The ASR envelope is a static envelope generator with loop feature
In envelope mode, it generates the same envelope shapes as a normal ADSR envelope, however, the Decay and Release rates are controlled by a single control named Release. The envelope has traditional RC charging/discharging (exponential decay) shapes, ideal for driving a linear VCA, modulating flter cutoff, etc. While it is not be the fastest envelope in the west, or in any cardinal direction for that matter, it is reasonably snappy with a 1.5ms minimum attack time. In loop mode it becomes a basic LFO with rates ranging from 3 seconds up to 170 Hz governed by the Attack and Decay settings.
https://kassu2000.blogspot.com/2018/10/asr-envelope.html
Module is available as a DIY project only.
This Module is currently available.
$7