Funk (Twang) Guitar Effect Box Circuit

 

This is an audio effect circuit that give extra oscillation to your guitar, percussive, or semi percussive instruments, you can call it a funk box. This guitar effect circuit is basically a damped oscillator that is set slightly below its critical oscillation point. This is the figure of the schematic circuit;

The oscillator part is constructed by feeding back the output signal through a band pass circuit, with the center frequency is adjusted by potentiometer R7 to add an extra “twang” , adjustable from low to high pitched timbre. Potentiometer R4 is used to adjust the gain of the oscillators, should be set to damp the oscillation at the desired decay time.  To adjust it, turn the knob slowly until a steady oscillation occurs, and turn back slightly just before it happens (the oscillation should ceases slowly).