Main Content

Many modular synthesizer systems use Control Voltages (CV) to pass note information from one module to the other. When I started building my first modular VCO, I didn’t have a keyboard/sequencer capable of outputting CV signals, so I cooked up this project that uses a Seeduino Xiao microcontroller and a handful of parts to make a fairly respectable CV sequencer.

The code and schematics can be downloaded from my github.

DISCLAIMER: Use at your own risk! In other words, before you hook this up to your fancy modular system or analog system, test it out on a multimeter, test equipment, junky module or whatever you’re not worried about in case you get the magic smoke. I’ve tested it on a couple of my DIY oscillator modules and nothing has blown up. But do your due diligence and test it carefully before you roll it out as part of a larger system.

Simple Version:

1x Seeeduino Xiao microcontroller
1x 3.5mm mono audio jack (or ¼” audio jack if you prefer)
For Full Version Add:

1x additional 3.5mm mono audio jack (or ¼” mono audio jack if you prefer)
1x rotary encoder 1x 10 potentiometer (linear taper)
4x LEDs 4x 100 ohm resistors 1x SPDT (ON-ON) switch
For Modular Panel Version Add:

1x Schottkey Diode
1x Transzorb (TVS) Diode
1x 10uF ceramic capacitor
1x SPST (ON-OFF) switch
1x USB panel mount cable (optional)”

Link to article