No info about availability.
Ext. Input / Envelope Follower
a modified version to give an input to the comparator (threshold + gate out) for use with external signals, rather than just the Env Follow signal. Mod described at www.niroke.blogspot.com
These merchants probably sell this module. Huh?
Elektron Digitone 8-Voice Digital
Moog Minimoog Voyager RME Rack Mount
Korg EXB-PCM01 Piano / Classic Keyboards
NuX NSS-5 Solid Studio IR and Power Amp
Studer B67
Lorre Mill Comb Room