKING LOUD \m/,
Try running your master lower and the pre amp higher. Is that too dirty?
I like to have the master up as close to 7 (or higher if need be) as possible to drive the E-34Ls and get the clean cutting power
Below 6 and it's just not "loud" enough. Turning up the preamp for more volume when the master isn't where it needs to be doesn't really help it cut through better
I run a 12AT7 for V3 to further pull the gain back a bit. Get all my dirt through a pedal
Try a pot with a different taper Danny. If its linear in there now, go audio or vice versa. Maybe it'll do what you're after. Maybe it'll be worse. I'd almost guarantee one or the other.
50/50 chance. My inner samurai likes those odds heh \m/,
Quote from: Danny G on November 18, 2014, 04:33:57 PM
JCM800 2203 Pre-Amp pot question:
Since I run my 800 loud and clean, I use the pre-amp set between 1.2 and 1.5. And there is a HUGE diff in that 0.3 range.
Can I swap the out the pot with a lower value to get a more useable sweep?
I'd like some wiggle room between LOUD and TOO FUCKING LOUD \m/,
I think you might just want to pull the clipping diodes, would be easy and give you a much cleaner sound.
Marshall model 2203/2204 doesn't have clipping diodes. That's the 2205/2210.
And jcm900s
I think those have an A1M pot for gain. Since the area you are concerned with is the beginning of the taper, the A should have the slowest action at the beginning of the travel..So not sure that the pot change would affect this as you wish to. Maybe changing (increase value) the cathode resistors in v1a and v1b to lower gain might get what you need. Typically dudes change (lower value) to get MORE gain but seems it would also work to lower gain.?.
Foxen?
Hey Riffer,
My Pharaoh has lost its smoothness! It's sounding gritty and sputtering, even with low gain settings. Doesn't matter where the diode switch is set either. Could it be an input transistor? Or do you have any tips what to check?
Did you rule out the power supply and patch cables by swapping them out with known good ones?
Yup, power and patch cables are tested good, also tested a couple of other fuzz pedals in the same place on the pedalboard and they sound smooth and creamy.
There's plenty of output from the Pharaoh, it's just the distortion itself that's grainy/gritty, for lack of a better word. Sounds like non-musical, odd order distortion in a sense.
Dang that sucks. Mine is still sounding brutal. Good luck. Did you crack it open to see if it's anything obvious like a solder joint? Maybe run a signal through it and poke around inside lightly.
Yeah, I better take a look inside. I really want to get it going before we start recording next month.
heh. howabout shipping it to mark to fix and bless properly? or has this one changed hands and not his responsibility anymore?
there's just something wrong with this picture where you guys are planning an exploratory to try and figure it out, when the person who makes them is here.
I would consult with mark before I did anything. email/bmail him.
if an op amp failed, what exactly are you going to do anyway? how would you even know how to test for a bad op amp? talk to mark is how.
Nothing wrong with opening it and taking a look. If it were mine and all it was was a solder joint, I'd feel kinda silly for shipping it out for something simple.
What RAGER said.
Four screws is all you need to remove to check and jiggle shit. Riffsir likes DIY types. He'd probably trouble shoot over the phone with you.
Quote from: showdown on December 27, 2014, 11:43:18 AM
Hey Riffer,
My Pharaoh has lost its smoothness! It's sounding gritty and sputtering, even with low gain settings. Doesn't matter where the diode switch is set either. Could it be an input transistor? Or do you have any tips what to check?
My initial guess is a bad solder joint on one of the associated components to the first two transistors. Taking the transistor out of bias.
Quote from: jibberish on December 28, 2014, 06:49:51 AM
heh. howabout shipping it to mark to fix and bless properly? or has this one changed hands and not his responsibility anymore?
there's just something wrong with this picture where you guys are planning an exploratory to try and figure it out, when the person who makes them is here.
I would consult with mark before I did anything. email/bmail him.
if an op amp failed, what exactly are you going to do anyway? how would you even know how to test for a bad op amp? talk to mark is how.
