Here’s a utility module that lets me control my analog synth with a MIDI controller. It’s based on Elkayem’s design on Github.
V/Oct or Note
Standard volt-per-octave output used by Eurorack synths. It has a total range of 88-keys (+7 volts).
0-5V output based on the velocity parameter sent through MIDI. Usually controlled by how hard a key is pressed on a MIDI controller.
5V whenever at least one key is active/held down. 0V if no key is being pressed.
Short 5V pulse whenever a new key is pressed, regardless of how long is held down.
Standard clock pulse based on the BPM set by the MIDI controller.
Pitch and Ctrl/Control
CV outputs based on the wheel controls on a MIDI controller.
This MIDI2CV module is meant to be used for mono synths. The Note Priority toggle on the side selects which note to send out of the v/oct output whenever multiple keys are pressed.
Set it to HIGH to chose the highest note being pressed, LOW to chose the lowest, and LAST to always prioritize the latest note that was pushed down.
I have tested this circuit both on +9V as a pedal an on +12V with my modular synth system.
Some additonal features such as MIDI channel selection and polyphone can probably be explored in the future.
Let me know if you’ve built it. Tag me on Instagram @benjiaomodular.