This 14 HP wide module contains two identical voltage controlled ADSR envelope generators, with curve select, mode select and variable timing. Each stage of the ADSR, including timing, can be controlled by an external +10V control voltage. The curve can be selected from exponential or linear, and the mode of the ADSR can be selected from normal ADSR to a looping mode.
It is a re-imagining of the Dual VC Envelope Generator that Tonus announced in 1970 for the for the ARP 2500 Modular Synthesizer, but the module never made it to production, until now!
Description The AMSynths AM1037 fills in a piece of history by re-imagining the original ARP module with a modern digital circuit that is stable and accurate.
The attach, decay, sustain, release and overall time of the AM1037 can be controlled by the control knobs or external CV signals that are patched into the module. The A, D and R stage timings can be varied from 1ms to 10 seconds, and the Sustain level from 0 to 10V. The timing of the ADSR can be controlled from a 10s maximum to a 1s second maximum.
The envelopes are activated by a manual push button (red LED) and/or an external Eurorack gate signal. High quality Alpha potentiometers and Rogan ARP 2500 knobs have been used, to ensure stage times can be easily set and adjusted. The 10V outputs are compatible with the Behringer 2500 ecosystem or any Eurorack modules that accepts 10V CV’s.
Controls Each envelope generator (of two) has five variable potentiometers and three switches;
- Attack, Decay and Sustain controls
- Release and Time controls
- EXP – A button and green LED that latches the ADSR into exponential curves
- MODE – A button and blue LED that latches the ADSR into a looping mode
- MANUAL – A button red LED to activate the ADSR
Connections Each envelope generator has nine 3.5 mm jack sockets on the anodised aluminum front panel:
- Attack CV, Decay CV, Sustain CV – 0 to +10V control voltages
- Release CV, Time CV – 0 to +10V control voltage
- Gate – A CV signal above +2V will activate the envelope generator
- Trig – A CV signal above +2V will re-activate the envelope generator
- Out – 0 to +10V CV output from the envelope generator
- Inv – 0 to -10V inverted CV output from the envelope generator
The module comes with a set of M3 mounting screws and washers, and a standard 16-way Doepfer power cable.
The module was developed in the winter of 2025/25 and went into production in the Spring of 2026.
