Found Motive

custom firmware kit for the OP-XY, OS 1.2.0 / kit 020

Custom Firmware OP-XY
Twelve Machines.

A recorded Martin HD28 that strums in time, a wooden choir, a shaker, a piano, a groove kit, an upright bass, a granular cloud and more. Built in the browser with the community open-xy SDK. Unofficial and not affiliated with Teenage Engineering.

hear them download kit 028b

machines

All audio below was rendered offline from the machines' own C++ source on a computer, at 44.1 kHz, then peak-normalized. A short fade stands in for the OP-XY amp release. Since kit 019 every machine except Phase plays louder at base level and ends in a soft limiter that never passes -1 dBFS.

01 / synth / engine 48

Guitar

The flagship. Every string is a real recorded note of a Martin HD28 (CC0, Jeff Learman), tuned to within a cent. Pick a Key and Mode and each keyboard key plays the chord of that scale degree, strummed or picked in a pattern locked to the tempo. Chord changes switch cleanly at the next step of the pattern, with no restart, gap or double strike, and the pattern stays in time from 60 to 300 BPM. Let go and the strings damp in about 0.1 s. The keyboard octave picks the register: low and dark with the bass, the middle voicing, or a bright upper-neck 4-string voicing.

Controls Page 1: Key, Mode, Pattern, Human. Page 2 (press a knob): Touch, Room, Tape, Strum.

Legato chord changes at 120 BPM: each new chord lands on the next pattern step
Travis picking at 180 BPM

02 / synth / engine 43

Choir

Eight wooden singers, bass to soprano. Each note goes to the free singer whose range suits it, so a chord spreads across the choir. Original glottal pulse and formant DSP, made out of admiration for TE's Choir; no TE code or samples.

Controls Page 1: Vibrato, Conson, Vowel, Space. Page 2: Fill, Vary, Human, Level.

Four chords, default voice

Illustration of the screen motion.

03 / synth / engine 39

Shaker

Hold a key and it shakes: each key plays its own tempo-locked pattern for as long as you hold it. Physically informed beads after Perry Cook's PhISEM, with forward and back strokes that never repeat exactly. Since kit 020 the beads are finer and smoother, with less grain, less high-frequency ring and a gentle built-in top roll-off. New Softegg preset: fine sand in an egg, moved gently, inspired by soft folk shakers.

Controls Page 1: Tone, Swing, Human, Vary. Page 2: Material (egg, tube, soft, cabasa, seeds), Grain, Stroke, Level.

One held key, egg material (default preset)
Softegg preset, 16ths at 85 BPM
C maj 7th

Illustration; this machine uses the stock page on the device.

04 / player / note player

Scale Chord

A note player in front of any instrument. Choose a key, a scale and a variation, and each key you press sounds the matching chord of the scale. Unchanged since kit 018.

Controls Key, Mode (scale, chord, off), Scale, Var (triad, drop, 7th, sus2, sus4, low 3rd, add9).

C major 7ths from single keys C, A, D, G, played by Piano

05 / synth / engine 38

Piano

A sample-free modal piano: six stretched partials on two slightly detuned strings, a lingering aftersound and a filtered hammer.

Controls Tone, Decay, Chorus, Level.

Chords and a top line

06 / synth / drum machine

Groove Kit

Hold a key for a full drum groove from real CC0 Virtuosity Drums hits: hip hop, alt, R&B, rock, reggaeton, latin, funk, plus one-shot kits. Parts mutes kick, snare, hats or percussion.

Controls Page 1: Style, Parts, Feel, Human. Page 2: Tone, Punch, Grit, Room.

Hip hop groove, one held key

07 / synth / Karplus-Strong

Upright Bass

A woody plucked upright, no samples: a finger pluck into a damped string loop, with slides and dead-note thumps. Play mode is chromatic; major and minor modes give every key its own tempo-locked bass line.

Controls Page 1: Tone, Pluck, Slide, Level. Page 2: Mode, Key, Feel, Decay.

Pattern mode, C major

Illustration; this machine uses the stock page on the device.

08 / sample / sample engine 42

Cloud Pad

A granular sampler on the drum sampler page. Up to sixteen Hann-windowed grains read the sample near a moving playhead. Spray scatters position, pitch and stereo; Shimmer layers octaves; Freeze holds a moment as a cloud.

Controls Encoders set pitch, position, size, density, spray, shimmer and freeze, per pad.

A guitar take turned into a held C major cloud

09 / synth / engine 37

Phase

A mono phase-distortion oscillator. Zero Drive is a pure sine; Drive slides the phase corner toward Bend; Color adds a second harmonic.

Controls Drive, Bend, Level, Color.

A short melody

Illustration; this machine uses the stock page on the device.

