Does anyone own one of these and use it for bass? How do they sound? WIll they work well stock, or do they need to be modded to sound good? Any info on preamp tubes? There's very little info on these amps floating around. It has four KT-88's in the power section, and it has six channels with volume, bass and treble and also a master volume. I'd appreciate any help here, as I have been offered one of these in a trade, but haven't had a chance to try it yet. Just interested to hear what people think. Thanks!