it started with the mid knob. in channel 2 the distortion texture would go from a tin can filled with angry mosquitoes with the mid at zero, to double-barrel flame thrower.
then the mid knob died and its stuck on mosquito mode.

i've taken it to 2 techs. the first one said he couldn't figure out what was wrong. the second one took it, and i think he just cleaned it out and put a new tube in the V2 position. aparently V2 powers the tone knobs

now it seems like the treble and bass knobs are dying. i don't hear them doing much of anything. and the presence knob doesn't seem to do squat either. and it seems that the problems are only in channel 2.

i'm about to take it to a 3rd person, but this is really pissing me off. i've already sunk $130 into this crap.
Well, personally, with any Mesa amp, I wouldnt consider sinking $130 into it to be "crap" i would think of it as pocket change compared to what you probably paid for the amp.

It sounds to me like either the pots need to be cleaned...or they are shot altogether.
I've bought, sold, and traded more gear than I care to admit.