A polyphonic Eurorack module plays several notes at once from one module, so chords and pads no longer need a stack of oscillators, filters and envelopes per voice. You play it over MIDI, and the best ones are also multitimbral: several different sounds at the same time. OXI Coral, for one, fits 8 voices and 27 engines in 14HP.
Written by OXI. We make Coral, so we say where the others are stronger. Facts about other makers' modules come from their own pages, checked on 2 October 2026.
.sq{--l:#f1f1f138;--m:#f1f1f180;--t:#f1f1f1db;font-size:17px;line-height:1.65;color:var(--t)}.sq p{margin:0 0 22px;font-size:17px;line-height:1.65;color:var(--t)}.sq a{color:#f1f1f1;text-decoration:underline;text-underline-offset:3px}.sq h2{color:#f1f1f1;margin:0 0 28px;font-size:34px;line-height:1.08;letter-spacing:-.04em;font-weight:400}.sq h3{color:#f1f1f1;margin:34px 0 10px;font-size:21px;line-height:1.25;letter-spacing:-.02em;font-weight:500}.sq .k{margin:64px 0 14px;padding-top:24px;border-top:1px solid var(--l);font:11.5px/1.4 Fragment Mono,monospace;letter-spacing:.08em;text-transform:uppercase;color:var(--m)}.sq .k.first{margin-top:56px}.sq figure{display:block;width:100%;max-width:100%;margin:8px auto 36px}.sq .cv img{aspect-ratio:16/9;object-fit:cover}.sq .cv.t img{aspect-ratio:16/10}.sq figcaption{margin-top:12px;font:11.5px/1.4 Fragment Mono,monospace;letter-spacing:.04em;color:var(--m);text-align:left}.sq img{border-radius:6px;display:block;width:100%;height:auto}.sq .st{display:flex;flex-wrap:wrap;gap:8px;margin:6px 0 32px}.sq .st div{flex:1 1 150px;box-sizing:border-box;padding:20px 18px;border:1px solid var(--l);background:#f1f1f10f;font:11px/1.45 Fragment Mono,monospace;letter-spacing:.06em;text-transform:uppercase;color:var(--m)}.sq .st b{display:block;margin-bottom:10px;font:400 28px/1.1 Work Sans Variable,Arial,sans-serif;letter-spacing:-.04em;text-transform:none;color:#f1f1f1}.sq .sw{overflow-x:auto;margin:0 0 14px}.sq table{width:100%;border-collapse:collapse}.sq .cmp{min-width:740px;table-layout:fixed}.sq .cmp th{padding:12px 10px;text-align:left;vertical-align:bottom;border-bottom:1px solid #f1f1f1;font-size:14px;font-weight:500;color:#f1f1f1}.sq .cmp td{padding:12px 10px;vertical-align:top;border-bottom:1px solid var(--l);font-size:13px;line-height:1.5;color:var(--t)}.sq .cmp th:first-child,.sq .cmp td:first-child{position:sticky;left:0;width:92px;padding-left:0;background:#010101;font:10.5px/1.4 Fragment Mono,monospace;letter-spacing:.06em;text-transform:uppercase;color:var(--m)}.sq .cmp th:nth-child(2),.sq .cmp td:nth-child(2){background:#f1f1f11a;color:#f1f1f1}.sq .cmp td:nth-child(2){font-size:13px;font-family:Work Sans Variable,Arial,sans-serif;letter-spacing:0;text-transform:none}.sq .cmp .na{color:var(--m)}.sq .note{margin:0;font:11.5px/1.4 Fragment Mono,monospace;letter-spacing:.04em;color:var(--m)}.sq .fx td{padding:16px 0;vertical-align:top;border-top:1px solid var(--l);font-size:16px;line-height:1.6;color:var(--t)}.sq .fx td:first-child{width:104px;padding-right:14px;font:11.5px/1.4 Fragment Mono,monospace;letter-spacing:.06em;text-transform:uppercase;color:var(--m)}.sq .gd td{padding:20px 0;vertical-align:top;border-top:1px solid var(--l);font-size:15.5px;line-height:1.6;color:var(--t)}.sq .gd td:first-child{width:30%;padding-right:18px;font:11.5px/1.5 Fragment Mono,monospace;letter-spacing:.06em;text-transform:uppercase;color:var(--m)}.sq .gd b{display:block;margin-bottom:8px;font:400 22px/1.2 Work Sans Variable,Arial,sans-serif;letter-spacing:-.03em;color:#f1f1f1}.sq .gd.s td:first-child{width:24%}.sq .gd tr:last-child td{border-bottom:1px solid var(--l)}.sq .btn{display:inline-block;margin:4px 12px 14px 0;padding:14px 22px;border:1px solid #f1f1f1;border-radius:999px;text-decoration:none;font:12px/1 Fragment Mono,monospace;letter-spacing:.08em;text-transform:uppercase;color:#f1f1f1}.sq .btn.f{background:#f1f1f1;color:#010101}.sq .duo{display:flex;gap:10px;margin:8px 0 8px}.sq .duo div{flex:1 1 0;min-width:0}.sq .duo img{aspect-ratio:1/1;object-fit:cover}.sq .ln{display:flex;gap:14px;align-items:flex-start;margin:6px 0 10px;padding:28px 24px 20px;border:1px solid var(--l);background:#f1f1f10f}.sq .ln figure{margin:0;min-width:0}.sq .ln figcaption{margin-top:12px;font-size:10.5px;line-height:1.4;color:var(--t)}.sq .ln figcaption span{display:block;margin-top:2px;color:var(--m)}.sq .pb{display:flex;gap:30px;align-items:flex-start;margin:0 0 8px}.sq .pb .pi{flex:0 0 auto}.sq .pb .pi img{border-radius:3px}.sq .pb .pt{flex:1 1 0;min-width:0}.sq .pb .pt>p:first-child{margin-top:0}@media(max-width:700px){.sq h2{font-size:28px}.sq .ln{padding:16px 12px 12px;gap:8px}.sq .ln figcaption{font-size:9px}.sq .pb{flex-direction:column;gap:18px}.sq .duo{flex-direction:column}.sq .btn{display:block;text-align:center}.sq .cmp{min-width:0}.sq .cmp thead{display:none}.sq .cmp,.sq .cmp tbody,.sq .cmp tr{display:block}.sq .cmp tr{margin:0 0 12px;padding:14px 16px;border:1px solid var(--l)}.sq .cmp td{display:block;padding:7px 0;border:0}.sq .cmp td:first-child{position:static;width:auto;padding:0 0 8px;margin-bottom:6px;border-bottom:1px solid var(--l);background:none;color:#f1f1f1}.sq .cmp td:nth-child(n+2):before{display:block;font:10px/1.4 Fragment Mono,monospace;letter-spacing:.06em;text-transform:uppercase;color:var(--m)}.sq .cmp td:nth-child(2){background:transparent}.sq .cmp td:nth-child(2):before{content:"OXI Coral"}.sq .cmp td:nth-child(3):before{content:"Knobula Poly Cinematic"}.sq .cmp td:nth-child(4):before{content:"Expert Sleepers disting NT"}.sq .cmp td:nth-child(5):before{content:"Mutable Instruments Plaits"}.sq .gd td:first-child{display:block;width:auto;padding:20px 0 0;border-top:1px solid var(--l)}.sq .gd td{display:block;border-top:0;padding:6px 0 0}.sq .gd tr:last-child td:last-child{padding-bottom:20px}.sq .fx td{display:block;padding:0}.sq .fx td:first-child{width:auto;padding:16px 0 4px;border-top:1px solid var(--l)}}
8Coral voices, polyphonic and multitimbral
27engines, up to 10 loaded at a time
14 HPCoral width in the rack
4ways to get chords compared
The short answer
One module, several notes at once
A polyphonic Eurorack module plays several notes at once from one module, so chords and pads no longer need a stack of oscillators, filters and envelopes per voice. You play it over MIDI, and the best ones are also multitimbral: several different sounds at the same time. OXI Coral, for one, fits 8 voices and 27 engines in 14HP.
Written by OXI. We make Coral, so we say where the others are stronger. Facts about other makers' modules come from their own pages, checked on 2 October 2026.
OXI Coral, an 8-voice polyphonic, multitimbral Eurorack module. Photo by OXI Instruments.
01 / The problem
Why polyphony is hard in Eurorack
One CV and gate pair carries one note. A four-note chord, built the classic way, means all of this:
4oscillators
4filters
4envelopes
4VCAs
Plus a MIDI to CV converter with four outputs. It sounds great and it eats HP, cables and budget. A polyphonic module does the voice allocation inside, and takes the chord over a single MIDI cable.
02 / The checklist
What to look for
VoicesHow many notes at once. 8 is enough for full chords with release tails.EnginesOne sound type, or many to choose from per patch.Multitimbral partsCan the voices split into separate sounds, say a bass, a pad and a drum part, each on its own MIDI channel and engine?MIDI and MPEMIDI does the polyphony. MPE adds per-note pitch, pressure and slide from an MPE controller.CVPitch and gate in for mono use, CV over parameters, and a way to bring chords in from CV if you have no MIDI.EffectsReverb and delay on board save more HP.WidthHP is the real cost in a case.
03 / The line-up
Four ways to get chords in a rack
Panels drawn to the same scale, so width in the picture is width in your case. Images and widths: ModularGrid.
