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General Category => Jam Room => Topic started by: Pissy on September 16, 2022, 09:33:26 AM

Title: Amp Woes
Post by: Pissy on September 16, 2022, 09:33:26 AM
I have three Garnet heads.  2 50W and one 100W that I've always used as my bass amp in the band. 


Last time at practice, the 100W started warbling, like a broken tremolo was in front of it and the output was down to about 1/3rd.  Have to dive in, but bought new caps in anticipation that being clise to 50 years old that they may need to be replaced.  I very well may have messed up here by going by a schematic instead of looking at the amp, because the caps are different values.  Lower Vdc are installed than the schematic calls for.  I'm not surprised because the dude that did all of these back in the day took many if them back in and played around with them, making them unique.  He died in 2006.


No biggie, I thought.  I have those 50 W models that will work for BP, even if not for a live show. 


No dice.  One is blowing fuses, the other is quiet, though the tubes are lit.  I have three of these one off amps to fix now.  I have a course of action with the 50's involving tubes first, but not exactly full of confidence.  I might be playing bass through a Stewart power amp this weekend. 
Title: Re: Amp Woes
Post by: James1214 on September 16, 2022, 04:30:25 PM
I feel your pain. Do you have access to a sansamp? I always had one"just in case" it can make the shittiest Poweramp sound awesome in addition to being a killer DI.

Sent from my SM-N986U using Tapatalk

Title: Re: Amp Woes
Post by: RAGER on September 16, 2022, 07:11:56 PM
Don't mean to jinx but hope it isn't an OT.

My Orange has been a bit noisy at idle lately. I need to isolate it away from everything then check tube sockets. Just had it worked on couple years ago so it's probably just loose odd bits. Chopstick time.
Title: Re: Amp Woes
Post by: Pissy on September 16, 2022, 07:46:51 PM
So i took an old iPhone with an 1/8 jack and found a signal generator app.  Fed that into it and hooked up my scope.  I could see the jacked up signal, the good signal, and I'm pretty sure it's one of the caps.  On the 100w.  Bought some fuses for the smaller one that blowing them.  Pulled the tubes and tried it.  Still blew the fuse.  So that means it's before them, i think.  Sort of.
Title: Re: Amp Woes
Post by: Pissy on September 16, 2022, 07:52:49 PM
No sansamp, btw.  But I DO have an old Harmony H303A that I modded into a preamp that I can put in front of it.  I've honestly never really given it a test since the Garnets always were great. 
Title: Re: Amp Woes
Post by: Muffin Man on September 16, 2022, 08:00:12 PM
Saw a show in NY the venue had under stage subs and an Ampeg refrigerator on stage which I assumed the player was plugged into. After the show I mentioned how nice his playing and tone were. He was using a Line6 POD hidden somewhere, no amp head, straight into the P.A. I stormed out! haha
Title: Re: Amp Woes
Post by: Pissy on September 16, 2022, 08:19:11 PM
Lordfinesse is in a pink floyd tribute band, playing 2nd guitar and he does that.  No amp. A Firehawk thing.  Straight to PA. And it sounds great. No chiropractor.


Totally different setting than a three piece, blues based, instrumental, semi-improv, V8 inspired, space caravan thing though. 
Title: Re: Amp Woes
Post by: Muffin Man on September 16, 2022, 08:30:40 PM
ah yes, indeed!
Title: Re: Amp Woes
Post by: Pissy on September 17, 2022, 10:42:33 AM
One down, the pro200 is fine.  There's a three position standby switch that I forgot about.  Hadn't switched it all the way.  That'll be fine for bp. 


The other 50w, simply called The Pro, i think I found the problem there with one of the filter caps.  It's stained from the tar running out of it.  Pretty sure that one was replaced, albeit close to 20 years ago.  Bonus is that it's only used for one filter stage, so the swap out should be pretty simple, provided I don't mess up the connections.   Not like 8 different wires going to the same lug, or 4 wires all colored the same going to 4 different lugs that aren't grounds.


I got a full fay today, not sure I'll get to it, but a plan is in place at least. 


Ordered proper caps for the Odyssey.  $165. Ouch.
Title: Re: Amp Woes
Post by: Pissy on September 17, 2022, 03:17:52 PM
The 2nd 50w is working now.  That previous mistake I made ordering caps off the schematic saved me here.  I used one of the caps I bought to replace the bad one here.  It was a direct replacement for what was in there- which was replaced once already. 


