The gear is a peavey prowler amp I found locally, which I understand is almost identical to the valveking board. Initially sounded alright gain wise, I opened this up and found several funny modifications, most of which I couldn't identify. I changed several as close as I could get back to original schematic values, but my current gripe is the clean channel. It sounds alright until it breaks up, this clean has the most abrasive and sharp breakup imaginable. My pickups are pretty high output, but damn, right when I lay into the strings a little the amp smacks back with this explosive pop that really hurts the ears. Supposedly this amp has a great clean channel so Im assuming some ill-advised mod is responsible for this.

My question is, if I want the clean channel to break up gradually and smoother, where should I start on the circuit board? I can handle small electronics well enough but I don't know amp architecture too well.