I just recently purchased on of these with a really low serial number (called Mesa and they said it was probably made around December '82) and am trying to get some feedbac/suggestions from people on here who have had or has one. The cascading distortion on here is AMAZING! Hands down BEST bass fuzz I have ever heard. Doesn't suck all the low-end outta the bass. I recall reading another post on here about this about and the owner nearly epoxying the knobs in place. The Master on here if moved a hair jumps like 10dB seemingly. I would love to be able to use it as a two-channel amp and last night tried running an older (passive?) AB box to each channel. When doing this though and if running in Channel A (overdrive input) the volume drops to nearly zero but if you unplug the Channel 2 input, the volume jumps right back to where it is supposed to be (i.e. loud). Seems like there is some sort of circuit design that doesn't let you AB the channels in this way to get a rich fuzz channel (Ch1) and a great clean tone (Ch2). Any feedback etc would be much appreciated. I thought of taking it to my amp guy to see if he could customize it to work the way I want it to. Would a non-passive AB box be the way to go?