The A-140 is an ADSR envelope generator and outputs an envelope when a gate input is applied. This varying voltage is output in normal (positive) and inverted (negative) form, and can be used for control modulation of a VCO, VCF, VCA or any other control voltage destination.
The shape of the envelope is governed by the four parameters Attack, Decay, Sustain and Release. The envelope is started (triggered) by a gate signal either from the INT GATE voltage on the system bus or if a signal is connected to the Gate input socket. The envelope can be re-triggered each time a trigger signal is sensed at the Retrig input socket when the gate is still open.