Hi, I'm reverse engineering an old Fender 5D8 Twin. I'm hoping to build a similar amp, with some mods to enhance efficiency. Here's the stock circuit: http://www.ampwares.com/ffg/schem/twin_5d8_schem.gif http://www.ampwares.com/ffg/schem/twin_5d8_layout.gif Since both low gain inputs are pretty much useless, I would love to omit them. In doing so, I can eliminate one whole 12AY7 and its corresponding circuitry (plate resistors, etc). With such a modification, would I need to change any component values to maintain spec voltages and biases throughout? If so, please explain why. How are the proper values calculated? Any tips, info, pointers, and/or educational references would be greatly appreciated. Thank You!