I will fix any of my pedals for anyone for as long as Im mentally and physically capable. Cant say how long that will be. Exclusions are blood/piss/vomit/shitting on the thing. Hank 3's LSTR went through a basement flood, was submerged for days. He dried it out, and it fired right back up. I woulda covered that if it didnt work..I won't cover user mods or improper power supplies..and shitting on it.
I am happy to fix and ship it back, or am happy to help troubleshoot. As jib says tho, If you dont know ask.
Quote from: RAGER on December 28, 2014, 09:44:09 AM
Nothing wrong with opening it and taking a look. If it were mine and all it was was a solder joint, I'd feel kinda silly for shipping it out for something simple.
Agreed, and it is indeed encouraged. Can be a very simple fix, worth a try.
Quote from: VOLVO))) on December 28, 2014, 09:54:47 AM
What RAGER said.
Four screws is all you need to remove to check and jiggle shit. Riffsir likes DIY types. He'd probably trouble shoot over the phone with you.
Exactly. As Rager says, run a signal through it, and poke around EVERY component and wire solder joint with a pencil. Any bad solder joint would likely show itself this way. If no luck, I will fix it with a new pcb.
I still wanna build one of these for myself... Just for funsies.
Even though my Pharaoh is the best Pharaoh.
Can certainly be done. I heard someone is selling DIY Pharaoh pcbs. Pretty cool.
Sell me the parts.
8)
Sell him the pcb. Make his source his own damn prats. Project!
So.. Lazy...
Just had a build idea/thought/theory:
I've been using a second TU-2 in my guitar chain as a poor man's channel switcher.
I don't need an ABY box per se, I just need to have a split signal with a kill switch on one.
Could I just make a box with two output jacks, one straight thru from the input and the other wired to the switch (with an led wired in to let me know its on)?
Or due to buffering concerns or some other something-or-other do I need to build/buy a proper ABY?
Unless you already have a work station set up and those type of parts on hand and are building shit regularly, I would just buy one cuz they cheap nowadays.
I have probably everything I would need to build the simple splitter/kill switch
Quote from: Danny G on January 14, 2015, 10:58:32 AM
Just had a build idea/thought/theory:
I've been using a second TU-2 in my guitar chain as a poor man's channel switcher.
I don't need an ABY box per se, I just need to have a split signal with a kill switch on one.
Could I just make a box with two output jacks, one straight thru from the input and the other wired to the switch (with an led wired in to let me know its on)?
Or due to buffering concerns or some other something-or-other do I need to build/buy a proper ABY?
I think a simple test would be to just hard-wire a splitter and see how that sounds with the 2 amp chains. I would guess that once the weak hi-impedance guitar signal goes through any pedal, it has now been buffered/boosted and probably would work. splitting the guitar output would maybe change the tone since it is looking into half the impedance as before, but maybe it doesn't matter either, especially if those signals are going through pedals anyway.
the pain in the ass would be installing and powering an LED heh. otherwise a stompbox switch just single pole would work for the kill. double pole would be cleaner, kill the ground too. I would probably do that, like a true bypass switch would work.
Here's what the signal chain would look like:
Wah--TU-2--Blues Driver--Phase 90--Tremelo--Splitter
Signal 1: amp 1
Signal 2: Loop Station--amp 2
The secondary TU-2 has been functioning as the splitter.
Hence having a dedicated switcher as I'm just tired of pulling it from my bass pedalboard haha
I've been using the signal split to have the loop station go into its own amp. Or when LS is not in use the second amp can act as a boost channel.
yeah, you are all active buffered. just do it. it will work.
listen for drops or changes in the amp that is always on when you kick the second one in and out. that's the only thing I could think of to watch for.
I wonder if a dead stompbox would work as the kill switch. full true bypass then full kill into the guts. then just add that after one of the splits on a stock hardwired a/b splitter
I wonder if a good stompbox, just not powered would also work
"laziness is the true mother of invention" you can quote me if you like. heh
maybe there is a way to do this without lifting a soldering iron or a screwdriver.