OXI CoralKnobula Poly CinematicExpert Sleepers disting NTMutable Instruments PlaitsMakerOXI InstrumentsKnobulaExpert SleepersMutable InstrumentsWhat it is8-voice polyphonic, multitimbral synth8-voice polyphonic synthMulti-function module that runs several algorithms at once, polysynth includedSingle-voice macro oscillatorVoices8, up to 8 oscillators each (64 total)8, 56 oscillatorsNot listed1 (with a chord generator model)Sounds27 engines, up to 10 loaded: analog-style, FM with DX7 patches, wavetable, strings, piano, drums, samplesSupersaw, detuned square or pulse, tonewheel organAlgorithms you add like plug-ins16 synthesis modelsDifferent sounds at onceYes, voices split into parts, each part with its own engineNot listedYes, several algorithms at onceNoEffectsReverb, chorus, delay with per-voice sendReverbReverb and delay as separate algorithmsNo (internal low-pass gate)ControlMIDI in, MPE, 1V/Oct and trigger in, MIDI CC on every parameterTRS MIDI in, CV for pitch, gate, filter and chord, MIDI CC12 inputs, 6 outputs, MIDI via the included breakoutCV onlyWidth14HP12HP22HP12HP
Specs checked on 2 October 2026, from each maker's own page. Plaits width from ModularGrid.
04 / Module
OXI Coral: one module, a whole track
Coral is an 8-voice module with up to 8 oscillators per voice. Its designers started from their admiration for Mutable Instruments' Plaits, a module from another maker, and built something much larger. You pick from 27 engines, up to 10 loaded at a time, chosen in the Firmware Updater: Moog-style 3-VCO analog, SH-101, OB-VA, FMX7 for your DX7 patches, wavetables (up to 96 to pick from), strings with Smart Chord, PianoZ, drum synths and WavPlayer for your own samples.
Split the 8 voices into parts and each part runs its own engine, with its own filter, amp, envelope, FX send and pan, so one 14HP module plays bass, chords and drums together. Every voice has a send to the onboard reverb, chorus and delay. Every parameter answers MIDI CC, an MPE controller gives per-note expression across all 8 voices, and a 1V/Oct plus trigger input takes CV.
OXI Coral. Photos by OXI Instruments.
Others strongerPoly Cinematic is narrower at 12HP and simpler to dial in. disting NT has many more CV inputs and outputs for patching.SuitsSmall cases, multitimbral patches, players who sequence from an OXI ONE MKII or any polyphonic MIDI sequencer.
05 / Module
Knobula Poly Cinematic: the pad machine
An 8-voice synth with 56 oscillators in 12HP: a 7-oscillator supersaw per voice, a detuned square or pulse and a tonewheel organ, three filter types and a built-in reverb. Knobula built it to get rich pads and stabs fast, without scrolling presets. Its chord memory holds 8 chords under CV and gate, so you can play chords from a CV sequencer, and a TRS MIDI input plays it like a full polysynth.
StrongerSpeed to a big pad, CV chord memory, 12HP.LimitsOne sound family; multitimbral parts are not listed.SuitsAmbient and cinematic players who want one lush voice.
06 / Module
Expert Sleepers disting NT: the toolbox
The disting NT runs a list of algorithms at once, much like plug-ins in a DAW, with 12 inputs and 6 outputs on a 22HP panel. Expert Sleepers says it "makes a really good MIDI polysynth", next to its sampling, reverbs, delays and utilities. MIDI comes in through the breakout module included in the box.
StrongerCV patching depth and range of functions.Limits22HP, and the voice count for its polysynth is not listed on the product page.SuitsPatchers who want one module for many jobs, poly voice included.
07 / Module
Mutable Instruments Plaits: the mono reference
Plaits is a macro oscillator made by Mutable Instruments: 16 synthesis models, 8 for pitched sounds (including a chord generator) and 8 for noise and percussion, with an internal low-pass gate. It plays one voice. Its chord model gives you chords from a single voice, not independent notes, which is why players who want real polyphony look further.
SuitsA single expressive voice. For true polyphony, look at the modules above.
08 / Approach
The classic way: build it voice by voice
Four or eight sets of oscillator, filter, envelope and VCA, fed by a MIDI to CV converter with enough outputs. Fully analog and fully patchable. Expect a large case and many cables.
09 / Sequencing
How to sequence a polyphonic module
Over MIDI from any polyphonic sequencer or a keyboard. On the OXI ONE MKII, three modes do the work:
PolyUp to 7 voicesPoly mode writes chords and lines with up to 7 voices.ChordProgressionsChord mode builds progressions from a palette of voicings.MultitrackOne channel per partMultitrack drives each Coral part on its own channel.
10 / Questions
FAQ
What is the difference between polyphonic and multitimbral?
Polyphonic means several notes at once. Multitimbral means several different sounds at once, each on its own MIDI channel. Coral is both: 8 voices that split into parts, each running its own engine, with its own filter and effects send.
Do I need MIDI for polyphony in Eurorack?
Usually yes. One CV and gate pair carries one note, so a chord over CV needs one pair per note. Poly modules take the whole chord over one MIDI cable. Some, like the Poly Cinematic, also recall stored chords from CV.
How many engines can Coral run at once?
Coral has 27 engines and holds up to 10 at a time. You choose your 10 in the Firmware Updater, which builds a custom firmware for your module.
11 / Next step
Hear every engine
Hear every engine and watch the tutorials on the OXI Coral page. Choosing a sequencer for it too? Read the hardware sequencer comparison.
