Konstrukt Get Konstrukt
Konstrukt app icon

AUv3 + Standalone · iPad & iPhone · formerly MIDIRack

Konstrukt

Build the instrument you play.

Design the surface you play from the KB-1 keyboards, sequence it with a full suite of lanes, give it sound with built-in instruments and your AUv3 plug-ins, mix it on the Rack and record it — then unlock the graph underneath and rewire all of it. Standalone, or as an AUv3 inside your host.

Download on the App Store How it works
  • KB-1 keyboards, sequencers, surfaces you build
  • Instruments, AUv3 hosting, the Rack, recording
  • One graph underneath: MIDI + audio · 80+ nodes · fragments
Konstrukt performance surface with piano, chord pads, MPE keyboards and drum pads.

Factory patches, then House Rig · sequencers, the Seaboard, a hosted AUv3 and the Rack

New in 1.2 · free update

Plug-ins and audio. New sequencers. Fragments.

The biggest update yet, under a new name: MIDIRack is now Konstrukt. It hosts your AUv3 plug-ins and makes its own sound, with the audio side on a new Rack page — and brings four new sequencers and Fragments in the graph editor. Free for existing owners, on iPad and iPhone.

The Konstrukt Rack page on an iPad: a channel row per instrument — Analog, Drums, Analog — each with its input lanes, insert slots, a Reverb send, pan, fader and meter, mute, solo and record arm; the master row below with inserts, a spectrum and Scenes.
The Rack · a channel per instrument

  • Host AUv3 plug-ins — or play its own

    Third-party instruments, effects and MIDI effects run inside the patch with floating windows, presets and bindable parameters. No plug-in at hand? Analog, Wavetable, Drums, MegaSaw, Sampler and Slicer are built in, with Drive, Filter, Delay, Reverb, Compressor, EQ, Chorus and Phaser — each with its own panel.

  • The Rack

    The audio side on one page: a channel strip per instrument with fader, pan, inserts, pre- or post-fader sends to bus strips, sidechain, MIDI Learn, master inserts and scenes you recall with a fade. Hardware synths join as External Instrument channels.

  • Audio in, recording and Ableton Link

    Bring a mic or a guitar in on its own channel, record the master and stems to 24-bit WAV, and run it all from a transport with tap tempo, a metronome with count-in, Ableton Link, MIDI clock in and out, and multi-output routing.

  • Three new ways to sequence

    The Drum Grid puts a whole kit on one card. The Stage Seq is a Metropolis-style lane of pitches and pulse counts. The Chord Seq gains Rhythm, Strum and Voicing layers. Every lane: patterns up to four bars, eight banks, record into patterns, ratchets, custom scales and one patch key to follow.

  • Fragments

    Select a cluster of nodes and Save as Fragment: it collapses to one card with real ports, and the surface cards bound to those nodes come with it. Saved fragments drop into any patch from + → Fragments and stay editable inside. Graph editor unlock.

  • And a new name

    MIDIRack is now Konstrukt — same app, same purchases, same patches. Also in 1.2: players that write a lane from a style, an arp on every keyboard, a MIDI FX slot on every track, New Patch templates, a second oscillator for the Analog and a Wavetable synth.

  • Details in the manual

Signal path · surface → graph

Build the surface.
Wire up the graph.

Graph · what's underneath The graph: signal chains wired from MIDI In through processors to MIDI Out.
Surface · what you touch A performance surface with piano, chord pads, MPE keyboards and drum pads.

The surface

Base app · $7.99

Surfaces you build from the KB-1 keyboards, sequencers, knobs and faders. Built-in instruments and your AUv3 plug-ins on the Rack, with inserts and sends; audio in, recording, Ableton Link. All of it in the base app, standalone and as an AUv3.