Quote from: jibberish on January 15, 2015, 03:12:26 AM
"laziness is the true mother of invention" you can quote me if you like. heh
Just did \m/,
Well in that case I've got a couple noise generators around (pedals with bad components). I'll just run them through my beatstep and a Sherman filter bank for light weight live rig.
Quote from: jibberish on January 15, 2015, 03:12:26 AM
maybe there is a way to do this without lifting a soldering iron or a screwdriver.
I could just find a used TU-2 on the cheap, heh
Am thinking of running this part if the chain on a separate board, I only need the loop station for OoS.
Plus I added one of my lady's Boss foot switches to the Loop Station to better control it. So that's three extra pedals right there.
Looking forward to remedying this situation
#gear #fun #imissbuildingshit
a video is worth 1k words
introducing the $200 killswitch
How about a Vol pedal just down stream of the tuner's "always on" signal? roll it on as needed.
I need an on/off stomp switch.
I have all the parts to build the splitter box. But also a friend has a ABY box he ain't using and says he'll give me.
See what happens first
Friend just gave me said ABY box and wired it, loop station and the loop foot switch onto an auxiliary pedalboard.
Didn't have to fire up a soldering iron!
But I did have to cut some pieces of green electrical tape to cover the SUPER FUCKING BRIGHT GODDAM BLUE LEDs, tones them down so I don't need a welder's mask to look directly at the fucking thing.
Fuck super-bright LEDs
I impulsively bought a used Squier Jaguar on Ebay a few months ago, because I wanted to try a Jaguar and I got a good deal (170 shipped, new they are 299). It was from a pawn shop, so my expectations on quality assurance were dialed back.
Turns out the neck is bowed (I have the truss rod maxed out, and it still has too much relief). The original bridge was a disaster, so I got a Mustang bridge replacement, which needs to be set up, and now I see the worm gears (I think that's what they're called - the threaded bits) are starting to vibrate loose and walk themselves out. They'll need lock-tite, once the bridge is set up 'perfectly'. The choke switch seems to be broken (kill switch on the pickups - I was admittedly riding it pretty hard, which sounds cool). I can imagine that fixing the wiring could be a real pain.
So that's three issues which I can't address on my own... Is this thing a money pit that I should give up on? Worst problem is the bowed neck, I know they can be fixed but it seems like the guitar is "totaled" (in the car insurance sense of the word - it needs repairs which may exceed the value of the guitar).
The really dumb part is that I have two really nice Fenders already (80's Strat and recent MIM Esquire) which I love. I don't even need this guitar, and I don't need any projects. I have other things to worry about. It does seem like a cool guitar, if everything was working and set up properly. This one might be cursed though.
Please advise.
Take the neck off, loosen the truss rod completely, and get some cheap clamps, and bow it he opposite direction, and forget about it for a couple weeks. Bet it was finished as green wood (not totally dry.)
Its an easy fix if you don't actively need the guitar.
The switch is just a part swap. No big. Take a picture of current wiring, remove switch, replace.
Piece of shit sloppy chinese cast parts, blue loctite, if you're worried about stripping out the allen heads after loctite, use beeswax instead. Heat it till it melts, then put a drop on either side of the thing. Lots of old school tricks to do.
That sounds good, thanks!
What kind of clamps should I use? I do have a good table I can clamp that fucker onto. I think I'm supposed to back the truss rod out like halfway (let it bow out) and then clamp?
Just fixed my Small Clone for no other reason it was broken.
Seems a wire broke off from the switch. Fixed it, now it works.
Still don't have much use for it tho. But hey, it works.
Maybe give it a try on the lowest speed setting and dial in the depth to taste—that's the only way I've ever been able to stand chorus pedals.
I used to use chorus a lot until the last 1/3 of my time in Southern Gun Culture. Just kind if outgrew it.
