GZD - audio frequency to control voltage

modular synths menu

what is it

This software attempts to find the frequency with the biggest magnitude in an audio-signal. This frequency is then transformed into a control voltage.

The sampling is performed 100x/second so that's the number of notes played per second it can recognize.

It won't work with e.g. a regular musical track of your favorite artist, it is meant for a single instrument.

magnitude? control voltage?

The GZD contraption is meant for eurorack modular synthesizers (Doepfer A100 compatible).



The MCP4725 needs to be connected to the I2C pins of the raspberry pi. The VCC to the 5V (should work: the raspberry is the I2C master but if you don't feel safe, use a level shifter). Connect a mono jack 3.5mm socket to the GND/OUT pins of the MCP4725.


The software can be found on GitHub.