Explore the surface

The graph editor

One-time unlock · $7.99

Everything above already runs on a visual canvas — MIDI and audio. Unlock the editor to rewire it: arps, quantizers, LFOs and generators on the MIDI side, effect chains, sends and sidechains on the audio side, and fragments that fold a cluster into one reusable card. The unlock is the editor, nothing else.

Explore the graph

Better together: every keyboard is a routable node, and every knob binds to a graph parameter — and moves when another node drives it.

01 · Play · the KB-1 suite, reborn

Every KB-1 keyboard lives on.

Piano, chord pads, scale keyboard, the MPE Seaboard and Strings, and drum pads — the whole KB-1 Expressive Keyboard Suite, rebuilt as building blocks. Each one is its own routable node: use them alone or combined, process them in the node graph and create a whole new instrument.

The piano keyboard control: two octaves of velocity-sensitive keys.
Keyboard NOTES · LATCH · ±OCT Velocity-sensitive piano with latch and octave shift.
The chord pads control: one pad per scale degree, each playing a full chord.
Chord Pads DIATONIC · 3–4 VOICES Pads locked to your key — one-finger progressions.
The scale keyboard control: evenly spaced bars locked to the current scale.
Scale Keyboard SCALE-LOCKED Scale-locked bars — wrong notes are impossible.
The MPE Seaboard control: a continuous ribbon keyboard with glide, slide and velocity toggles.
Seaboard MPE · GLIDE · SLIDE · XY MPE ribbon with per-note pitch bend and vibrato.
The MPE strings grid control: rows of pads tuned in fourths.
Strings Grid MPE · 4THS · XY Linnstrument-style isomorphic grid with per-note slide and pressure.
The drum pads control: a four-by-four grid of GM drum pads.
Drum Pads GM · CH 10 4×4 GM drum-pad grid on its own channel.

On its own: send notes and CC straight to external synths, apps or hardware.
In the graph: arpeggiate, quantize, echo or split each keyboard to any of 16 channels or MPE.

02 · Sequence · tap-to-edit, on the surface

A full suite of sequencers.

Drum, melody, chord, analog and CC lanes, a Drum Grid that puts a whole kit on one card, a Metropolis-style Stage Seq, a Matrix note grid and a Piano Roll — edited right on the surface, with a moving playhead, microtiming, per-step probability, ratchets and trigger conditions. Play a take in and it lands in a lane; tap ✦ and a player writes one for you.

The Drum Grid: eight drum rows of sixteen steps on one card, with Pattern, Vel, Prob and Ratchet layers.
Drum Grid NEW · 8 ROWS · ONE CARD A whole kit in one sequencer: eight rows with their own notes and mutes, every lane layer per row, banks, rotate and record.
The Stage Seq: eight pitch stages with pulse counts and Hold, Single, Repeat and Rest gate modes.
Stage Seq NEW · 8 STAGES · METROPOLIS Eight stages, each a pitch and a pulse count with a gate mode, ratchet, slide and skip — the pattern's length is the sum of its pulses, so odd phrases come naturally.
A chord sequencer lane stepping through diatonic chords.
Chord Seq I–VII · RHYTHM · STRUM · VOICING One scale degree per step, voiced as triads or 7ths — with new Rhythm, Strum and Voicing layers that decide when and how each chord hits.
A 16-step drum sequencer lane with a moving playhead.
Drum Seq 16 STEPS · PER-PITCH One pitch per lane — branch several for a full kit.
A melody step sequencer lane with per-step pitches.
Step Seq MONO · 0 = REST Monophonic melodies, one pitch per step.
The analog sequencer lane: eight pitch knobs above a root, with accent and slide layers.
Analog Seq 8 KNOBS · RE-ROOTS A knob per step, walked forward, backward, pendulum or random — play a note and the line re-roots live, SH-101 style.
A CC automation sequencer lane drawing a filter sweep.
CC Seq ANY CC Automation lanes — filter sweeps, rhythmic tremolo.
The Matrix note grid: a four-by-four grid of pitches with a traversal playhead.
Matrix 4×4 → 8×8 · XY TRIG A note grid, not a lane — walk it in Rows, Columns, Snake, Diagonal, Spiral or Random order, or trigger cells from XY inputs.
The Piano Roll: a recorded take shown as notes on a piano-roll grid.
Piano Roll RECORD · QUANTIZE · UNDO Play a take in and it lands here, quantized on the way in, with undo of the last take and expression captured. Send it to a lane and fix it in the grid.