Fixed it to see if I'd like to bring it back, toyed around for a few minutes and thought "meh"
Actually wound up using the Small Clone for a guitar track on my latest RPM Challenge album. Sounded cool but won't be making its way back to my pedalboard tho.
In other project news, I need to completely rewire my Les Paul Studio and Paul Stanley Iceman.
After years of fucking with them, both have developed grounding issues.
Beefed up the power filtering in my NYC Big Muff, it's dead quite now. A lot of sites were saying muffs are just noisy but I think you just need the right filtering if you are hooked up to a powersupply.
Hey Spook, did you do the R-28 mod to your Phase 90? I fried one trying to add a blinking rate LED to the pot. I've since found out that it gets attached to one of the legs on the IC and grounds out at a resistor. Anyway, I've pulled the legs up on every single resister on the broken 90. I'll have to get Drag Pack Keith to take better pics, my laptop's cam must've been old stock from a Motorola Razor phone.
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150603_095105_zps0yvi4u1n.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150603_095105_zps0yvi4u1n.jpg.html)
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150603_095037_zpsi6sngusz.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150603_095037_zpsi6sngusz.jpg.html)
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150603_095024_zpsgyywjobi.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150603_095024_zpsgyywjobi.jpg.html)
Also, folding TV dinner tables make great pedal-boards.
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150531_182635_zpsfqnovufa.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150531_182635_zpsfqnovufa.jpg.html)
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150531_182228_zps7uy0bpea.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150531_182228_zps7uy0bpea.jpg.html)
I recall a time when none of y'all would touch electronics on the old board. Seeing all of this activity is really cool.
To progress!!
I've managed to bugger 1-Phase 90, 1-Phase 90 clone (GGG), 2-MXR 108 FF's, a black Russian Small Stone, and a Screaming Tree. But I just need a new transistor for the Tree, and I might send it to Ronsound down in Indiana. I've done some pretty good Mem Man stuff, Muff's, and VOX/Crybabies.
Just got my Ampeg 410HLF back from a friend who used it for a bit and then stored it away - and there's some unpleasant buzzing from the bottom left speaker.
Before anyone asks, I didn't have time to open it up and poke around after getting it back and before coming into work, just turned it on and played for about 5 minutes before work.
I'm not really sure what it is, because it's not the sound I had in a speaker that had blown in it long ago and had replaced. It's a buzzy vibrating sound that's only present while playing, and is especially prominent during low notes (anything on my low B really bring it out). I know buzzing from a speaker can mean a grounding problem. The sound - please bear with me and try to picture this - is like if I were to have laid the cab on its back and set a guitar pick on the cone, and then started playing. It doesn't sound like something where the speaker isn't screwed in properly or like there's something rattling around inside the cab because of the ports.
Should I just get a new speaker? I was hoping to use it next week for a project and I don't think I have the time to send it out for a 2 week repair turnaround. The cost is irrelevant, it's a time thing.
You need a tech to replace a speaker?
Well of course not, I'm just wondering if anyone can diagnose that as anything other than "just replace your speaker."
Of course I can replace the speaker myself, I just don't know if it's as simple as it seems. I haven't had any issues with cabs in a few years and I don't know if it's as straightforward as that.
The paper dome might be pulling away from the cone. This happened to me. I couldn't see it when the speaker was still in the cab, and assumed the worst. When I pulled the speaker to replace it, I eyeballed it from a horizontal position, and could see the dome was pulling up a tiny bit. This would be less likely with newer speakers, and more likely with older units where the glues (?) are drying out, the cabinets have been played a lot, etc. Remove the speaker and look at it. There might be other tears or damage to the cone that you can't see until you remove it from the cabinet (which are also repairable). Once you have it out,get some light on it and test the edges of the dome where they attach to the cone (carefully, duh) with the tip of an exacto knife/other fine-tipped implement. If you find a spot where it's pulling up, you can repair it yourself with rubber cement (I believe) or maybe diluted Elmer's glue (I forget what I used, this was like 7 years ago). Tissue paper and glue are sometimes recommended as a patch. Google speaker repair, glue, paper dome, etc. There's info about this on the web. I remember applying glue to the underside with a small artist's brush, and also doing a light skim coat on top to help seal it. (Just on the limited 'fix' area). Exacto knife was prying up the dome edge while I applied glue with my other hand.
