You do realize that Gary just launched an all new batter powered tube amp don't you?
It's a 15 watt per channel, stereo amp that runs on 12 volts.
It is unbelievable!
It's clean. It has great resolution. It's dynamic. It is not soft in the top or the bottom either. It has good drive and sounds like it has 50 watts or so on hand. And best of all, it is dead quiet. Like Art said, it is as quiet as a solid state amp, that's not turned on.
Oh yea, and they are $995 a piece. Then again, that might be the best part too.