Active tone control with a triode. The lower input terminal is grounded. The upper input terminal goes through a 470 k ohm resistor to ground. The upper input terminal also goes through a 110 k ohm resistor to one end of the bass pot, 500 k ohm linear. The other end of the bass pot goes through another 110 k ohm res to the output terminal. There is a 0.01 mike cap connected from the wiper to one end of the pot. There is another 0.01 mike cap connected from the wiper to the other end of the pot. The wiper of the pot connects through a 150 k ohm res to the grid of a triode, 12 A X 7. The upper input terminal also connects to one side of the treble pot, 500 k ohm linear. The other end of this pot connects to the output. The wiper of the pot connects through a 68 k ohm res then through a 100 pf cap, in series, to the grid of the triode. The output terminal connects through a 0.47 microfarad capacitor to the plate of the triode. The triode plate also goes through a 100 k ohm resistor to B plus. The cathode of the triode goes through a 1.8 k ohm resistor to ground. There is a 100 microfarad cap in parallel with the 1.8 k resistor. End verbal description.
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