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Keith McMillen Instruments QuNexus — ultra-portable 25-key USB MIDI keyboard with pressure, tilt, bend pad, and patchable CV/expression on Linux
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| name | qunexus |
| description | Keith McMillen Instruments QuNexus — ultra-portable 25-key USB MIDI keyboard with pressure, tilt, bend pad, and patchable CV/expression on Linux |
| category | instruments |
Keith McMillen QuNexus is a 25-key ultra-portable USB MIDI keyboard with polyphonic aftertouch (pressure), tilt (x/y bend), and patchable CV/expression inputs.
| Spec | Detail |
|---|---|
| Keys | 25 keys (one octave each for C–B, across 2 octaves) |
| Sensors | Pressure (per key), X-tilt, Y-tilt |
| Bend | Touch-sensitive bend pad (horizontal) |
| Inputs | Dual expression (1/4" TRS), CV (1/8" TS) |
| MIDI | USB MIDI, 5-pin DIN (with KMI MIDI Expander) |
| Presets | Multiple configurable presets |
| Power | USB bus powered |
Each key reports polyphonic aftertouch (MIDI Channel Pressure / CP).
Horizontal touch strip above keys: up/down pitch bend. Assignable to CC.
Keys report X (left/right tilt) and Y (front/back tilt) per key.
CV IN — 1/8" TS, accepts +/-10V or 0-5V (switchable)EXPR 1, EXPR 2 — 1/4" TRS expression pedalsPress SHIFT + [0-9] to select preset slots 0-9. Factory presets store common configurations.
Hold SHIFT + MODE to enter CoMA. The QuNexus learns any MIDI mapping from connected software.
Editable via QuNexus Editor software (Mac/Windows/Linux via Wine).
# QuNexus USB MIDI on Linux
amidi -l # find QuNexus port
# QuNexus MIDI channel: per-preset (default=1)
| Message | Data |
|---|---|
| Note On/Off | Standard 0x90/0x80 |
| Channel Pressure | Per-key pressure (0-127) |
| Pitchbend | Bend pad (14-bit, ~0-16383) |
| CC | X-tilt, Y-tilt, expression 1/2 |
| Control | CC |
|---|---|
| X-tilt | 74 (default) |
| Y-tilt | 1 (modwheel) |
| Expression 1 | 7 (volume) |
| Expression 2 | 11 (expression) |
| CV In | 20 |
# QuNexus uses standard USB MIDI class driver
# No special driver needed — appears as USB MIDI device
# Route MIDI
aconnect -i | grep QuNexus
aconnect 128:0 24:0 # to your synth
# Monitor
amidi -p hw:X -d # raw MIDI dump
CV input requires the KMI CV Cable Kit or similar to convert +/-10V CV to 0-5V for the QuNexus.
The QuNexus and QuNeo are both KMI products and share:
Unlike the QuNeo, the QuNexus does NOT have SysEx for preset upload — presets are stored on-device via the editor.
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