Figure 17 Schematic of IC based Parametric Equalizer. The input goes to one end of a 10 k ohm resistor. The other end goes to the inverting input of an op amp. There is another 10 k ohm resistor connected between the inverting input and the output of the op amp. The input also goes to the counter clockwise end of the presents control, 4.7 k ohm. The clockwise end of this control goes to the output of the op amp. The wiper goes through a 0.015 u f capacitor then a 1.8 k ohm resistor to one end of a 180 k ohm pot connected as a rheostat. This is one of a dual ganged pot which is the frequency control. The other end of the first rheostat connects to the second rheostat which is part of the frequency control. The other end of the second rheostat goes through another 1.8 k ohm resistor to ground. The junction of the two rheostats connects through a 0.01 u f capacitor to ground. The junction also connects through a 100 u f capacitor to the noninverting input of the op amp. The noninverting input goes to ground through a 680 k ohm resistor. There is another 680 k ohm resistor connected from the junction of the two rheostats to the junction of the 0.015 u f capacitor and the 1.8 k ohm resistor.
End of verbal description.
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