Ljunggren Audio

Roll Your Own

Eurorack DIY

Modifications

3xVCA

 

Download assembly and calibration instructions here.

Download schematics here.

 

Normalisation (This mod is made on all assembled 3xVCA)

To get linear slope on the first out, exponential slope on the second out and more exponential slope on the third out simultaniusly while only patching a signal to the first in and cv to the first cv in. You need to solder some wire behind the jacks to make them normaled via the switches inside the jacks. It is advisable to use insulated wire or cover them with shrinktube.

 

 

Version 1.0

 

 

 

 

 

 

 

 

 

The modifications in place on the PCB with jacks can be seen in the picture above.

Connect the signal pin on the first CV input to the switch pin on the second CV input.

Connect the signal pin on the second CV input to the switch pin on the third CV input.

Connect the signal pin on the first OUT to the switch pin on the second IN.

Connect the signal pin on the second OUT to the switch pin on the third IN.

 

 

Version 1.2

 

 

 

 

 

 

 

 

 

 

 

 

In version 1.2 solder pads have been added to make this modification easier. You can now use component pins that you have cut off from the components after soldering. Four jumpers is needed as indicated in the picture above. No shrink tube or other isolation is needed as long as you place the jumpers on the same side as the jacks.