10 / effect / send effect

Tape

Wow, flutter, gentle drive, level-following dust and a tone roll-off. Only Drive saturates, so a little is a little warmth.

Controls Wow, Flutter, Drive, Dust, Tone, Dry.

The piano demo through Tape (wet return)

Illustration; this machine uses the stock page on the device.

11 / effect / send effect

Tape Loop

A tempo-locked repeat: an 8-step pattern decides when the last Size of audio latches and loops, like the OP-XY tape repeat, built as a send effect.

Controls Size, Pattern, Decay, Level, Dry.

The groove through Tape Loop, 1:8 size, alt pattern

Illustration; this machine uses the stock page on the device.

12 / sample / sample engine 40

Vocal Tune

Snaps a recorded pad to a key and scale, shifts formant, and can add one or two backing voices. A recorded-pad effect, not live auto-tune.

Controls Knob 1 pitch (shift: reverse). Knob 2 start (shift: key, press strength). Knob 3 end (shift: scale, press harmony). Knob 4 play mode (shift: volume, press formant).

Placeholder demo: a sung line, dry, then through Vocal Tune (D major, Hard). A better vocal demo is coming.

changes

kit 020

  • Shaker: smoother and less grainy, with less high-frequency resonance and a gentle built-in top roll-off.
  • Shaker: new Soft material and Softegg preset, fine sand in an egg, moved gently, inspired by soft folk shakers. Synthesized, no samples.
  • Shaker: Material now has 5 options: egg, tube, soft, cabasa, seeds. Saved presets keep their material.

kit 019

  • The original Choir animation (singers) is back.
  • Every machine except Phase is louder at base level, with a soft limiter that never passes -1 dBFS.
  • Guitar: release now damps in about 0.1 s.
  • Guitar: chord changes switch cleanly at the next pattern step, with no restart, gap or double strike.
  • Guitar: stays in time from 60 to 300 BPM.

Machine numbers, controls and layout are the same as kit 018, so existing projects keep working.

install

download opxy-kit-028b.zip sha256 file

SHA256 8e8445ecdce502adccc09e5128d7d6d8cc0502d4e6fc13ded9a4723e53dcd972

The kit: README, layout.json, offline opxy-builder.html, SHA256SUMS. It holds no firmware; you supply your own stock os.ldr.

  1. You need an OP-XY on OS 1.2.0 and a desktop Chrome, Edge or Opera (Web MIDI and WebUSB).
  2. Unzip the kit and open opxy-builder.html. It runs offline; firmware never leaves your browser.
  3. Get your own stock os.ldr: hold COM while switching the OP-XY on to open te-boot, choose the dev menu, then file transfer, and copy /upgrade/firmware/blackfin/bin/os.ldr. Keep a backup copy.
  4. Load it in the builder, load the kit's layout.json so machine numbers stay the same for your projects, build, and follow the builder's install guide.

recovery

If anything goes wrong, hold COM at power on to reach te-boot; it starts before the installed OS, so it is the way back in. To restore stock, install the official OS 1.2.0 update from Teenage Engineering, or copy your backed-up stock os.ldr back to the device root. Custom firmware is at your own risk. Back up your projects first.

credits

  • Built on open-xy by etcetc000 and the Open-XY contributors (MIT).
  • Animated screen ideas inspired by Max Mockett's OP-XY work (MIT).
  • Guitar samples: Martin HD28 by Jeff Learman, Discord SFZ GM Bank, CC0 1.0. license
  • Groove Kit samples: Virtuosity Drums by Versilian Studios LLC and Karoryfer Lecolds, CC0 1.0. license
  • Vocal Tune demo voice: "Twinkle Twinkle Little Star" sung by Dcoetzee, Wikimedia Commons, CC0 1.0. license
  • Shaker reference recording, used only for analysis and not shipped: "Eggshaker_Solo.ogg" by Paddy, Wikimedia Commons, CC BY-SA 4.0. Shaker after Perry R. Cook's PhISEM idea.
  • Code: MIT license.
  • Macro Osc: code by Emilie Gillet (Mutable Instruments Braids), MIT. license
  • Code in third_party/STM is from STMicroelectronics, released under its notice. notice
  • With great respect for Teenage Engineering, who made the OP-XY. This project is not affiliated with or endorsed by Teenage Engineering. OP-XY is their trademark. No stock firmware is distributed here.
  • open-xy SDK by etcetc000 (MIT). Screen ideas inspired by Max Mockett (https://mmockett.github.io/OP-XY/, MIT). Not affiliated with Teenage Engineering.
  • Licenses: open-xy MIT, Martin HD28 CC0, Virtuosity Drums CC0, Vocal Tune demo voice CC0, Braids MIT, STMicroelectronics notice, all notices in opxy-builder.html.

kit 020 / unofficial / made with care

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