I posted a thread yesterday asking for help with my Super Reverb. When I was trying to answer some of the questions asked by responders I realized that my knowledge of even basic tube amp technology is lacking. What would be a good book for me to get started? I would like to be able to do my own simple diagnostics and repairs. I realize I will probably never be a full technician, but if amps were cars, I would like to be able to change the alternator and serpentine belt.