Crackling sound L channel

[EraserXIV]

I'm getting a crackling sound in the L channel and it doesn't change with volume. It is intermittent, comes and goes, and there doesn't seem to be any pattern to it. It occurs without any source plugged in.

One thing I noticed is that it occurs less often if I put my hand on the top plate and hold it there. I'm thinking some sort of EMI or RF interference? Or maybe a ground issue? I'm not too sure, any help would be appreciated, thanks.

[Paul Birkeland]

If you painted both sides of the top plate, you might scrape some more paint away around the screw at terminal 3 and the ground screw by the power transformer.

Otherwise, I'd tighten those screws down a little more anyway.

You might also pop a different 12AU7 and 6080 in, just to rule that out.

-PB