Dear all, I have recently purchased a Hayden 20W all-valve combo. I have replaced the stock speaker for a G12M 25w greenback (from my cabinet). Dramatic improvement in tone ! I am trying to understand the schematic which Hayden has kindly sent to me (I hope I am allowed to share it without issues). I understand some things, but have doubts. Amps has : - Channel 1 (Bass, Treble, Volume) - Clean - Channel 2 (Bass, Mid, Treble, Contour, Gain 1, Master 1) - Crunch - Channel 3 (same as above with Gain 2, Master 2) - Lead I have a lot of questions. I´m a pain in the ass, probably, but if someone could help me understanding some of them, I can go home and do the homework after. 1 - The voltage rating of the cathode bypass capacitor of V1B (C2) really has to be 300v ? (usually 25v to 50v is fine.) 2 - The voltage rating of the cathode bypass capacitor of V2B (C28) really has to be 630v ? As above, usually 25v to 50v is fine). 3 - V1B is the valve for Channel 1 - Clean. But, in the schematic, the plate capacitor goes either to the right AND to the left ! Does it have any impact on the tone of Channel 2 and 3 ? While playing channel 2 and 3, turning knobs from Channel 1 don´t affect the sound. 4 - Are Gain 1 and Gain 2 simple gain knobs after signal of V1B ? Like an AC30. 5 - Close to Gain 1 and Gain 2 there is an "LD" signal that goes close to Master 1 and Master 2 on the right of the schematic. However, Master 1 and Master 2 look like the "volume" knobs on many amps and not like the "typical master", usually a PPIMV. The signal goes from tone stack at the treble knob into the Master 1&2 pots. However, What´s the relation between the Gain and volume here ? Are they the typical Gain and Volume knobs in an amp without PPIMV ? 6 - What valve amplifies the patch of channel 1? V1B alone ? 7 - What valves amplify the path of channel 2? V1B + V1A + V2B + V2A ? 8 - What valves amplify the path of channel 3? Same as above? 9 - Why V1A, V2B and V2A have such different cathode resistors. The first ones should be around 1K and the last one 5K or 10K. But it´s not the case How can the best tone be achieved? 10 - What it the purpose of V3A and V3B ? 11 - Why channel 3 (gain 2) has much more gain than channel 2 (Gain 1)? 12 - Why channel 2 (Gain 1) has a dark tone and channel 1 or channel 3 (Gain 2) are brighter? 13 - The Stealth switch (20w - Stage / 3W - Studio) on the back seems like switching between resistors. What exactly is it doing? It works quite well. Is this a real attenuator? Thanks everyone. I hope this thread will help the Hayden users of this model as well.