Since your buzzing really stands out when playing low notes (the most active vibrations) and not buzzing all the time, it makes me think your speaker is repairable. If it is the dome pulling up, or a small tear in the cone, it's super easy to fix yourself. Even if you're totally not handy, it's still worth trying before you spend 60 bucks (or whatever) on a new speaker.
Thanks, Lumpy. That's pretty much exactly the kind of feedback I was hoping someone would respond with.
Unfortunately, I couldn't find any blemishes anywhere on the speaker after pulling it out, and all the glue seems to be intact. I think it'd be smarter and more cost-effective for me to replace the speaker than to take it somewhere and pay a bench fee just to have them tell me I need a new speaker after poking around very carefully last night.
I didn't make it clear... You have to actually test the edges of the dome. Use a small blade and carefully see if the dome is loose anywhere (ever so lightly, pick at the edges). It might not be visible (maybe it's laying perfectly flat) but once the speaker is jumping, you can hear it. Is it an older speaker? An older speaker is more likely to have this issue.
(It could also be something else, I have no idea.)
do you have a signal generator? There's apps for signal generators you can get for tablets and phones. They do cost money though.
If you do, find the brown note and feed it into the amp, then you can pinpoint exactly where that noise is coming from. You have materials vibrating against one another in some way shape or form. paper of the cone ripped, surround to the speaker frame, dust dome to the cone, frame to the cabinet, cabinet pieces vibrating together, and finally grills and/or grill cloth. something. make it do it and resonate so you can find it. If you don't want to spend money of a signal generator, find a friend to play that B note indefinitely until you can find it. Fixing it after that point you can probably figure out. modeling glue works pretty good for repairing cones. Wood glue for the wooden stuff, and I normally ham-fist grills to cabinets with screws.
There are online frequency generators - here's one :
http://onlinetonegenerator.com/subwoofer.html (http://onlinetonegenerator.com/subwoofer.html)
(download the "additional test tones" and play them on your phone through your amp).
You could also just have your buddy play problem notes on the bass while you look/listen.
Actually did all of what both of you suggested and found a small separation in the glue along the outer rim, glue is setting now.
Tone generator helped me find it. Thanks y'all!
Did it stop buzzing/farting/whatever sound it was making?
Sure didn't. Just replaced the damn thing and called it a day.
God dammit.
Well save the speaker, maybe it can be fixed later and you keep it around as a backup.
Yeahp, not a huge deal. It shall sit in the closet until a stormy day calls it out to be repurposed. Thanks for being helpful though, I seriously appreciate that.
Ive not moded my phase 90 yet been pretty happy with it as is so far.... Im going to look into though.... I dig your pedal board that is a nice looking piece of wood.
Quote from: Baltar on June 03, 2015, 09:45:20 AM
Hey Spook, did you do the R-28 mod to your Phase 90? I fried one trying to add a blinking rate LED to the pot. I've since found out that it gets attached to one of the legs on the IC and grounds out at a resistor. Anyway, I've pulled the legs up on every single resister on the broken 90. I'll have to get Drag Pack Keith to take better pics, my laptop's cam must've been old stock from a Motorola Razor phone.
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150603_095105_zps0yvi4u1n.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150603_095105_zps0yvi4u1n.jpg.html)
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150603_095037_zpsi6sngusz.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150603_095037_zpsi6sngusz.jpg.html)
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150603_095024_zpsgyywjobi.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150603_095024_zpsgyywjobi.jpg.html)
Also, folding TV dinner tables make great pedal-boards.