Feeling a little better about my situation now.   I haven't fixed an amp in probably 20 years. Felt good to get my confidence back. 


My soldering iron is dead though. Gonna need to rectify that.  I had to use one of the junky Wellers like you get at HD. It worked, but those things run hotter than I prefer. 
Title: Re: Amp Woes
Post by: Muffin Man on September 17, 2022, 03:59:12 PM
now that you're done with that let's get to boiling those bass strings.
Title: Re: Amp Woes
Post by: RAGER on September 17, 2022, 04:16:01 PM
Boiling guitar strings in 1985-me
Title: Re: Amp Woes
Post by: Pissy on September 17, 2022, 04:45:23 PM
I've graduated from boiling them - which does work if only for a short time- to running them through an ultrasonic cleaner.  It works better. 
Title: Re: Amp Woes
Post by: Muffin Man on September 17, 2022, 06:20:11 PM
Quote from: Pissy on September 17, 2022, 04:45:23 PM
I've graduated from boiling them - which does work if only for a short time- to running them through an ultrasonic cleaner.  It works better.
wow! excellent.  Do you use any certain kind of nut sauce? I was going to use petroleum but stew-mac sells some kinda graphite wax at $16 purposed for the job. Also, if you'd advise, do you use any string treatment to prevent squeaks when recording? More for acoustic I guess.
Title: Re: Amp Woes
Post by: RAGER on September 17, 2022, 06:24:14 PM
Slow roasted guitar strings with Sicilian olive oil and Trapani sea salt in 2022-me
Title: Re: Amp Woes
Post by: Pissy on September 17, 2022, 06:27:25 PM
I don't use anything to curtail the string squeak.  I think that sound is rather human.   Nut sauce is mostly pencil lead, buy I did get something from Music Nomad that is a nut sauce, I haven't tried it though.
Title: Re: Amp Woes
Post by: Muffin Man on September 17, 2022, 06:46:59 PM
thanks Pissy. knew I came to the right place. I've got some graphite drawing pencils here.

wow Joe Glaser quoted at Music Nomad on the nut sauce. Joe pleked several of my guitars, had me in to watch him scan my bass, result was didn't need anything but slight trussrod adj, frets were level from the factory (shock). Other guitars got the plek nut and fret level.

oops off topic..will resume with Tele tales another thread.
Title: Re: Amp Woes
Post by: Danny G on September 18, 2022, 09:55:07 AM
I've always used a #2 pencil for nut lube (heh heh)

There's a plek shop in town I'll be taking my guitars and basses to.

Frets are getting pretty chewed up on them and my LP Studio could use a pro setup after 2 headstock breaks (after replacing the guts and new bridge pickup it is giving my Iceman a serious run to be my main gigging guitar and not just a backup)


Sent from my iPhone using Tapatalk
Title: Re: Amp Woes
Post by: Muffin Man on September 18, 2022, 08:51:57 PM
fair warninig plek isn't all and be all. I had mine done because stainless steel frets.  a slippery slope. Fretboard tension if replaacing OEM frets..caution, beware. Things change. alot.

My old tech swore ahgainst some of this new-fnagled nuttery. Also legit so depends on you, your feel setup...,
Title: Re: Amp Woes
Post by: Muffin Man on September 18, 2022, 08:58:06 PM
Danny, be sure you know what +- getting into doing anything with that Iceman fingerboard (btter options that plek?) be careful with choice, frets into fingerboard. Tension big dealio.
Title: Re: Amp Woes
Post by: Pissy on September 26, 2022, 04:32:08 PM
Fixed the 100w.  It was a filter cap.  I've replaced 2 of the four.  I'm reluctant to do the rest, but I need to. Such a bitch to unhook the leads on the components that hook to the tabs, and I'd rather not cut them. 
Title: Re: Amp Woes
Post by: RAGER on September 27, 2022, 08:15:33 PM
Rad!  Nice job.
Title: Re: Amp Woes
Post by: Pissy on September 30, 2022, 09:01:25 PM
Replaced two more caps, and then a resistor lead broke right right at the body of the resistor.  I have a set of resistors on order.  Also had to order another cap for the main power stages as I used that one for the 50 watt last week.  I'll get some gut shots to post. 
Title: Re: Amp Woes
Post by: Muffin Man on December 01, 2022, 03:51:56 AM
Re: (hifi stereo) amps. John Curl> "the human ear hears better than twenty*, I mean I know we do.."... (after 37:50+) I have 2 of John's' amps (designs) Birds of a feather! kibbles 'n bits

*"you don't hear it as a tone"..


