“This synth is a pulse width modulated oscillator, routed through a light-controlled resonant low pass filter. The “growling” oscillator tonality is supplied via a PWM and an awesome high-resonance low pass filter. The oscillator is controlled via 2 Light dependent resistors (LDR) and gives you the ability to create amazing musical expression. The 10 “keys” give you different tones and allow you to play it like a keyboard
Also included is 2 Hex inverter drones, supplied via a 40106 IC. The 2 two adjustable drone oscillators give this synth three oscillators in total. You also have the ability to turn off the 2 hex inverter drones and just play around with the other oscillator.
I also added the ability to play the synth just with one potentiometer and the LDR’s. When combined with the echo/reverb feature you can really get some fantastic sounds from the synth.
Just watch the YouTube clip and you’ll see what I mean
Lastly, I have to give a shout out to Pete McBennett who designed this awesome circuit. Check out his YouTube channel here”