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150531_182635_zpsfqnovufa.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150531_182635_zpsfqnovufa.jpg.html)
(http://i8.photobucket.com/albums/a47/bren1973/WIN_20150531_182228_zps7uy0bpea.jpg) (http://s8.photobucket.com/user/bren1973/media/WIN_20150531_182228_zps7uy0bpea.jpg.html)
I found a 2x15 cab on cl. its an acoustic model 106. any information would be helpful. the dude is only asking 150 and he is throwing in an acoustic head that may or may not work.
ive been hunting for a 2x15 for awhile. maybe this is the one. im waiting for him to get back to me with condition etc.. naturally there were no pics or much information in the ad.
Get it. Send me acoustic head.
can you fix it and send it back??
help needed. as you guys know, im pretty clueless when it comes to electronics/electric stuff, among other things.
heres the issue. i have a stock fender jazz bass with one mod. i had both pick ups wired together so the controls work like a p bass. one tone and one volume. recently ive noticed that at any volume [the louder i turn it up, the more pronounced it gets], the bass has a terrible hum/static issue with the tone setting rolled to the full treble side [which is where i play]. if i roll to the full bass side of the knob the hum/static goes away. i also noticed a lot of static/crackling when i turn the tone knob. is that pot fucked or maybe something else?
thanks in advance.
I dunno how broken it is. If you wanna pay to ship it, ship it.
Quote from: mortlock on January 07, 2016, 01:30:27 PM
help needed. as you guys know, im pretty clueless when it comes to electronics/electric stuff, among other things.
heres the issue. i have a stock fender jazz bass with one mod. i had both pick ups wired together so the controls work like a p bass. one tone and one volume. recently ive noticed that at any volume [the louder i turn it up, the more pronounced it gets], the bass has a terrible hum/static issue with the tone setting rolled to the full treble side [which is where i play]. if i roll to the full bass side of the knob the hum/static goes away. i also noticed a lot of static/crackling when i turn the tone knob. is that pot fucked or maybe something else?
thanks in advance.
Could be a grounding issue. Does it go away when you touch any of the metal parts on your bass?
I have a Sound City 120 that suddenly had the volume cut almost completely out. With everything on 10 you can just barely hear it if you stand right next to the cab. There's nothing wrong with any of the cords or guitars being used, and the cab works with other heads so that's not the issue. Any ideas?
Quote from: beerrhino on June 06, 2016, 09:28:24 AM
I have a Sound City 120 that suddenly had the volume cut almost completely out. With everything on 10 you can just barely hear it if you stand right next to the cab. There's nothing wrong with any of the cords or guitars being used, and the cab works with other heads so that's not the issue. Any ideas?
Could be a dud valve, but it could also be any connection in the signal path failing. Putting everything on 10 makes for a bunch of other stuff going wrong subsequently. Could be a loose impedance selector too.
Anyone know if the Ehx small clone is a battery hog? Or should I start looking for shorts?
It's been years since I bought power tubes (EL-34s). Any insight into what's good? I recall the landscape with quality changed a lot. I think JJs were coming around when last I picked up a quad. Mullards sounded better, but didn't last as long as Svetlanas. Any new experiences?
Crickets...
Quote from: Pissy on February 01, 2017, 03:33:24 PM
It's been years since I bought power tubes (EL-34s). Any insight into what's good? I recall the landscape with quality changed a lot. I think JJs were coming around when last I picked up a quad. Mullards sounded better, but didn't last as long as Svetlanas. Any new experiences?
I've got Mesa Boogie tubes in my Orange AD30, i like them.
Quote from: Pissy on February 08, 2017, 06:26:24 PM
Crickets...
I had el34s in my traynor bass masters, had a bias mod added (sort of pricey) to both, put in JJ 6550s, and will never ever fucking waste another penny on an el34.
Did you get the JJ's from Eurotubes?
i got an ampeg rocket bass 1x15 combo. i turned it on and it wouldnt turn on. no pop or noise or anything. any ideas what just failed?
Fuse? But why?
i dont see where there even is a fuse. unless you got to open things up surgery style.
