FoldSpace

Foldspace — Phase Modulation × Wavefolding Processor

Feed it anything. It phase-modulates itself, folds the result three different ways, and feeds that back in.

Foldspace is one signal chain with a wavefolder available at three separate points inside it — on the modulator, on the main output, and inside its own feedback loop — all continuously variable and all active at once if you want. The input can phase-modulate itself directly, drive an internal pitch-tracked oscillator, or follow incoming MIDI as a genuine bass synth voice. The range runs from subtle harmonic thickening all the way to self-oscillating, feedback-driven growls that respond to whatever you throw at them — built around a pitch-tracking core (YIN-based, tuned for bass and monophonic material) that keeps everything locked to what you're actually playing.

Core Signal Path

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• Three Wavefold Insertion Points — fold the modulator bus, the main PM output, and the feedback return independently. Not three modes: one continuous space, with the "classic" fold-the-output / fold-the-modulator / fold-the-feedback patches as corners of it.
  
• Dual Carrier PM — blend between phase-modulating the input signal itself (via a modulated delay line — true PM on arbitrary audio, drums included) and an internal oscillator played by the input's envelope or by MIDI.
  • Pitch System — TRACK (live pitch detection, holds its last confident value through silence and noise), MIDI (mono, last-note, glide-capable), or FREE (manual Hz) — with glide from instant snap to slow, seasick drift.
  • Self-Reinforcing Feedback Loop — the folded wet output can return into the modulator bus, damped and tone-shaped, for growls and near-self-oscillation that stay bounded and controllable.
    
  • Antialiased at the Core — every fold stage uses first-order antiderivative antialiasing on top of switchable 2×/4× oversampling, so the folding stays clean even pushed hard.

  Built to Watch, Not Just Hear

  Two live displays sit above the controls: a transfer curve for the main fold stage that highlights, in real time, exactly which portion of the curve your material is currently traversing — and a modulator oscilloscope showing the actual waveform about to drive the PM stage, after its own fold. Change a wave shape, a ratio, or a fold amount and watch precisely what's about to happen to your signal before it happens.

  Highlights

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  • MIDI-playable bass voice — route MIDI to Foldspace, set Carrier to the internal oscillator, and a drum loop (or anything else) plays a synth bass line that follows your clip.
    
  • BPM-sync on the modulator turns PM into tempo-locked, phaser-like rhythmic motion instead of a static harmonic effect.
    
  • Ducked, equal-power Dry/Wet with a latency-matched dry path — parallel blends stay phase-coherent, not smeared.
  • 10 factory presets spanning the whole range: subtle low-end glow (Melange), clean parallel thickening (Stillsuit), a MIDI-playable sub voice (Arrakis Sub), self-modulating growl (Sandworm), metallic clangor (Navigator), and feedback-driven ringing textures.

  What It's For

  Bass sound design and reinforcement, self-modulating growl and distortion textures that lock to the source material, MIDI-driven synth-bass layering under audio, rhythmic tempo-synced PM effects, metallic and bell-like inharmonic textures, and feedback-driven drones that stay musically controllable at the edge of self-oscillation.

  Foldspace is donation-ware — free to use, no strings attached. If it earns a place in your workflow, a tip is always appreciated: buymeacoffee.com/brittnell

  Format: VST3 (Windows & macOS) | Current version: 1.0.0.