PEAVEY Special 130 noise problem

[Shakey 1047]

I have just acquired this amp and it has developed a sort of crackling noise especially when I play the lower strings. It's not distortion but like as if its going to break up but doesn't. I by-passed the preamp and plugged my guitar into the power amp in socket and it still happens so I am assuming it is something in the power amp stage.
I re-soldered the components in the power amp and power supply stages but it is still there.
I would be very grateful for any help[ or ideas.
Thanks Dave.

[Jazz P Bass]

Next step.
Can you try another speaker?

[Shakey 1047]

Thanks Jazz, yes I already did that I have two of these amps so I tried the other speaker but no change. Dave.

[ReginaldBisquet]

I had a Peavey Heritage with that same issue. The root of the problem was when I changed out the power tubes and one of the new tubes broke the socket. Got some arcing and weirdness before the amp went silent. Several things got burned up along the circuit path from that tube socket. A lot of stuff had to be replaced and even then - when all looked good - there was still a capacitor that was burnt out and causing some weirdness exactly as you're describing.

So, I don't have an answer - but perhaps checking the circuit for blown caps or something not looking so great along the board?

[Enzo]

The Spec 130 is a solid state amp, no tubes.

Turn it on and set the controls as normal. Turn off the reverb. Ball up your fist and whack the top of the amp hard. Does the amp react in ANY way? It should ignore the whacking. If hitting the amp causes noises, there is a loose connection. Low note crackling sounds like possible vibration issue.

If the amp sits there making noises even while not playing, could be a noisy part. One trick is freeze spray. Circuit chiller spray is available from various electronic suppliers. You8 spray the board in small areas to freze parts. If they react, then something is thermally sensitive, adn we narrow down to what that might be by freezing smaller areas.

And it isn;t always electronic. Loose mounting bolts on the power transformer for example can cause noise. Really.