by Robin Vincent | Approximate reading time: 2 Minutes
Petr Venkrbec CHRT

Petr Venkrbec CHRT  ·  Source: Sonic State Youtube


The CHRT mono synthesizer is designed by Petr Ventkbec and uses tubes to generate the meaty and truly analogue sound. The concept came about through trying to find a distinct and unique electronic sound to be played with a wind controller that would give the same sort of satisfaction as an acoustic instrument.



Designed mainly as a sound source for wind controllers such as the Yamaha WX5 or Akai EWI it can also be used as a sound module with a little bit of tinkering to the firmware. I have a feeling that many people are going to want that.

Petr calls it “Natural Synthesis” and its aim is to sound electronic but using a different approach to regular subtractive synthesis. The whole signal path is a pure thermionic valve circuit. The only digital technology is used for the MIDI-to-CV conversion and tuning.

Because it’s designed by a saxophonist there’s a big emphasis on dynamics, phrasing, articulation, accents and the crumbliest, flakiest kind of chocolate (sorry!). So like a real instrument it might take some time to learn how to play it.

Following the description in the video below the first valve acts as a sawtooth oscillator. It then runs through the next valve acting as a drive circuit. The next tube is a “brown block multi-vibrator” which acts as a resonator. And then it goes out through the final valve VCA. It’s quite a simple signal path and works very organically. You have control over the coupling of the stages and the levels going between them. Check out the video below and stick with it to pull out the meaning of things. Keep in mind it’s designed for wind controllers and so responds to tonguing and pitch bend, legato and staccato.


It’s a beautiful thing sitting within that vintage case. All those tubes, chrome and silver knobs and not a single label or piece of text. This could be something quite amazing. It can also come as a 2U rackmount unit. Someone needs to take some decent pictures because the website is truly awful and does nothing to get this product across.

CHRT is sold as a kit for €400, partially assembled for €800 or complete for €1000.

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Petr Venkrbec CHRT

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