I'm having a bit of a problem with my 95 fender bd. When I power up the amp, and start playing sometimes everything works fine...but sometimes I get a very loud crackly sound, almost like a speaker issue, the volume will also drop out significantly. I've noticed it's much worse when I play harder. I thought at first it was poss. a speaker issue, so I plugged an ancient boss me-30 into the effects return, to only use power amp
and speaker. No problem whatsoever(it actually had a pretty decent, extremely loud sound to it). So I bought a new set of preamp tubes, thinking it might be a preamp tube
problem-the tubes I believe were the originals, new ones needed anyway. I also noticed that when I adjust the presence knob, the problem will start immediately, if it's not happening yet. I'm thinking it might be a cold solder issue or a loose tube socket.