This module is a voltage controlled Sallen-Key filter. The low-pass and high-pass inputs can be used simultaniously and it is capable of self-oscillation.
This is all analog, and only requires one resistor change between 12V and 15V systems.
For complete descriptions of the way the module is used, and how to build it, including schematics and parts list; download this PDF file.
Boards are available now. Price for 1 PCB is $8.
Unfinished eurorack
panels are available for this project, they are 6HP and cost $8 each.
There is
more information here about panels. If you're interested in drilling your own panel for
this project, feel free to use my
drill guide. That image should be printed at 300dpi for proper
scaling.
