Dual VCA solderpads and hacks



The Dual VCA module has some solderpads that you can use to change some functions on it.

v1.2 – Disable the 1K output resistor

On the top side of the PCB there are 2 solder-switches near the output jacks.
By soldering a short for any of these solder-switches, you can eliminate the 1K output resistor for that jack.
The OP’s used for this module is TL074 that has built in short-circuit protection on the outputs.
Therefore, it is possible to do this hack if you need, but it is still better to leave the 1K resistors in place for extra protection.

  • SJ3 – upper VCA A
  • SJ4 – lower VCA B

v1.2 – Disable the input capacitors

It is also possible to disable the input capacitors.
By soldering a short for any of these solder-switches, you can eliminate the 470nF input capacitor for that VCA.
It is recommended to keep the capacitors in place.

  • SJ1 – upper VCA A
  • SJ2 – lower VCA B

v1.2 – Exchange the CV1-jack with a potentiometer

The base version of the VCA has two cv-inputs that are mixed together.
If you want to adjust the bias of the cv-level, you need to have an external module with a voltage output that you connect to one of the two cv inputs.
It is possible to swap the upper cv jack, for both VCA’s, to a 100k 9mm potentiometer instead.
Follow these instructions to make the modification.