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Help my Amp Died (Fixed now, Thanks for your help BRB)

PostPosted: Wed Jan 17, 2007 2:43 am
by stratman_27
I've got a Peavey Classic 30 and tonite at rehearsal it wouldn't work. Here's the symptoms:

1. Power light comes on
2. No ouput through clean channel
3. Minor output in lead channel (if you crank it to 12 it has about the same output as the amp has on 1 or less. Meaning you can hear it but just barely.
4. No hiss, no hum, no sound

Checked speaker connection--good
All tubes glowing

What do you think guys? Tubes?, Output transformer? Fuse?

I hate to lose this one. It's a jewel and I have no current backup

PostPosted: Wed Jan 17, 2007 3:03 am
by guitarslim101
Sounds like a fuse to me.

PostPosted: Wed Jan 17, 2007 3:55 am
by thebluesbox
the fuse isnt on the power line? Wouldnt the amp not turn on at all?

PostPosted: Wed Jan 17, 2007 4:02 am
by songdog
I would think if the light is on then the fuse is OK.

First you might try reseating the tubes (with the power off). Then testing or replacing the tubes. Got any spare tubes you can sub? I always keep a spare set laying around.

PostPosted: Wed Jan 17, 2007 5:48 am
by ricochet
Keeping a set of spare tubes is a mighty good idea. There's a reason those things plug into a socket instead of being soldered in.

Go over to and in the menu on the left, click on "Guitar Amp Tech Pages." You'll then see a link to a "Tube Amp Troubleshooting Guide" that's excellent.

PostPosted: Wed Jan 17, 2007 8:00 am
by JLynn
I have a classic 30 that's been misbehaving a lot lately too. It cuts in and out where it'll be working fine and then go to a 1/4 volume mode. Very annoying. A friend kept telling me it was probably the effects send/return jacks getting faulty so I grabbed a 1/4" patch chord and jumped the loop....and ya know what? So far it has been working perfectly. I'm keeping it in there for now until I can get around to pulling it apart but for now it's a temp fix. The 30's are insanely complicated to work on, especially if you want to get to the send/return jacks so I'm in no hurry.

PostPosted: Wed Jan 17, 2007 10:09 pm
by stratman_27
Working now. One of the preamp tubes was bad. I swapped out the three JJ's for the EH that came factory installed and she fired right up. Don't care much for the tone from them but at least it was a tube and not an transformer or something more serious.

PostPosted: Wed Jan 17, 2007 10:49 pm
by jeffl
Hey Stratman,have you read Steve Ahola's ( ) articles on modding the Classic 30...? I own a 30, and I found these articles fascinating. Judging by all the work he's done on Classic 30s alone, I wouldn't think the guy would have time to do anything else (unless he eats a baggie of black double-dexies every day). If you go to his site and click on "Articles on Guitars & Amps" in the left column, and then scroll down to the second section about "Articles on Guitar Amp Mods" and click on the 4th one down, you'll find 52 articles in pdf form concerning modding a Classic 30. Even if you never wanted to mod one in any way, you'll find that he passes along alotta knowledge about the marvels and horrors lurking under the switchplate. I learned a few things in there,without reading every line of the articles.

PostPosted: Wed Jan 17, 2007 11:20 pm
by stratman_27
I downloaded and printed off the 52 page PDF and took it to one of our electronics maintenance guys at work. He took it home and came back saying that all could be done relatively easily if it weren't for the layout of the inside. I had my chassis out for the first time ever last nite and I was amazed at the layout. Needless to say he wasn't really interested in working on it even on a per hour fee. This guy used to do amp work for a local music store and currently does TV repair on the side. It didn't look to me that Peavey intended for average joe to work on these things and until I have a solid backup I'm content to play it as is. A set of JJ tubes really wakes these amps up but I can only imagine getting the mods Aloha has done. These amps are also well served by a speaker change so I hear. Haven't done it yet but I'm debating on either a Greenback, or a Vintage 30 or the Eminence equivalent.

PostPosted: Thu Jan 18, 2007 2:32 pm
by jeffl
It sez right in one of the articles that there's a lead to some tri-folding circuit card stuffed up in one of the spaces in the chassis that will probably break when you take it out,unless you're lucky. There are about three SS components on that "all-tube" amp (lol!),including the rectifier and some parts of the reverb and fx circuits (I'm doin' this from memory,so I could be off a little). The impression I got from previous discussions I've read is that the 30 is a fine amp,unless you have to move that goofy circuit board. Maybe there's a trick that's been developed by now...I'd get aholda Ahola (his contact info's on the page) if you have questions. My 30 has never gone down,but I do keep a coupla spare tubes around for it,in the bag,and I don't put that many hours on it.

PostPosted: Thu Jan 18, 2007 2:45 pm
by 601blues
:lol: For the older guys here, Remember when all TV's were tube drivin??you could go into most stores and they had the huge cabinet of tubes and a tester so you could test and replace your radio,tv, and amp tubes in a jiffy!!Just like pickin up Bread and milk!!!

PostPosted: Thu Jan 18, 2007 5:42 pm
by jeffl
601blues wrote::lol: For the older guys here, Remember when all TV's were tube drivin??you could go into most stores and they had the huge cabinet of tubes and a tester so you could test and replace your radio,tv, and amp tubes in a jiffy!!Just like pickin up Bread and milk!!!
Yeah, and the radios were tube driven,and the film projector amps,etc. One of my uncles was a repairman for a department store in Altoona,Pennsylvania, and his son John picked up his skills. My cousin was building transistorized radios outa clear plastic 4" X 6" fastener boxes from the hardware store back in the early 60's,before you could even find 'em in all the stores. My cousin still has thousands of tubes that his dad left behind when he died.

PostPosted: Thu Jan 18, 2007 5:50 pm
by ricochet
Tubes rock!

Steve Ahola's a very nice guy. Dunno about the Dexies, but he sure stays busy. I like to read his stuff, but I don't want to try modding these modern amps much. Printed circuit boards are things of the devil. Eyelet and turret boards are only a little better. Amps should have galvanized steel chassis and loose point to point wiring running to terminal strips.