one more, well, two more questions. the amp uses 3 pre-amp tubes. when changing to a different tube, do you have to use the same type in all three positions, or could you use a different one for each position. Also since the amp is a 3 channel amp and uses 3 pre-amp tubes, does that mean that each channel has it's own pre-amp tube? that might be a stupid question, but hey, you never know if you don't ask. Thanks for the info.