- 4 x EOC (end of cycle) pulse outputs corresponding to the 4 function generators.
- voltage control of attack and decay (with attenuators) of all four envelopes
- 2 x analog or (aka peak circuit) logic outputs that are normalled to the two pairs of envelopes (1+2 and 3+4) with attenuators.
- special quadrature modes for envelopes 1+2 and 3+4.
- connects to the quadra via 4 ribbon cables
- 12hp and skiff friendly