Is there a removable power cord? Check that. Is there a pilot light? Does it come on and no sound? Can you access the speaker leads? Are they tight? Can you access the back of the speaker? With clips to attach a 9 volt to see if the speaker moves or makes a sound?
no on the power cord.
no on pilot light.
did not come on. no sound.
cannot access speaker leads without major surgery.
no idea if they are tight. cannot access.
no access to back of speaker.
no access to 9v.
Have you verified it's even getting power if there's no pilot light?
I just looked it. It has a blue pilot light right by the switch. It just doesn't come on?
Is it used?
Ive owned the amp since new which is about 18 or 19 years. Its been a workhorse. The blue light went on i played through it, then i switched it off to hook up a fx pedal and when i went to turn back on, nothing. Completely dead. I plugged a dif amp into exact same outlet and it was fine.
Internal fuse would be my guess. No smoke right? If not that then something else with power delivery. Cracked solder joint or something.
Does it have a breaker like thing to reset? Pics?
Not mine but this is the one i have. Internet pics.
No smoke, no pop, no nothing.
(https://i.ibb.co/pwjhGvX/iomb8k.jpg) (https://ibb.co/pwjhGvX)
(https://i.ibb.co/dD1PXMH/ampeg-100r-rocket-bass-combo-amp-360-783f89a6286003716a98a4cc42582671.jpg) (https://ibb.co/dD1PXMH)
No obvious breaker to reset.
I would give everything the wiggle test. Wiggle cord at outlet when plugged in, wiggle power switch. If that doesn't show you anything then it's time to get the screw gun out and partially disassemble to do a visual. NOT PLUGGED IN. There is almost definitely a fuse near where the power comes in by the power transformer/power cable entry.
If you're not comfortable with that or even going further with the chopstick test with power on DANGEROUS then you gotta seek a tech.
if you're concerned about your prostrate just wait till you start digging around inside an amplifier pretending to do your own tech work - things could really puff up quick. Nice piece of iron haging off the back of it though. :D
oh my
https://music-electronics-forum.com/forum/amplification/guitar-amps/maintenance-troubleshooting-repair/35747-ampeg-b100r-power-transistors-saturating
how would i convert that combo so it just functions as a speaker cab? how do you install a 1/4 in jack to the existing speaker?
i want to pull out the head and power the cab with a different head.
It's very possible to salvage pretty much everything you need to do that from parts from the amp section. Mono input jack, screws, backing plate material and the speaker wires are probably long enough too. You just have to possess the know how and done soldering skills and the tools of course.
There's plenty of stuff online regarding how to wire a mono speaker jack. I'd come over and help but you got Covid probably. And you live 3,000 miles away.
if you remove the tone pot from a fender p bass. how does the pickup naturally sound. is it treble side, bass side or in the middle? what determines that?
Quote from: mortlock on May 02, 2022, 07:58:09 PM
if you remove the tone pot from a fender p bass. how does the pickup naturally sound. is it treble side, bass side or in the middle? what determines that?
Probably the value of the capacitor.
So a resistor in parallel with a capacitor creates something called an RC circuit. An RC circuit has a unique property related to AC signals that allows passage of the signal through the capacitor from a specific frequency and beyond.
The values of both the capacitor and the resistor determine where in the frequency spectrum that point occurs. It's called resonance.
In a guitar, the signal from the pickup is full spectrum- basically- until it gets to the tone RC circuit. Since the resistor in that parallel RC circuit is a potentiometer, the frequency point changes based on where you twist the knob. With a tone pot, those upper frequencies are peeled away from the signal and allowed to pass through the RC "gate" to ground effectively removing them from the signal going to the volume pot, and ultimately the amp.
If you pull the tone pot and that cap out, it's much like turning the tone knob all the way up. But not 100% exactly because the presence of the components colors the sound a little, for better or worse.
Most all tone circuits on amps or guitars or even stereos for that matter use this same principle. Coloring the sound by being selective about what is removed, vs adding boost to any specific frequency range.