This is a strange machine. It's used to reanimate dead circuit-boards. It's a simple oscillator that's designed so that part of the circuit is left incomplete. You take any old random circuit-board and connect it to this box using the attached wires. The components in the mystery board become part of the oscillator circuit and complete it, causing sound to come out. So depending on the particular board you're using, and where you attach the wires, you'll get different pitches and timbres.
The front of the box also has a contact-mic glued onto it which you can push to change the sound. When you push it hard it causes the sound to distort and this makes the lights on the Bros's heads light up.
This is a paper circuit-board design from ciat-lonbarde.net. It runs off 9 volts so it's safely touch-sensitive. You can use your skin in between the connecting wires and the dead board, which gives you touch sensitive control of pitch. This is particularly effective when touching the contact-mic sensor at the same time.
Powered by 9V battery or 9V DC centre-negative power supply.
Circuit: Ciat Lonbarde Blackgroundcorn. Built by Pat Kraus.
What is an Oscillator?