Built inside a jar, this synthesizer has a square-wave oscillator as well as sweeping LFO modulation effect. The pitch and speed are controlled by outside light sources hitting the two light sensors inside so there is a lot of room for experimenting.
All of the components are built in a three dimensional floating circuit that comes down from the lid of the jar.
A yellow LED pulsates in time. There is a single switch on top for power which is supplied by 9v battery, and a 1/4″ audio output jack.
This was built in a series of six.