Benjamin Poilve's minichord Is a Pocket-Sized Teensy 4.0-Powered Subtractive Synth

Engineer, designer, and maker Benjamin Poilve is working with Seeed Studio to bring his compact musical gadget to life: the open-hardware minichord, a pocket-friendly subtractive synth designed for building chord progressions.

"The minichord is a pocket-sized instrument designed to build interesting chord progressions," a video introducing the project explains. "Basic chords are easily selected by choosing single buttons; more complex chords can be built by selecting multiple buttons. The sensing bar is precise and reactive, allowing the use of strums as well as arpeggios."

Inside the minichord's compact housing is a Teensy 4.0 microcontroller, connected to 21 main chord buttons in a 7×3 keypad and a "sharp" button, plus a 12-section "harp touch zone" sensing bar. Two further buttons provide access to presets, and three potentiometers adjust volume of the chord and harp with the third customized depending on the particular preset chosen. Finally, a "rhythm mode button" toggles between discrete and continuous chord playback modes.

The minichord isn't just a simple soundboard, though: Poilve says the gadget includes a "fully-fledged subtractive synthesis engine," presets for which can be accessed using a web interface accessible over a USB connection. Presets can be shared with other users, and loaded into the device's 12-bank internal memory.

Poilve has successfully built minichords, and has released the design files and source code under the Creative Commons Attribution-NonCommercial 4.0 International and BSD three-clause licenses respectively — but is now looking to take the project to production, partnering with Seeed Studio to enter it into a competition to be built for sale on the Seeed Bazaar store. "At the end of each month, we'll count the likes [on the entry videos]," Seeed explains, "and the top three projects will have a chance to be brought to life!"

More information is available on the minichord website, with the source code and design files available on GitHub; those wanting to vote for the gadget to win Seeed's competition should visit the company's YouTube video and click "like" for their vote to be counted.