peavy classic 30 popping noise

[vanwaltly87]

I have the on/off popping noise, I under stand that it is just amplifying the spark from the switching to off position.

The problem is that I was playing and I had a volume loss and a loud popping and crackling. I thought it was a bad cord, so I kicked them around.
Upon disconecting everything from the amp, it popped on its own, leaning it over I tapped on the reverb tank lightly, and the popping continued, not the reverb sound.

Could this be just a loose tube, or a bad wire leading to the reverb tank? It happens at random, and no sound comes, then it comes back, with signifigant volume loss.

[Enzo]

On/off popping only occurs when the switch is thrown. If the amp pops and crackles on its own sitting there, the most likely thing is the power tubes are failing. How old are your power tubes?

Power tubes are the four longer ones - EL84.

[vanwaltly87]

I thought that too after I started reading about the tubes. I tried the pencil eraser tapping trick, all of them make that tube rattling sound, but one of the Pre-apm tubes (12AX7) continues to pop when I tap it. I assume that means its bad? I didnt think that unless I was on the drive chanel that a preamp tube would cause a volume loss. But I suppose there all run together in series?

[Amp Kat]

Popping could be from any tube but is usually confined to the power section. If you can wiggle the tube and make it pop it is possible that the socket may need changing or the tube is bad . If you swap tubes and it still does it in that same position then it's most likely the socket.The C-30 uses V1A and V1B as it's gain stage before the tone stack and the drive channel uses V1 & V2 before the tone stack. If you do all of the mods on The Blue Guitar page and Enzo's tube rattle stopper the amp will be much better and reduce noise and your performance will increase.

[vanwaltly87]

Does the C-30 have a fixed or adjustable bias? Im not sure how to adjust it if its not fixed so I need to know.

[Amp Kat]

Fixed bias with no adjust. Plug and play.

[vanwaltly87]

Thanks. I may replace them with Electro Harmonix or more JJ tubes. What kind do you suggest? I play really mellow music (post-rock), but I like my drive chanell to shine when I play leads.

Walt