This is a light controlled square-wave generator with a pulsing effect, hand built into an Atari paddle controller. These were originally built by Gemini for the Atari system. Pitch is controlled by a light sensor, speed is controlled by the knob, and the trigger is power. At high speeds you can get some interesting throaty sounds. For more precise control and wider pitch range experiment with different light sources.
A red LED pulses with the sound. It can easily be connect to amps, effects, recording equipment, etc. At the end of the original cord is a 1/4″ plug and running from there is a wall adapter for power.
Four of these were made now two have a home as a part of Night Toilet’s rig. Here is a video of them performing at Clocktower Gallery in New York.