Repairing a Bl@nkenshib

[Sir Cuitous]

I can hear a good sounding amp in here, but this amp has some problems. It's a totally custom design, so I have no schematic. Still, it bears a lot of similarities to Fender designs. I am attempting to tackle one thing at a time here. The general symptom is crackle with an occaisional pop that is occuring with no signal. Also, when the volume is turned up, the amp will start to FB, which is weird. I believe a resistor may be arcing somewhere. I tapped the resistors from the beginning of the signal path and found a 3.3M resistor and the wire from pin 7 of third tube (driver -> PI?) that seems to be microphonic?!? Other resistors seem solid, but this one creates an audible tone even when the volume is zero. This amp has reverb, but no vibrato. This resistor looks as if it decouples (correct term?) the reverb circuit similarly to Fender reverb designs.