| midi-in | MIDI input circuit |
| midi-out | MIDI output circuit |
| midi-y | Breakout circuit for MIDI and Power on a single wire |
| buffer | Impedance buffer OP Amp |
| dualsupply | Dual power supply circuit |
| mixer | Mixer op-amp |
| negamp | Negative-gain op-amp |
| posamp | Positive-gain op-amp |
| piezo | Conditioning circuit for piezo sensors |