These aren't toy step grids.

Per-step depth

Velocity, probability, tie and Elektron-style trigger conditions on every step — with microtiming to nudge it off the grid.

Eight banks, four bars

Banks A–H per lane, each up to four bars long. Set a chain and a lane cycles through on its own — a full arrangement with no extra wiring.

Scenes

Scene Pads flip every lane's pattern bank at once, each lane crossing over on its own downbeat — or on the bar, with launch quantize — for a tight switch.

03 · Arrange · the builder

Same blocks. Your instrument.

Keyboards and sequencers aren't a fixed layout — they're building blocks you arrange on a snapping grid. Every shot below uses the same five blocks: chord pads, piano, drum pads, two faders. Three different instruments.

The Stage Rig patch: chord pads and a 4×4 drum kit in the top row, a piano keyboard and cutoff and volume faders below.
Stage Rig Chords and kit up top, a piano below — everything in reach at once.
The Piano First patch: a full-width two-octave piano on top, with chord pads, a drum kit and two faders in a row beneath it.
Piano First The piano takes the full width; chords, kit and faders tuck underneath.
The One Hand patch: seven tall chord pads dominating the surface, with cutoff and volume faders at the right and a slim piano and drum kit along the bottom.
One Hand Chord pads big enough to play blind, faders beside your thumb.

Auto-layout keeps the surface tidy as you add blocks — and the welcome tour has you adding and binding your first control in about a minute.

04 · Wire · the graph unlock · $7.99 once

Underneath: one graph for MIDI and audio.

A one-time unlock opens the node graph the whole instrument runs on. Wire MIDI In → processors → instruments, then cable their audio through effects to Audio Out — or straight to MIDI Out across 16 channels and MPE. Insert it as an AUv3 in your host and it follows host transport.

Visual graph editor

Wire it like a modular rig

Drag nodes onto the canvas and connect them left to right — MIDI and audio on the same canvas. Splice a processor straight onto a wire, expand a node's ports, tweak parameters inline. Activity LEDs show signal flowing through every node in real time.

  • MIDI wires, green audio cables, amber modulation edges
  • Branch and merge to build complex signal paths
  • Fragments: fold a cluster — and its surface cards — into one card with real ports
Konstrukt graph editor: MIDI In wired through Life, Quantize, Chord and Echo to MIDI Out, with the Life node's inspector open.

Surface ↔ graph bindings

Your surface, wired

This is where the builder pays off: every keyboard you play is already a routable node, and every knob you placed can bind to any parameter in the patch. Modulate a parameter with an LFO and watch the knob physically move.

  • Route the piano through an arp, chord pads to channel 2
  • Bind knobs, faders and XY pads to any node parameter
  • Live scopes on the surface visualize the running patch
A performance surface with a live Lorenz scope, a grid of knobs for arp and echo parameters, and Cutoff and Volume faders.

Audio in the graph

Audio runs through it too

The graph doesn't stop at MIDI. Every instrument has an Audio output: cable it into Drive, Filter, Delay, Reverb or a hosted AUv3 effect, chain effects into each other, split a send off to a bus, key a sidechain, bring a mic or guitar in through Audio In, and end at Audio Out. The Rack is this same routing seen as strips — patch it here when a strip isn't enough.

