PolyPad
A polyphonic chord-pad synth. Play a single root note and PolyPad voices a full chord of up to 8 stacked notes, with inversions, detuned supersaw layers, two LFOs and a state-variable filter.
Available on: Track 9
Built on: CTAG ChordSynth — chord table from MI Plaits chord engine, MI-style supersaw oscillator, MI Braids SVF filter.
Character
Pick a chord shape, pick an inversion, play a single root note — PolyPad voices a full chord with up to 8 stacked notes per trigger. Detuned supersaw layers produce a rich, classic-trance chord pad; turn detune down and the shape stays clean for film-score strings.
Two LFOs can modulate filter cutoff and pitch, the SVF gives you LP / BP / HP shaping, and a per-chord-trigger ADSR envelope makes PolyPad equally at home on slow pads, plucky stabs or rhythmic chord stabs.
Available chord shapes: OCT · 5 · sus4 · m · m6 · m7 · m9 · m11 · 69 · M9 · M7 · M6 · M · D7 · A7 · HDim7 · Dim7 · Dom7 sus
Parameters
The default PolyPad performance macro is organised as 4 pages × 4 controls.
Chord
| Parameter | What it does |
|---|---|
| Chord | Chord type (18 shapes, see list above) |
| Inv | Chord inversion |
| Nnotes | Number of stacked notes (1–8) |
| Detune | Supersaw detune amount |
Filter
| Parameter | What it does |
|---|---|
| Cutoff | Filter cutoff frequency |
| Reso | Filter resonance |
| Type | LP / BP / HP |
| EG Flt | Envelope → cutoff amount |
Env
The ADSR envelope shapes each triggered chord. Re-triggered on every note, not held from a key gate.
| Parameter | What it does |
|---|---|
| Attack | Time from trigger to envelope peak |
| Decay | Time from peak down to sustain level |
| Sustain | Level held while the chord sustains |
| Release | Time from note-off back to zero |
Motion
Two LFOs for filter cutoff and pitch modulation.
| Parameter | What it does |
|---|---|
| L1 Spd | LFO 1 speed (modulates pitch / vibrato) |
| L1 Amt | LFO 1 depth |
| L2 Spd | LFO 2 speed (modulates filter cutoff) |
| L2 Amt | LFO 2 depth |
Lock
chordper step to turn a single held note into a full chord progression — the fastest way to write chord sequences on a groovebox.
See also
- Mono Synth — monophonic Braids-based alternative.
- Wavetable Osc — pad-capable wavetable voice.
Origin & credits
PolyPad is CTAG’s ChordSynth engine, a custom chord voice by Robert Manzke (CTAG, 2020, GPL 3.0) that combines several Mutable Instruments building blocks:
- Chord table from Plaits’ chord engine — CTAG’s own source comment reads “from plaits chord engine augmented with inversions”. The 18 chord shapes are taken directly from Plaits, with inversion logic added on top.
- MI-style supersaw oscillator (
polypad/MiSuperSawOsc.hpp) using Braids’ parameter-interpolation and resource tables. - Braids SVF filter (
braids/svf.h, MIT). - CTAG ADSR, sine source, voice allocation by Robert Manzke (GPL 3.0).
The CTAG TBD plugin list describes PolyPad as “Dub-like minor pads or smooth long attack / release glue logic strings, 24 voice polyphony.”
- DSP sources:
polypad/ChordSynth.hpp,polypad/MiSuperSawOsc.hpp,braids/svf.h - TBD-16 wrapper:
rack/RackPolyPad.hpp/.cpp - Related reading: Plaits chord engine