“This is an original 1976 (23 Aug 1976 shown on the label) Moog 912 Envelope Follower module. It was taken out of a full Moog Modular system back in 1993 when I rebuilt a musician’s Moog modular system into a new large cabinet. This was the module that he decided to remove to make space for a different module. As far as I know the 912 was fully working when it was removed and I currently have no way to test it.
The original Moog S Trigger socket was changed at some point to a standard 1/4″ jack socket, which is how the later versions of this module were built. ” Click here to visit listing on eBay