This module is a VCA that uses rectified feedback/feedforward to provide waveshaping. Both the feedback/forward knobs can provide positive or negative feedback and the external CV control is an attenuverter. It also includes switchable Zener diode limiters to soften the output when large amounts of positive feedback are used. The module is DC coupled, so it can be used with LFOs, Envelopes and CV sources as well waveforms. The DC coupling also allows for DC offset to be applied to the input which increases harmonic possibilities.
This module is designed for 12V systems, but works with 15V systems with just one resistor change. The documentation gives tips on how to tweak or modify the circuit.
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.
