Add 2

Precision adder and averager in 2 HP. Each of its two sections sums three inputs to one output at exact unity gain, so pitch control voltages add up without the error a mixer's gain controls bring. A jumper on the rear turns a section into an averager, to combine LFOs or audio sources without raising their level or clipping. With the bottom section's first input unpatched, the top output is fed into the bottom section, so five signals combine into two outputs. High-end components make it as suitable for audio as for control voltages and gates.