The concept behind the morph controller is that a series of 4 overlapping triangular envelopes are generated from an input CV (plus manual offset), meaning that it can be used with a quad vca (such as the qvca) to fade across four audio sources. As it was originally thought of as a companion to the qvca, the moco also has a simple 4:1 audio mixer for recombining the four outputs, saving the use of a separate mixer module.
https://wiki.aemodular.com/pmwiki.php/AeManual/WonkyStuffMoco
ESI MoCo pass. Monitor-Controller
ESI Audiotechnik MoCo Monitor Controller
Artesia MoCo Passive Monitor Controller
ESI MoCo
ESI Moco
ESI ESI MoCo