Meet tbd-16

Sixteen tracks. Multiple engines per track. A deep step sequencer, mixer, effects, and a built-in browser editor — all in a 110 × 110 × 25 mm box that fits in a backpack and rivals far larger grooveboxes in what it can do.

Plug in USB-C power, connect speakers or headphones, and start making music. No computer, no companion software, no setup.

Built to be played

Four high-quality endless encoders, 30 tactile buttons with RGB feedback, a 2.4″ OLED display, and a dedicated volume wheel. Anodized aluminum top, powder-coated steel base.

USB-C powered, with a power-bank mount on the underside — pick whatever battery capacity you need, or leave it off and travel with tbd-16 in hold luggage.

Three dedicated processors keep audio rock-solid: an ESP32-P4 for DSP, an RP2350B for UI and MIDI, and an ESP32-C6 for WiFi.

Sequence and sound

The Groovebox app comes preinstalled. Step-sequence beats or play them live, lock parameters per step, and run polyrhythmic patterns with independent track lengths. Per-track pitch, length, arpeggiator, and Euclidean generator.

Mix with effects sends through onboard delay, reverb, and a master compressor. Sync with Ableton Live over WiFi or USB. Plug a Novation Launchpad Mini MK3 or Launchkey Mini MK4 into the USB host for an extended performance surface.

Engines

Each of the 16 tracks runs a sound engine — what we call a Machine — with its own parameters and presets. Engines based on Mutable Instruments’ Plaits, Braids, and Rings sit alongside original CTAG voices like a custom FM kick, a new clap, and a 24-engine macro voice with an AHR envelope.

Drums — Synth Kick · Analog Bass Drum · FM Kick / Bass · Digital Snare · Analog Snare · Hi-Hat 1 · Hi-Hat 2 · Rimshot · Clap

Tonal — TBD03 (303-style acid) · Mono Synth · Wavetable Osc · TBDaits (24-engine macro voice) · TBDings (modal / plucked) · PolyPad

Sampler & Input — Rompler (on tracks 1–15) · External audio passthrough on track 16

The team behind tbd-16

tbd-16 is the work of a small team — built on the open-source CTAG TBD platform and shaped by people who play, design, and write code for music.

Run your own apps

Switch apps via SD card on reboot — no hacked mode, this is a default feature. A full browser-based WebUI runs over USB or WiFi, no install required, always accessible.

Run MCL (MegaCommand Live) — Justin Mammarella’s sequencer for Elektron Machinedrum, ported to tbd-16. Use the device as a standalone multi-effect processor, or as a MIDI controller and audio interface for iPhone and iPad. Or boot it into DOOM.

Tech specs

Open by design

The firmware is fully open source under GPL 3.0 — DSP, web tools, everything. Build front-end apps for the RP2350B, write DSP plugins for the ESP32-P4, or both. No tokens, no paid SDK, no proprietary account.

All Machines run on the open-source CTAG TBD platform — 50+ DSP plugins ready to go, plus your own. CTAG TBD also exists as an open-source Eurorack module, so you can take the same engine into a rack if that’s your thing.

Supported by the NLnet NGI0 Commons Fund.