I was looking for a DIY project to work on during lockdown and thought a little passive mixer for my eurorack could be cool. I needed a way to mix the 3 voices from my STO module and maybe split the result into 2 outputs so I can send a copy of the signal off for further processing. I had a search online but couldn’t find a simple plan for what i was wanting to do. So I created this based on a few different schematics.
I built mine from spare parts that I had lying around so 2 of the potentiometers are B10K. I would recommend using A10K as the audio comes through a little louder. I managed to desolder the three 1K resistors from other unused and broken projects.
I also thought it would be a good opportunity to learn Autodesk Fusion 360 some more so decided to design my own panel that could be 3D printed. You can download an STL and 3MF file here if you would like to 3D print your own. Just ensure the height is 128mm before you print.
It was a little bit tricky to solder in some parts as I was trying to keep the back as clean as possible, the result works well and the fact it is passive means no power issues! A great simple DIY project to cut your teeth with.