moog music inc
911 ENVELOPE CONTROL VOLTAGE GENERATOR:
Generates the control voltage contours required for producing envelopes in conjunction with a voltage-controlled amplifier. Attack time, sfortzando decay time, and final decay time are all independently variable over a 10 millisecond - 10 second range.
From "Ultra-Short Form Catalog of Electronic Music Composition Instruments", R.A. Moog Company, October, 1965.