A circuit which generates a signal, usually meant to control a voltage controlled amplifier for the purpose of giving dynamic contour to a played note (in order words, providing a rise and fall of the volume of the note). Envelope generators have come in many forms over the years, but the simplest and the perennial favorite is the ADSR envelope generator. ADSR is an acronym for «Attack, Decay, Sustain, Release», the four segments of the ADSR generator's output.
ASR Generator with siplified logic portion of the circuit by combining Decay and Release into a single control
The simplest solution for creating an ADSR /LFO generator based on a single LM324
Modified version of Yves Usson's Yusynth ADSR envelope generator by Caspar Ockeloen-Korppi
Генератор огибающей на дискретных компонентах