e-coltranius #1: VCV Rack with Breath Control

My first EWI exploration with VCV Rack, an Open-source virtual modular synthesizer. As VCV Rack approaches version 1.0, things are getting interesting, and the upcoming stability is getting me excited about the sound possibilities for EWI!

All modules used in this video are free, and they are POWERFUL. Wrapping my head around the work flow for designing a dynamic, expressive synth voice with breath control has been less formidable than I thought. One of the custom modules (Dual MIDI to CV) makes it easy with dedicated CC #02 routing! Of course, a much simpler voice could be made with a simple oscillator, a low pass filter, a VCA and an ADSR filter. Routing CV gates and breath through a multiplier to trigger/control everything, and a slew-rate limiter/inverter to smooth the translation of MIDI to control voltage should go in the category of "minimum" needs, too.

Now, for some short educational programming...

When I first started using a breath controller I was very much in the dark about how breath control worked. It took reverse engineering several patches made by other people to figure out the basics. In its most basic form, you are modulating some parameter (usually volume or the cutoff frequency of a low pass filter) with data from your breath sensor. Note data is pretty straight forward: your controller says "start playing C4 now, and stop playing now."

Now, to turn the electronic sounds into something more organic we need to smoothly adjust a parameter and cause a change in perceived loudness. This change can be achieved by gradually increasing the amplifier volume as you blow harder, but if you want to create a sound with more "living" characteristics you can instead gradually increase the cutoff frequency on a low pass filter from 0 (completely closed, and there for blocking all frequencies). As the filter opens, more harmonics are allowed through, causing the perceived sound to get louder AND brighter. I have heard this setup (breath sensor routed to a closed low pass filter cutoff frequency parameter) on a pure saw wave called the "heart and soul of wind synthesis."

If you experiment with Eurorack (or any other kind of synthesis) and breath control, let me know - I love this stuff! - BD