  • Instruments, Audio In, effects and hosted AUv3s as audio nodes
  • Sends are audio cables with a level; sidechain is a Key port
  • Modulate effect parameters like any other: an LFO on a filter sweep
The graph editor: Drum Grid, Chord Seq, a Piano Roll and MIDI In feed Analog, Drums, Sampler and MegaSaw nodes over MIDI wires; green audio cables run from the instruments through a Reverb send bus, with -5 dB and -8 dB send levels, into Audio Out.

Emergence generators

Patterns that live

Conway's Game of Life, Wolfram rules, a Turing machine, Markov chains, bouncing balls and a Lorenz attractor — generators that evolve instead of loop. Quantize them to your key and they compose with you.

  • Six emergence nodes, all clock-synced
  • Factory patches to start from: Conway Choir, Turing Bass, Berlin School…
  • Run them free before you buy — factory patches play without the unlock
The Conway Choir factory patch: a Game of Life node driving quantized voices, with its colony grid visible on the surface.

05 · The node library · hover a chip to see it expanded

83 nodes, ready to wire.

From MIDI utilities and generative sequencers to instruments and audio effects — every node card below is rendered straight from the app. Expand any node in the editor and each orange ring is a parameter a surface knob or an LFO can drive.

Play

3

Sequence

11

Control

4

Filter & Route

10

Notes

11

Pitch & Scale

3

Generate & Modulate

15

Emergence

6

Instruments

8

Audio FX

10

Utility

2
The Turing node fully expanded: In, Trig and Clock inputs, Out and EOC outputs, and modulatable parameters from Rate to Gate.
One node, expanded — every ◦ ring is a parameter your control surface can drive and other nodes can modulate.

Reference · the parts bin

Every block on the shelf.

For completeness: all 23 blocks you can place on a surface, rendered straight from the app. Long-press any block's edge for its settings; auto-layout keeps the grid tidy as you add more.

Play

6

The six KB-1 keyboards — every one a routable node.

  • The Keyboard control, rendered in the app.
    Keyboard Velocity-sensitive piano with latch and octave shift.
  • The Chord Pads control, rendered in the app.
    Chord Pads One-finger diatonic progressions, locked to your key.
  • The Scale Keyboard control, rendered in the app.
    Scale Keyboard Scale-locked bars — wrong notes are impossible.
  • The Seaboard control, rendered in the app.
    Seaboard MPE MPE ribbon with glide, slide and pressure.
  • The Strings Grid control, rendered in the app.
    Strings Grid MPE Isomorphic grid in 4ths with per-note expression.
  • The Drum Pads control, rendered in the app.
    Drum Pads CH 10 4×4 GM kit on its own channel.

Control

5

Bind each one to a graph parameter — or a raw MIDI CC.

  • The Knob control, rendered in the app.
    Knob CC / PARAM Sweep a node parameter or any CC.
  • The Fader control, rendered in the app.
    Fader CC / PARAM Long-throw level for mixes and filter rides.
  • The XY Pad control, rendered in the app.
    XY Pad 2 × CC Two CCs under one finger.
  • The Button control, rendered in the app.
    Button Toggle or momentary — sends on and off values.
  • The Selector control, rendered in the app.
    Selector Pick waveforms, scales and modes with a stepped switch.

Sequence

6

Sequencer lanes and pattern tools, editable mid-performance.

  • The Steps control, rendered in the app.
    Steps 16 STEPS A sequencer lane's pattern, pad by pad.
  • The Step Mods control, rendered in the app.
    Step Mods Per-step probability, ties and conditions.
  • The Lane+ control, rendered in the app.
    Lane+ The whole lane in one card — pattern and mod layers.
  • The Matrix control, rendered in the app.
    Matrix 4×4 16 knobs editing a Matrix seq's cells, playhead live.
  • The Scenes control, rendered in the app.
    Scenes A–D A–D pads that flip every lane to that pattern bank.
  • The Piano Roll control, rendered in the app.
    Piano Roll Record, play and clear a Piano Roll node's phrase.

Watch

6

Live visualizers, fed straight from the graph.

