Just wondering if anyone has ever seen this particular problem befo
When I exceed a certain output level, the volume begins to modulate from
normal to almost zero in a smooth, cyclic manner. This occurs at a rate
of around 0.5/S- almost like a very slow tremolo circuit. I haven't
cracked it open yet, but I'm guessing it has something to do with a
negative feedback circuit gone bad, or maybe just a power supply issue.
Whatever it is it only happens when the output level reaches a certain
(fairly low) amplitude. Below that it works fine.

Any guesses? Bad PS cap?

Thanks,
Sam