Just got a combo amp via a TGP'er. Need to fiddle with it a bit before I really comment, but I think it'll be a keeper. I need to loose the G12H30 speaker tho', the amp is too bright with it. Will swap out the stock tubes too. BUT - what does the adjustable pot inside the amp (where all the wires/caps/innards are) do? Is this any kind of tone adjustment? Or is it for biasing? Also, what exactly does the flattening/dampening switch do?