Issue with Peavey C30

[kfowler8]

I have an older Peavey Classic 30. I'm guessing it's a late 90's / early 00 model. I bought it used years ago. I hadn't used it much lately and after recently cranking it up, I've noticed some issues.

Here's a list of issues:
- I hear a crackly sound when I turn any of the pots. Doesn't matter if it's eq, reverb or gain. First I thought it may have to do with dirty pots but not so sure since it's on all of the knobs.
- I noticed at really low volumes, the amp seems to fade in and out. If I crank it up past 2, it seems to go away. I really notice it on the OD channel.
- The reverb seems to work sometimes and not others.

Other info:
- I swapped the original 16 ohm speaker out years ago with an 8 ohm Celestion. I just read recently that I should have been running a dummy plug in the extension outlet to make it run at 8 ohms. I've also ran this amp with an 8 ohm speaker and a 16 ohm speaker in an ext cab. Now knowing the error of my ways, could this been the source of my current problems? Bad transformer?
- The tubes have never been replaced. They must be 10+ years old. I'm planning on swapping them out but could this be the simple cure?
- I need to do some more experimenting but can the fx loop in the amp cause some of these problems?

Thanks,

Kevin

[stvnscott]

I see two symptoms of at least one bad tube. Crackling on the pots means one or more preamp tube grids could be leaking DC. Fading in and out usually indicates one or more failing tubes.

Mismatching the impedance can kill cheaper OTs, but good ones can stand up to the abuse. Not sure which you have. Sometimes a mismatch sounds better. Sometimes worse.

[kfowler8]

Originally Posted by stvnscott

Mismatching the impedance can kill cheaper OTs, but good ones can stand up to the abuse. Not sure which you have. Sometimes a mismatch sounds better. Sometimes worse.

OT = Output Transformer?

Thanks for the reply. The tubes are what I'm thinking. They're the original Sovtec. I was going to call Eurotubes this week and get a new set.

[TweeDLX]

Tubes are the first thing to suspect. Not a bad idea to also clean the input, speaker, and FX loop jacks. Crud can collect over the years, especially if it's been sitting unused. May not be a problem, but it certainly won't hurt.

[rockon1]

Originally Posted by kfowler8

I have an older Peavey Classic 30. I'm guessing it's a late 90's / early 00 model. I bought it used years ago. I hadn't used it much lately and after recently cranking it up, I've noticed some issues.

Here's a list of issues:
- I hear a crackly sound when I turn any of the pots. Doesn't matter if it's eq, reverb or gain. First I thought it may have to do with dirty pots but not so sure since it's on all of the knobs.
- I noticed at really low volumes, the amp seems to fade in and out. If I crank it up past 2, it seems to go away. I really notice it on the OD channel.
- The reverb seems to work sometimes and not others.

Other info:
- I swapped the original 16 ohm speaker out years ago with an 8 ohm Celestion. I just read recently that I should have been running a dummy plug in the extension outlet to make it run at 8 ohms. I've also ran this amp with an 8 ohm speaker and a 16 ohm speaker in an ext cab. Now knowing the error of my ways, could this been the source of my current problems? Bad transformer?
- The tubes have never been replaced. They must be 10+ years old. I'm planning on swapping them out but could this be the simple cure?
- I need to do some more experimenting but can the fx loop in the amp cause some of these problems?

Thanks,

Kevin

The FX loop can cause fading in and out. A cable in the loop will virify that one way or the other. Dirty pots can get scratchy. A can of contact cleaner will tell if thats the case. I'd do some "routine " maintenance and see how it plays .

1) Clean the pots,tube sockets(non-lubricated) and jacks with lubricated contact cleaner. Radio shack stuff works well,yes,it does.
2) Change the tubes. Be kind to it.

If it still has isues it might be a broken jumper that connects the folded up PCB boards however it sounds like its been a while since its seen some TLC. Bob

[TweeDLX]

Nicely said Sir Osis!

[rockon1]

Originally Posted by TweeDLX

Nicely said Sir Osis!

Bugs Bunny cartoon- The seen with the knights of the round table. One of the placards said-Sir Osis of Liver lol! Bob

[kfowler8]

Great replies guys. Thanks.

I did some further testing today when I had a chance to crank it up. No issues at all when running anything higher than 2 on either channel.

At this point I'm going to switch out the tubes and clean the sockets as recommended.

Thanks again!

[kfowler8]

Just wanted to say thanks for the help. I pulled the chassis last night and the 1 amp fuse had indeed popped. Everything works great now. Eurotubes is sending me a new EL84. They've been fantastic to work with. I highly recommend them.