Available as an assembled Module and as a DIY project.
This Module is currently available.
Stereo Mixer
Panel / module for CGS 506 Stereo Mixer in LW format
http://www.loudestwarning.co.uk/portfolio/cgs506-serge-multi-channel-stereo-mixer-mcsm/
https://www.elby-designs.com/webtek/cgs/serge/cgs506/cgs506.htm
These merchants probably sell this module. Huh?