  • The Monitor control, rendered in the app.
    Monitor Live log of every MIDI event flowing through.
  • The Note Scope control, rendered in the app.
    Note Scope Scrolling piano-roll of the notes an arp or seq is playing.
  • The CC Scope control, rendered in the app.
    CC Scope Oscilloscope for CC curves, one color per CC.
  • The Scope control, rendered in the app.
    Scope Markov trails, bounce physics, attractor orbits — live.
  • The Life Grid control, rendered in the app.
    Life Grid 16×12 Draw a Game of Life seed, watch the colony run.
  • The Register control, rendered in the app.
    Register A Turing machine's note register and playhead.

06 · Get it · one-time purchases, no subscription

Two purchases. Yours forever.

The base app is the whole instrument — surfaces, sequencers, instruments, plug-in hosting, the Rack and recording. The graph editor is a single optional unlock, and it unlocks only the editor. That's the whole price list — no subscriptions, no hidden costs.

Base app

$7.99

  • The six KB-1 keyboards, incl. MPE, on surfaces you build
  • The sequencer suite: Drum Grid, Stage Seq, Chord Seq, Matrix, Piano Roll
  • Analog, Wavetable, Drums, MegaSaw, Sampler, Slicer + eight effects
  • Host your AUv3 instruments, effects and MIDI effects
  • The Rack: inserts, sends, sidechain, scenes · audio in · recording · Link
  • Standalone + AUv3 · CoreMIDI + virtual port

Graph Editor unlock

+ $7.99

  • The full visual graph editor — rewire the instrument
  • 80+ nodes incl. generators & emergence
  • Fragments: a cluster of nodes and cards as one card
  • Audio on the canvas: effect chains, sends, sidechain
  • Surface → graph parameter bindings
  • Save your own graph patches
  • Factory patches run free — try before you buy
Download on the App Store

One-time purchases — no subscription, no hidden costs.

Desk duty · iPad or iPhone → your DAW

The MPE controller already on your desk.

Dedicated MPE hardware runs from the low hundreds to well past a thousand. Konstrukt is $7.99 on the iPad or iPhone you already own — two genuinely expressive MPE surfaces with per-note pitch bend, slide and pressure, playing straight into Logic, Live, Bitwig, Cubase or any CoreMIDI destination.

iPad / iPhone · MIDIRack Out USB (IDAM) or Bluetooth MIDI your DAW

  • One cable. Plug into a Mac, enable the iPad or iPhone in Audio MIDI Setup, done — Konstrukt shows up as a MIDI source. No helper app, no driver. Or go wireless over Bluetooth MIDI.
  • Unlike hardware, the layout isn't welded shut. A Seaboard is a Seaboard forever. Konstrukt is whatever the track needs — MPE ribbon for the lead pass, drum pads for the beat, chord pads to sketch the progression, faders on CC for the mix move. Rearranged in seconds, saved per project.
  • Not just keyboards. The step lanes, chains and scenes clock to your DAW and drive its tracks — a hands-on pattern box beside the timeline.
The MPE Seaboard control: a continuous ribbon keyboard with glide, slide and velocity.
MPE · GLIDE · SLIDE Seaboard ribbon
The MPE Strings control: an isomorphic grid in fourths with per-note slide and pressure.
MPE · GRID IN 4THS Strings grid

FAQ

Good to know

What do I get in the base app, and what costs extra?

The base app ($7.99) is the whole instrument: the six touch keyboards and the surface builder, the sequencer suite, the built-in instruments and effects, AUv3 plug-in hosting, the Rack, recording and Ableton Link. The only thing that costs extra is the visual graph editor, a one-time in-app unlock ($7.99) — a single purchase, not a subscription. You can open and run the factory graph patches before you unlock; adding, wiring and deleting nodes on the canvas, and fragments, are what the unlock opens up.

Wasn't this called MIDIRack?

