Available as an assembled Module and as a DIY project.
This Module is currently available.
Basic Utility Function Module by rezwax
rezwax presents Rudiments. The 3 channels of attenuverting/offset are normalled to the logic section (min/mid/max), which are normalled to the rectifier section (fullwave negative, inverted, fullwave positive), which are normalled to the first input of each sum channel (A+B). The sum channel outputs cascade, so that if nothing is plugged into the output of channel 1, it is instead added to channel 2, and the same with 2 to 3.