Title: Re: Amp Woes
Post by: mortlock on December 15, 2022, 09:24:40 PM
i got 3 amps out of commish right now and it sucks.

ampeg rocket b 100 15 combo. played through it faithfully for over a decade with no issues. one day i flick the on switch and nothing happens. its just dead. no sound, no pop when i hit the switch. just nothing.

peavey kb300. the input jacks and both shot and short out. also some of the various knobs are not working properly.

peavey bandit 12. volume knob doesnt work. input jack shorts out.
Title: Re: Amp Woes
Post by: Pissy on December 16, 2022, 07:13:12 AM
Look for a fuse on that ampeg.  The other two, you can get some deoxit from guitar center to spray and work into the potentiometers.   The jacks you can see if the spring tabs need to get bent back so they contact better.  I've heard that Monster cables mess with jacks because they're over sized on purpose - in order to make better contact.  Problem is, when you go back and use a standard cable afterwards the jack has been stretched out. 
Title: Re: Amp Woes
Post by: RAGER on January 16, 2023, 12:27:03 PM
My Orange has been a bit noisy as of late. Crackly at idle especially when warmed up. Figured preamp tube or cold solder joint. Turns out it's both. Pulled out of the head box, belly up, chopstick in hand, other hand in back pocket just in case and started pokin. Yep one 12ax7 and a solder joint. Had a few SOVTEK 12ax7's in stock. Swapped it out and it's pretty quiet. I'll order a couple new JJ's and flow the solder when they get here.

I'm getting old or weak cuz those Orange cabs seem a lot heavier these days.
Title: Re: Amp Woes
Post by: Muffin Man on January 16, 2023, 09:49:09 PM
My hifi monoblocks has a crackle either tube, pot, fuse, or whatnot. It calls for ceramic SLO-BLO but has a glass init so going to the bench next couple weeks.

If a tube amp smells bad, that's actually good. They're the best. I'm sending my EL84 hifi monoblocks off to the manufacturer. They're 95% okay but I want them on their bench before I start tube-rolling with diamond plates (maybe) they got the o-scope and have the chopsticks to boot. All the values and NOS goodies. Pay to play. Kinda expensive but tbh tubes are worth it and this is sorta endgame, for one system anyway. And the 10 year cure. These are super stable (but run hot, adjustable bias points, so no foolin')

I meant to snap a pick of them glowing but they're already boxed. Lemme get em back for a portrait. Soon. Just lovely.
Title: Re: Amp Woes
Post by: RAGER on January 16, 2023, 10:57:10 PM
The smell of a tube amp is like....well, it's something sublime. And the wood, glue, and Vynide   
Title: Re: Amp Woes
Post by: Muffin Man on January 16, 2023, 11:07:06 PM
Quote from: RAGER on January 16, 2023, 10:57:10 PM
The smell of a tube amp is like....well, it's something sublime. And the wood, glue, and Vynide

Wow! Ah 'tis.
Title: Re: Amp Woes
Post by: RAGER on January 29, 2023, 04:26:42 PM
I got horned up talking about bass cabs in the other thread so I went to fire up the Super Twin on top of the 8x10. Crackle, fizz. What's that smell? 

Quick scan
(https://i.imgur.com/aegi8o6.jpeg)

Found it. Scorched resistor. Basically the choke cuz these don't use choke transformers.

Gotta order stuff. I'll change t out and see if it just failed cuz it's 50 years old or if it's something else.
(https://i.imgur.com/cRuPoqi.jpeg)

Oh yeah. RCA black plate 6l6's.

(https://i.imgur.com/3aWLax3.jpeg)

And a damn Peavey 12ax7 for that Mississippi Marshall sound.

(https://i.imgur.com/lCfnWWS.jpeg)
Title: Re: Amp Woes
Post by: Pissy on January 29, 2023, 04:30:15 PM
Haha. Peavey tube. 


I'm a little concerned about that ceramic resistor.  I didn't think they deteriorated over time like that. But 50 years, so...
Title: Re: Amp Woes
Post by: Muffin Man on January 29, 2023, 06:59:44 PM
Ok that Super Twin is cool. Thought I was looking at dual rectifiers but nope. I like solid state there anyway.

I gotta figure out this hammer on thing, easy enough, but cool sound.

at 5:03