This amp is everything the Princeton should have been and more. 2. 12ax7 2. 12at7 preamp section, 4 6v6 power section for a switchable 40 or 20 watts of classic american tone. The layout for this classic beauty is, volume, 3 band eq to really dial in the tone you need, a tweed knob (this bypasses the tone stack for some really awesome breakup/early tweed tones), a master tone knob.