Available as an assembled Module and as a DIY project.
No info about availability.
CV buffer
The RS-230 CV buffer is an electronically active version of the RS170 Multiple. However, unlike the RS170, you should not attempt to use the RS230 to combine the outputs from multiple source modules. It will not act as a mixer.
https://www.gear4music.com/us/en/Recording-and-Computers/Analogue-Systems-RS-230-CV-Buffer/21IY
These merchants probably sell this module. Huh?