This module is composed of two Sallen-Key low pass filters designed to be used on very low frequencies. When pitch control voltages are processed through this, it creates a portamento which then turns into vibrato. Depending on resonance control, this vibrato can die out almost immediately or go on for the duration of the note. When used with envelope generators, this module can be used to add extra "bumpiness" to an envelope signal allowing for more harmonic content. With a gate signal, the module can be used as a simple envelope generator with equal sloped attack and release.
This design can be used with +/-15V systems without modification
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 and panels are available now. Price for a 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.
