Fourth State Electronics Mk I MIDI controller — top view showing 16-pad grid, five knobs, and touchscreen

Mk I

A standalone MIDI controller designed to run your whole live setup. Three independent outs, per-port everything (routing, tuning, chord gen, filter, arp, clock), and a touchscreen for live edits — no laptop, nothing to install. Small enough to sit on top of your keyboard.

Discover

Every port. Every feature. Independently.

One MIDI input, three MIDI outputs. Every port carries the full processing chain — zone the keyboard by note range, retune per port, shape velocity, filter unwanted messages, expand notes into chords, assign knob CCs, and send tempo-synced clock. Configure per port, per preset.

Signal flow: master keyboard into the FSE Mk I, routed out to a synthesizer, a drum machine, and a MIDI effects unit. Every port carries the full processing chain (zone, transpose, program, CC assignment, velocity, MIDI filter, tuning, chord generator, arp, clock).
Fourth State Mk I — top view with physical dimensions (5.9 × 4.5 in)
Fourth State Mk I — back panel with physical dimensions (2.3 in tall). MIDI OUT A/B/C, MIDI IN, USB-C 5V power, and power switch.

Specifications

MIDI outputs
3 × 5-pin DIN (A, B, C)
MIDI input
1 × 5-pin DIN, optoisolated, forwarded to all outputs
Pads
16 RGB-lit programmable pads
Knobs
5 analog potentiometers with pickup mode
Display
1.9" 320×172 touchscreen
Memory
microSD card, 4 GB
Banks
16
Presets per bank
16
Total presets
256
Onboard features
Velocity curves · Per-port arp · MIDI filter · Chord generator · Latch · Panic · MIDI clock
Power
USB-C, 5 V DC
Enclosure
Anodized aluminum
Dimensions
5.9 × 4.5 × 2.3 in (150 × 114 × 58 mm)
Weight
5 lb

Capability

Built for the stage.
Designed for the studio.

01

Three independent MIDI outs

Ports A, B, and C — each with its own mode, note zone, transpose, program change, tuning, velocity curve, arp, MIDI filter, and chord generator. Route any part of your keyboard to any port, all independently.

02

Sixteen backlit pads

A 4×4 grid of RGB-lit programmable pads. Sixteen presets per bank, per-pad color and note assignment. Doubles as an edit-mode nudge grid: fine on the sides, coarse ±10 in the middle.

03

Five programmable knobs

Assign any knob to any CC on any port, with a startup value the FSE recalls on preset change. Pickup mode stops value jumps — the knob waits until you catch up before it starts transmitting.

04

On-device touchscreen editor

320×172 IPS display. Edit notes, colors, knob assignments, tunings, velocity curves, arps, filters, chord generators, and MIDI routing right on the box. No laptop, no DAW, no reflash.

05

Microtonal tunings per port

12-EDO (standard), 19-EDO, 24-EDO quartertones, 31-EDO, 5-limit Just Intonation, Pythagorean, Slendro, Pelog. Each output can run a different tuning at the same time.

06

Velocity, arp, MIDI filter, chord generator

Per-port. Shape dynamics with curves, gain and offset. Arpeggiate held chords with rate, gate, and latch. Block specific CCs, PC, PB, or aftertouch. Expand single notes into 12 chord voicings.

07

Panic — one gesture, all silent

Hold buttons 1 and 16 for half a second and every port sends All Notes Off, Reset Controllers, and sustain-off on every channel. Works from any screen. Stuck notes are one gesture away from gone.

08

MIDI clock — master or slave

Generate a rock-solid 24 PPQ clock and route it to any combination of the three outs, or slave the whole rig to external clock on MIDI IN. Tap-tempo from any pad button. Drum machines, delay pedals, and the onboard arp all lock to the same beat.

09

Softload — browser companion

Edit banks with a keyboard and mouse, back up your whole SD card in one click, and flash new firmware from the browser. Runs fully offline in Chrome or Edge. No install, no drivers.

Order

Handbuilt to order.
Limited first run.

Each Mk I is assembled, flashed, and bench-tested by hand before it leaves. Handbuilt to order — ships in 1–3 weeks