qunexus

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

QuNexus Skill

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.

Device Overview

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

Key Features

Pressure-Sensitive Keys

Each key reports polyphonic aftertouch (MIDI Channel Pressure / CP).

Bend Pad

Horizontal touch strip above keys: up/down pitch bend. Assignable to CC.

Tilt / X-Y

Keys report X (left/right tilt) and Y (front/back tilt) per key.

CV/Expression Inputs

• CV IN — 1/8" TS, accepts +/-10V or 0-5V (switchable)
• EXPR 1, EXPR 2 — 1/4" TRS expression pedals

Modes

Preset Mode

Press SHIFT + [0-9] to select preset slots 0-9. Factory presets store common configurations.

CoMA Mode (Controller Mapping)

Hold SHIFT + MODE to enter CoMA. The QuNexus learns any MIDI mapping from connected software.

Live Edit Mode

Editable via QuNexus Editor software (Mac/Windows/Linux via Wine).

MIDI Implementation

# QuNexus USB MIDI on Linux
amidi -l  # find QuNexus port

# QuNexus MIDI channel: per-preset (default=1)

Typical MIDI Messages

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

Mapping (Factory Defaults)

Control	CC
X-tilt	74 (default)
Y-tilt	1 (modwheel)
Expression 1	7 (volume)
Expression 2	11 (expression)
CV In	20

Linux Integration

# 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 Conversion (requires hardware)

CV input requires the KMI CV Cable Kit or similar to convert +/-10V CV to 0-5V for the QuNexus.

QuNexus + QuNeo Synergy

The QuNexus and QuNeo are both KMI products and share:

• Same editor software family (QuNexus Editor cross-compatible conceptually)
• CoMA mode for MIDI learn
• SysEx preset structure (similar but not identical)

Unlike the QuNeo, the QuNexus does NOT have SysEx for preset upload — presets are stored on-device via the editor.

Reference

• Manual: ~/Downloads/current_music_docs/qunexus.pdf
• Note: QuNexus is from Keith McMillen Instruments (same manufacturer as QuNeo)