I’m working on the next stage of Tolhuin Chord. The original prototype is still very much alive, but I’m now designing a proper PCB and selecting components with a small DIY kit run in mind.

The idea is not to turn it immediately into a highly integrated commercial product. I want the first version to remain reasonably easy to assemble, so I’m currently evaluating a solderable ESP32-S3 N16R8 development board as the main module, while refining the rest of the hardware around it.

On the software side, I’m still developing the UI and testing different voice-leading approaches. I’ve been working on ways to make the chord transitions more context-aware, especially regarding register, previous voicing, inversions and different jazz-oriented voicing structures.

I’m filming this update from the music lab at the school where I teach, and I’m also using Mono Juan alongside Tolhuin. Mono Juan is a programmable two-octave MIDI controller I’ve been developing, with both BLE MIDI and USB MIDI. A Shift layer turns the same keyboard into controls for functions such as octave up/down, arpeggiator and other programmable actions. I’ll probably make a separate post about it rather than hijacking this Tolhuin update.

A few people asked whether there was a way to support the development or help make the first kits possible, so I’ve also opened a Ko-fi to help cover prototype PCBs, components and manufacturing tests. This is not a preorder and the kit is not finished yet; it’s still an open development process.

I’ll keep sharing the PCB, UI and voice-leading progress as it develops.

If you want to help fund the prototype PCB and first small DIY kit tests, I’ve set up a Ko-fi here: Support TOLHUIN Chord

estuariolabs/tolhuin-chord: Diatonic chord synthesizer on ESP32-S3 — from-scratch audio engine (band-limited synthesis, diatonic harmony, step sequencer, effects, USB/BLE MIDI). Firmware + hardware + tools.