Available as an assembled Module and as a DIY project.
This Module is currently available.
2HP lo-fi transistor VCA
lo-fi transistor VCA of the type found in old-skool Roland drum machines such as the 808. If you want super high-fidelity sound reproduction then this most definitely isn't for you. On the other hand, if you want something a bit dirty which performs really well with percussive sounds, as befits its origins in a drum machine, then this will have you covered.
https://www.etsy.com/listing/688637120/tvca-2hp-lo-fi-transistor-vca-for?ref=shop_home_active_52