Soliton plugin interface, showing the propagation visualizer, the in-loop filter, the dispersion and saturator stages, and the Sustain, Spread, and Focus controls

Live · pulse balance

driftingdispersion > saturation

Dispersion 0.40

Sustain 0.50

This is the plugin's interface. The mechanism behind it: dispersion spreads the wave, saturation refocuses it, and when the two come into balance the repeat neither smears nor decays. For the full derivation, read the audio mechanism note.

Soliton balances dispersion against saturation inside a feedback loop, so each repeat reshapes itself instead of decaying into mush. A cascade of allpass stages spreads the wave; saturation pulls it back; a dynamic stabilizer holds amplitude steady. The behavior follows from the Korteweg-de Vries equation, ∂u/∂t + u·∂u/∂x + ∂³u/∂x³ = 0, the equation that describes solitary waves in shallow water. For the deeper technical explanation, read the audio mechanism note or the Russell history note.

A repeat that reshapes itself.

01 · spread

Disperse

A cascade of allpass stages spreads the wave on each pass through the loop.

02 · refocus

Saturate

Saturation pulls the smeared signal back into a coherent pulse.

03 · sustain

Hold

A dynamic stabilizer holds amplitude, so the line neither dies nor runs away.

04 · sculpt

Shape

A filter inside the loop and four saturation shapes change the timbre on every recirculation.

What Soliton does differently.

Self-sustaining equilibrium.

A dynamic stabilizer adjusts feedback gain on every cycle, so the line neither decays into silence nor runs into howl. Set Sustain and walk away.

Repeats that evolve.

An allpass cascade spreads the wave on each pass; saturation refocuses it. A real filter inside the loop sculpts what survives, so every recirculation changes the timbre without changing the level.

Four saturation shapes.

Warm, Tape, Glass, Fold. Each produces a different evolution arc as repeats stack and stabilize, from warm utility to crystalline grit.

A tail you can sculpt.

A two-knob filter, Lo Cut and Hi Cut, sits inside the feedback loop with selectable slope and drag-handle resonance. Repeats darken, brighten, or pinch around a resonant peak as the shape evolves.

Hear it hold.

Real captures

Each demo pairs the same source dry and processed. Toggle between takes to hear time, sustain, focus, and spread shape the repeats.

Analog performance · arp

Arpeggiated analog synth, frequency and resonance modulated.