Yes. MIDIRack became Konstrukt with version 1.2 — the same app, the same purchases and the same patches, under a name that fits what it grew into. Existing owners get 1.2 as a free update; there is nothing to buy again. One thing deliberately keeps the old name: the virtual MIDI port is still called "MIDIRack Out", so DAW and host setups that route it keep working.

I own KB-1 — what does this mean for me?

Konstrukt is a new instrument, not an update to KB-1. Every KB-1 keyboard lives on inside it — piano, chord pads, scale keyboard, the MPE Seaboard and Strings, and drum pads — rebuilt as building blocks you can mix, resize and arrange on one surface, next to a full sequencer suite. KB-1 keeps working as it always has.

Can I use Konstrukt just for the keyboards and controls?

Yes. The performance surface is the base app and a full control-surface and keyboard builder on its own — six touch keyboards, knobs, faders, step grids and more. Send MIDI and CC to external synths, apps or hardware without ever unlocking the graph. It's the successor to the KB-1 Expressive Keyboard Suite.

Can I use just the graph?

Yes, once you unlock it. The graph then works as a standalone processor or AUv3 insert — wire MIDI In → processors → MIDI Out in your host with little or no custom UI. Tempo-synced nodes follow host transport; the MIDI Out node routes 16 channels and MPE. In the standalone app the same canvas carries audio too: instruments into effect chains, sends, sidechains and Audio Out.

Does it make sound on its own?

Yes. The standalone app has a two-oscillator Analog, a Wavetable synth, Drums, MegaSaw, a Sampler and a loop Slicer, plus Drive, Filter, Delay, Reverb, Compressor, EQ, Chorus and Phaser — each with its own panel — and it hosts your own AUv3 instruments, effects and MIDI effects. Every instrument gets a channel strip on the Rack with inserts and sends. It is also still a first-class MIDI source: everything you play and sequence can go out to other apps and hardware.

Can I use it with hardware and other apps instead?

Yes. Every surface and lane can send MIDI out over CoreMIDI, extra output ports and the always-on virtual port, with 16 channels plus MPE, MIDI clock out and Ableton Link — and an External Instrument channel puts a hardware synth on the Rack like any other. Konstrukt can be the brain of a hardware rig, with or without its own instruments in the mix.

Which hosts does the AUv3 work in?

Konstrukt runs as an AUv3 MIDI-processor or instrument plugin in hosts like AUM, Logic Pro, GarageBand, Cubasis, Drambo and Loopy Pro — anywhere that supports MIDI-effect or instrument AUv3s. Plug-in hosting, audio input and recording are the standalone app's.

Do I need to know how to code?

No. Build by hand — lay out a performance surface and touch keyboards, patch the graph underneath, or both. There's no scripting required.

Does it support MPE?

Yes. The MIDI Out node exposes all 16 channels plus an MPE connector, and there are MPE keyboards (a Seaboard-style ribbon and a Linnstrument-style grid) with per-note pitch bend, slide and pressure.

What do I need to run it?

It runs on iPad (iPadOS 17 or later) and iPhone (iOS 17 or later, landscape). Both get the standalone app and the AUv3 plug-in in one purchase — on iPhone the surface plays in landscape, the menubar folds away and sequencer lanes open a full-screen focus editor. A Mac (Apple silicon) version is next.

Can I play it from a computer keyboard?

Yes. On a Mac or an iPad with a hardware keyboard, the usual QWERTY piano plays: A–' are the white keys, W–P the black keys, Z/X shift the octave, C/V step the velocity, and 1–8 / Q–I hit the drum pads. It drives the slide-up keyboard when that's open, otherwise the last keyboard you touched.

Want the full picture? Read the Konstrukt manual.

Touch the surface.
Wire the graph.

Start with an instrument you can play in seconds — keyboards, sequencers, sounds and a rack. Go as deep as a patchable graph when you're ready.

Download on the App Store Read the manual