After a few days of fiddling around with spare parts, Plunkett succeeded in designing a circuit that could change the frequency of notes by simply rotating a potentiometer. Then, something unexpected happened:
“I went next door, and asked a friend of mine to plug a guitar into this pile of wires, resistors, and capacitors I had on the bench. He strummed a few chords while I turned the knob on the potentiometer. It went ‘WAH-WAH-WAH.’ We looked at each other, and said, ‘Wow! This is really great!’”
And it looks like this :
Abnormal Capitalist 