556 timer based oscillator with lfo.
This one is build upon a 556 timer oscillator also known as
atari punk console (god only knows why it's called that way). Thanks to the excellent
Nicolas Collins' book
Handmade Electronic Music I played with couple led-photoresistor to get a kind of rate-controllable lfo.
There's also two photoresistors which can be triggered independently. Very nice techno-like bass line. It's build in a red plastic 고추장 box.