142 Dual Envelope Generator

Description

This module is a replica of the System 700 Dual ADSR from 1976. The circuit uses a unijunction transistor to provide fast envelopes and both Gate and Trigger inputs.

The envelope shapes have been accurately translated into Eurorack, along with the dual timing feature (x1.0 and x0.1) and normal and inverted outputs (at 0V to

±10V).

Both ADSR’s can be manually gated on from the front panel or set to respond to just Gate signals or both Gate and Trigger signals. The Trigger signal re-triggers the envelope even when the Gate signal is on, enabling fast keyboard runs to be easily played. 

A MIDI interface with Gate and Trigger, such as the Intellijel uMIDI is recommened, or an orignaal Roland 100M keyboard.