AM8140 Dual ADSR

Overview This module is a replica of the envelope generator in the Roland 100M which I first built in 2009. It contains two traditional fast ADSR envelope generators that use transistors to switch between phases. This type of ADSR was widely available in the 1970’s in analog modular and mono synths. Each envelope outputs both a positive and negative control voltage, with the maximum output level is 7.5V.

EuroRack Module: 16HP wide
User Manual:  AM8140 User Manual

Description  The AM8140 contains two identical envelope generators (one RED and one BLUE) with slide potentiometers controlling Attack, Decay, Sustain and Release. The potentiometer knobs are ARP style in BLUE and RED. The timing of the envelope generators can be individually switched using a front panel slide switch to normal (x1) and slow (x0.1), thereby giving a range of timings from 1 ms to 30 seconds. Each envelope generator can be gated on and off from:

  • The Doepfer power bus (connected to a MIDI CV module), this is common to both generators
  • Panel mounted momentary push buttons (RED and BLUE)
  • Gate 1 and 2 Input signals

Red and Blue LED indicators show when the respective gate signal is on for each ADSR.

Module Availability  The AM8140 was produced in small number is 2014 and a revised version is expected to be available in 2018.

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