Active tone control with op amps. In part A, on the left the lower input terminal is grounded. The upper input terminal connects to one end of R1. The other end of R1 is connected to the inverting input of the amplifier which is represented by a triangle. The noninverting input of the amp is grounded. One end of R2 also connects to the inverting input and the other end of R2 goes to the amp output. The amp output goes to the upper output terminal and the lower output terminal is grounded. In part B the lower input terminal is grounded. The upper input terminal goes through an 11 k ohm resistor to one end of the bass pot, 50 k ohm linear. The other end of the bass pot goes through another 11 k ohm res to the output of a different amplifier. There is a 0.1 mike cap connected from the wiper to one end of the pot. There is another 0.1 mike cap connected from the wiper to the other end of the pot. The wiper of the pot connects through a 15 k ohm res to the inverting input of the amp. The noninverting input is grounded. The upper input terminal also connects to one side of the treble pot, 50 k ohm linear. The other end of this pot connects to the amp output. The wiper of the pot connects through a 6.8 k ohm res then through a 0.001 mike cap, in series, to the inverting input of the amp. The output of the amp connects to the upper output terminal and the lower terminal is grounded. End verbal description.
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