Years back I was in a cover band with a guy who played a strat thru a cranked twin
that he had up on a chair. Icepick tones were his thing and every time I'd walk by
the front of his amp my teeth would start hurting.
I can visualize exactly the sort of scenario you are explaining. I had a buddy that was a great lead player, but had the worst, overly-trebly tone I ever heard. For months, I just wanted to hide a Wah in his FX loop, and lock it in the heel-down position without him knowing.
Eventually, the desire to help him turned into rage. I went and bought a Whammy pedal, and cranked the channel volume (I was playing a Triple Rec at the time). When he walked in front of my rig, I hit the most glorious pinch harmonic ever, engaged channel 3, and then slammed the Whammy to the floor. The high pitched squeal at full volume made it feel like an ice pick was chipping away at our ear drums. I told him this is what it sounds like when he played lead.
From there on out, he always made sure to EQ some bass/mids into his rig...lol.
To piggyback on this story, this all happened in his garage at his parents house. His sister lived there too and had a pet ferret. When I hit the Whammy/harmonic, the ferret (who happened to be sleeping in his hammock at the top of his 4ft cage) was startled so bad, that he fell out of his hammock and crashed down to the bottom of the cage. Poor ferret.
Maybe this is why I always opt for 150w-180w amps...
