Amp Tech Thread / Ask a tech Q

Started by Hemisaurus, February 12, 2011, 05:36:46 PM

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Hemisaurus

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.

liquidsmoke

#326
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..

Hemisaurus

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.

VOLVO)))

Post a video, bitch!

Push all the boost knobs in.
"I like a dolphin who gets down on a first date."  - Don G


CHUB CUB 4 LYFE.

liquidsmoke

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.

bitter

not sure if you mentioned this previously, but do you use any boost pedals?
Oh Andy I'm gonna go over to mount pilot and worship Satan

liquidsmoke

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.

Hemisaurus

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.

liquidsmoke

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.

Hemisaurus

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.

liquidsmoke

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.

Hemisaurus

Well unless he's changed his policy, he'll let you demo that amp to your hearts content.  Go try it out.

liquidsmoke

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.

liquidsmoke

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.

MichaelZodiac

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
"To fully experience music is to experience the true inner self of a human being" -Pøde Jamick

Nolan

Hemisaurus

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.

MichaelZodiac

Thanks, it was the first option. Great bass.
"To fully experience music is to experience the true inner self of a human being" -Pøde Jamick

Nolan

VOLVO)))

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?
"I like a dolphin who gets down on a first date."  - Don G


CHUB CUB 4 LYFE.

Hemisaurus

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.

VOLVO)))

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
"I like a dolphin who gets down on a first date."  - Don G


CHUB CUB 4 LYFE.

VOLVO)))

works fine with an adapter, by the way. Ill pop 'er open and find the schem for ya.

Sent from my DROIDX using Tapatalk
"I like a dolphin who gets down on a first date."  - Don G


CHUB CUB 4 LYFE.

Hemisaurus



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?

VOLVO)))

Do I read that from the wall wart or the pedal? I need a "where to test" lesson... :D
"I like a dolphin who gets down on a first date."  - Don G


CHUB CUB 4 LYFE.

Hemisaurus

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.


Hemisaurus

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.