Snap, crackle, pop from UNPLUGGED amp?

[Mrd34d]

I was just playing for a while through my frankenrig, shut down, unplugged both amp heads and went for a smoke.

Wife text me a few minutes later saying that it was making random pop & crackle noises....but everything was off and unplugged from the wall!!

The set up is a 1970 Traynor YVM-4 80watt PA head, Gorilla TC-65 (head convert), a Hughes & Kettner BC210, and two Traynor YSC-3 column speakers.

I had bass to the Gorilla with speaker out to the HK BC210, and the gorillas preamp out to the Traynor channel 1 input. I then went from the HK BC210 to one column speaker, and the second column speaker directly to the Traynor head.

Honestly it sounded great! Especially with two reverb tanks on low and the tube screamer gain on the gorilla up 1/2 way.


Could this be stored energy In the paper caps in the Traynor? could it be something in the HK BC210?

I'm ruling out the gorilla...honestly it's been amazing.

Any Ideas?

 

[Mrd34d]

Meep

 

[beans-on-toast]

Amps can make noises when you turn them off.

In general, tubes can ping as they cool, this is not uncommon. Sometimes tubes will do this when they are new. Others will continue to do it. It there is a stress in the tube, it may or may not lead to damage down the road. I wouldn't worry about those issues.

Some amps are designed to discharge their caps through a pathway to ground when power is no longer applied. They can make a sound when doing this. Some caps will make a high frequency whine as they are charging. Be aware that there is still energy in an amp, even with it turned off and unplugged and that energy can be dangerous.

 

[Mrd34d]

Both amps are solid state. I do get what you're saying though.

I flipped both amps to the on position while unplugged in hopes to discharge the caps

 

[beans-on-toast]

I flipped both amps to the on position while unplugged in hopes to discharge the caps

Sometimes that helps. A fast way to discharge caps on some amps is to play some hard notes as you turn off the power. If it is working, you will hear the notes distort as the caps drain. It won't drain them completely but will greatly hasten the process.

 

[Mr. Foxen]

Probably metal cooling noise if been running them hard or they are overheating from being old.