I am looking for a schematic for a Automatic Volume Control circuit that i can hook the audio output from the computer to a color organ circuit. Iwant to do this so as i change the volume the lighting effect doesn't change!
This is the European symbol for a variable tapped resistor. This changes the gain of the operational amplifier circuit. Another symbol would be a zig zag line for the resistive portion and an arrow touching the zig zag for the variable tap.
For circuits like this you can use the popular LM358 dual-opamp, or other option will be LM324 (quad) and then you will replace all 3 opamps with this one.
Regards,
IanP