#1
TL; DR: Old Peavey Classic 50 head, scratchy, static, squealing noises, not tubes. Took it to a tech who didn't fix it. Any thoughts on what it could be and how to fix it?

Right. So several years ago, I bought a Peavey Classic 50 head used off of ebay. It is an older model (obviously the head is no longer in production), made before they incorporated an FX loop. Anyways, the problem arose not long after I got it. I noticed that it would intermittently make scratching, staticy, sometimes squealing noises. The noises would get quite loud at times, but you could always hear the guitar clearly, just with the noise as well. So, I began to check through my gear. It did it with all of my guitars, cables, and speaker cabs. So, I asked around and decided it might have been tubes. So I got new ones (which I regret getting now b/c they're Sovtek). Problem persisted. Took it to a tech here in central Arkansas. The first time, he cleaned the amp out. Still did it. The second time, he fixed some small part (not sure what) that was overheating. So, I decided I could just live with it (if it was a loud enough gig, the noise wasn't too bad). I bought other amps over time and the Classic 50 was relegated to mothballs. It sat for a few years, not being played more than a few times over that span. Recently I got it back out and played it, and I really liked it. I opened it up and cleaned a little dust out of it myself as well. If I could get rid of the pesky noise, it would definitely be a gig-worthy amp. So, I'd like to see if anyone has any ideas as to what else the problem could be. If and when I can free up some cash, I may just take it back to the tech man and tell him to keep it until he can fix it, but any of your suggestions are welcome.
Ibanez UV777 - Carvin TL60 & 727 - Jackson KE3
Splawn QuickRod - Mesa Stiletto & RoadKing - Peavey Ultra+ - Peavey Bandit
Some pedlulz & cabz


7 String Legion
#2
Honestly? Try a different tech. This sounds like it should be a pretty simple fix, maybe it just needs a different set of eyes looking at it, you know?

Dumb questions: Did you still get the noise when you plugged straight into the amp? (No pedals, etc). Did the amp make this sound in different places/rooms/etc?
Telecasters-->Dunlop Volume Pedal-T1M Pearl-AMT Japanese Girl Wah-Line 6 M9-Ibanez DE7-EHX Cathedral-->Mesa Boogie Nomad 4x10 combo
#3
Do all of the controls on the amp function correctly? Do you get any scratching noise when you mess with the controls?
#4
Sorry, I shoulda been more clear. Yes, it did do it always, no matter what I had plugged into it. Pedals or not. Played it today straight in and it did it. No matter where the amp is, no matter what's plugged into it, the background scratch persists.

Taking it to a different tech guy would be the obvious solution. Problem is, central Arkansas is piss-poor as far as amp techs go. But I'll ask around and see if anyone else's name pops up.

Basically, what I'm asking is if anyone with some tech know-how can say what the problem could be, so that when I do take it to a tech, I can know what to ask him to check. I don't expect it to be a problem I can fix myself.

EDIT: yeah I also checked the controls and stuff. Some were a tad scratchy when I moved them, BUT, the background scratch didn't seem to be affected at all by ANY setting on any control. No matter where I set the controls, the scratch persisted.
Ibanez UV777 - Carvin TL60 & 727 - Jackson KE3
Splawn QuickRod - Mesa Stiletto & RoadKing - Peavey Ultra+ - Peavey Bandit
Some pedlulz & cabz


7 String Legion
Last edited by BCKRedBaron at Jan 23, 2012,
#5
Could you describe the sound in detail? It cooooould be (I've seen this once before) that some part of the amp has become "exposed" (I forget the proper terminology), and is picking up radio signals/noise from electric sources.

Do you get more noise when moving the amp's knobs?
Telecasters-->Dunlop Volume Pedal-T1M Pearl-AMT Japanese Girl Wah-Line 6 M9-Ibanez DE7-EHX Cathedral-->Mesa Boogie Nomad 4x10 combo
#6
Ok, I can't make out any kind of radio signal, such as a voice or music. So, it could be that, but it just doesn't sound like that when it typically happens (like picking up an AM station from Mexico). I don't get more or less of the background noise when the nobs move, just a little scratch on some of the pots. From everything that I can tell, the noise seems to be independent of the control scratch.

As for the noise itself, it does resemble the sound you get with moving a scratchy pot, but it's persistent, and it sometimes varies in volume. It usually starts within a couple minutes of turning the amp on. At times it takes on a faint, high pitch squeal amongst the scratching. Also keep in mind that the noise doesn't seem to interfere with the guitar signal itself. I can still clearly hear what I play through it, just with the noise in the background. I wish I had some way of recording it, to help communicate the sound a little better, but I'm outta luck there for the time being.
Ibanez UV777 - Carvin TL60 & 727 - Jackson KE3
Splawn QuickRod - Mesa Stiletto & RoadKing - Peavey Ultra+ - Peavey Bandit
Some pedlulz & cabz


7 String Legion
#7
I have the same issue as you. You description AND what you have tried is about what happened to me. Have you figured this out yet? I did notice when I tapped my finger on the on/off light the pop will sometimes stop. Then return. I was thinking a switch is bad...Let me know if you ever got it fixed?
Thanks!!
Mike
#9
If you're wondering about picking up random radio noise:
Cover the whole head in tin foil and see if it still does it. If it stops, you've been picking up signals. If it stays, it's something else.

Also: Find a new tech even if it's a huge drive.
.

Remove V1 & V6. Put the 12AX7 from V1 into V6 and leave V1 empty. Try the vibrato channel.
Last edited by woad_yurt at Feb 23, 2013,
#10
Sounds like it could be an issue with the circuitry, maybe a bad cap or transformer
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