Filament — Polyphonic Karplus-Strong Synth

Filament — Polyphonic Karplus–Strong based instrument.

Filament is a polyphonic Max for Live instrument built around the Karplus–Strong algorithm, designed for creating plucked, resonant, and evolving tonal textures.

At its core, Filament generates string-like and percussive tones shaped by dampening and brightness controls. The instrument operates across a range of just over three octaves, where it maintains stable and musical pitch behaviour before naturally drifting into more unstable, experimental territory.

A dedicated modulation envelope drives a secondary resonant filter, allowing for dynamic tonal shaping that responds to each note. This, combined with frequency modulation (FM) with adjustable depth, introduces harmonic complexity and controlled instability — pushing the sound from clean plucks into more ethereal, shifting textures.

Filament also features a stereo movement section, designed to introduce width, drift, and spatial motion. Rather than static panning, this creates a sense of evolving placement within the stereo field, contributing to a more immersive and organic sound.

Each processing stage includes its own wet/dry control, enabling precise blending between the raw Karplus–Strong signal and the processed output. This allows Filament to move between defined, percussive tones and diffuse, atmospheric soundscapes.