Ljunggren Audio

Roll Your Own

Eurorack DIY

Distortion / VCA



Download assembly manual here. (3.3MB)


A compact, easy to use, easy to build and great sounding distortion module which will also work as a VCA if desired.


The Optodist is based on two Advanced Photonix (formerly known as Silonex) optocouplers that gives its characterful overdriven sound and plucky dynamic response to CV, it is equally at home adding a bit of extra crisp to highs and mids or warming up your lows as it is turning a resonant filter into a howling beast or your drums into crushing carnage.


The Optodist comes supplied with the SR3 optocoupler but is also designed to handle the SR2 version. SR3 givies a tighter, snappier CV response and have less bleed through of the signal when gain is fully off and signal in is set to low settings for a somewhat clean signal or with a lighter distortion. Please note that due to the nature of the vactrol-style optocouplers, response behaviour may vary between different factory batches.


Also on board is an LED based limiter circuit which limits the signal thru a set of 4 LEDs which can be seen on the panel, for adding a different flavour to your distortion. Experimenting with different types will affect the sound.


The Optodist Kit is a novice-friendly project, it is a low part count, single-PCB build that only requires the most basic experience in PCB soldering and module assembly. Kits comes supplied with PCB, front panel (PCB material), component kit, knobs, power cable and mounting screws. Solder and tools are not supplied.


Grayscale panels as long as stock lasts: @Grayscale @synthCube



Download assembly manual here. (3.3MB)

Modifications to Optodist can be found here.


Basic specifications

Width: 6hp

Depth with power cable attached: Less than 35 mm.

Power: +/- 15 mA


* Regarding our PCB/panel only offerings, please note that these are mainly offered due to popular demand from the experienced DIY community. Hence we are counting on that you know what you are doing and how to source parts. If you feel the least bit uncertain, please consider going for the kit.