This one’s a really simple implementation of Doepfer’s CV Mixer with offset function. I added an attenuverter section at each input to let me invert the signal befre mixing.

It’s got a total of 5 channels. The first of which is normalled to +12V (can be used as negative through the attenuverter).

The PCB is SMT-based, which is how I was able to cram everything into a 4HP footprint.


Watch my demos of this on my Youtube channel!

Part 1 - Early prototype

Part 2 - First iteration of the PCB

(Coming soon!)


Clock Divider Schematic. Click for larger image.


My PCBs in this series were sponsored by PCBWay – a great option for prototyping. Use their Quick-order PCB tool to get an instant quotation on the files.

PCB shops use Gerber files for etching copper traces, printing labels, drilling holes, and other manufacturing steps. You can download my zipped Gerber files for a version you like and upload those into their website.

Make sure to print both boards!


v0.3 - LED Fix 2 (Unverified)

This should fix the opamp setup from the previous version.

Gerber FilesMiniAttenuMix v0.3 -
MiniAttenuMix v0.3 -
BOMMiniAttenuMix iBOM
v0.2 - LED Fix (DOES NOT WORK!)

Does not work. This was my first attempt at fixing the LED problem. Made a mistake at the OpAmp section for the LED.

Gerber FilesMiniAttenuMix v0.2 -
MiniAttenuMix v0.2 -
BOMMiniAttenuMix iBOM

v0.1 - Initial version (DOES NOT WORK!)

You can print this version but the LED won’t work unless you replace R19 with a 4.7k resistor from the LED’s Anode (+) to Pin 1 of U3.

Gerber FilesMiniAttenuMix v0.1 -
MiniAttenuMix v0.1 -
BOMMiniAttenuMix iBOM
Fix for MiniAttenuMix v0.1 LED


I’ll have to get v0.3 printed before I can confirm that it works, but you can print in at your own risk!

Follow my Instagram @benjiaomodular for updates.