“This is my 2nd version of the fizzle loop synth and this time I use 4 x 555 times (yes you heard me right!)
Its circuit is really just 2 flashing LED circuits and also a light Theremin circuit mashed together. Ive added a potentiometer to each LED to be able to dim it along with the ability to change capacitor and resistor values via switches. This gives you the ability to change the sound, tone and speed of the synth making for a much more varied sound machine then the first Fizzle Loop synth.
I also used 2 vactrols (check out step 3 on what these are if you havent heard of them before) which connect the flashing LEDs circuits to the light Theremin circuit.
After a bit of experimenting I found that the values on the resistors and caps I choose gave me a good range of sound. I strongly encourage you if you do make one of these, to do your own experimentation to find what works best for you.
Check out the video of the synth in action”