Available as an assembled Module and as a DIY project.
This Module is currently available.
FOUR CHANNEL SCANNING VCA
HollaSynth Four Channel Scanning VCA adapted (by Low-Gain) w/ permission to fit Low-Gain Electronics aesthetics.
Panel's may or may not become available at SynthCube.
But PCB's are available at SynthCube! Pre-Assembled Modules can be obtain via Low-Gain Electronics Contact Page.
** 4U Modular is a term used for the format most commonly known as “Serge Format” or “Loudest Warning Format”. Out of respect for the ever growing format, 4U Modular is the easiest way to refer to it. More Specifically it refers to the panel height and mounting hole style. 4U Modular will patch up just fine with other 4U "Serge" formats such as "Random Source", but it will not mount in RS boats or Buchla Boats (or power off Buchla power for that matter). An info page about this will be added to the website soon to make this a lot more easy to understand.
https://synthcube.com/cart/hollasynth-scanner?search=holla&description=true
These merchants probably sell this module. Huh?