LeSynth - Fourier
Key Features
- Fourier-based additive synthesis engine for drawing tones from harmonic partials rather than preset oscillator shapes
- 64 editable harmonics with per-partial amplitude and phase controls for detailed spectral shaping
- Constant, sine, and Wobble curve behavior lets each harmonic move over time for evolving timbres
- Real-time harmonic and assembled-waveform displays show how edits change the sound as you play
- Polyphonic voice allocation, MIDI input, and an on-screen piano make it usable as a playable instrument
- Resizable egui interface and background computation keep the editor responsive during sound design
Description
LeSynth - Fourier is an open-source additive synthesizer from Jakub Hlavnicka that builds sound from editable Fourier harmonics instead of fixed oscillator models. It runs as a VST3 instrument on macOS, Windows, and Linux, with current release downloads hosted from the official GitHub repository.
The core editor gives you 64 harmonics with individual amplitude and phase control, plus constant, sine, and Wobble curve behavior for time-varying movement. Real-time harmonic and waveform plots make it useful both as a sound-design instrument and as a visual way to understand how partials shape timbre.
Version 1.2.0 adds CLAP support in the release package, fixes Windows VST scanning, improves dynamic GUI resizing, and expands the fine parameter ranges. The README also notes MIDI input, a click-to-play piano keyboard, polyphonic voice allocation, automatic gain scaling, and background computation for smoother real-time playback.
Use it when you want precise harmonic stacks, evolving organ-like tones, formant-style leads, synthetic pads, or experimental partial motion without opening a large commercial workstation synth. KVR lists it as Apache 2.0 licensed, open source, and free for commercial and personal use.
Frequently Asked Questions
What kind of synth is LeSynth - Fourier?
It is an additive synthesizer that constructs sounds from Fourier harmonics. Instead of starting with saw, square, or wavetable oscillators, you shape the amplitude and phase of individual partials and watch the resulting waveform update.
Does LeSynth - Fourier support CLAP as well as VST3?
The official 1.2.0 release includes CLAP builds for macOS, Windows, and Linux, and KVR lists both VST3 and CLAP support. The SSA download buttons mirror the VST3 builds because those are the standard installs documented in the release notes.
Is this more useful for music production or learning synthesis?
It can serve both roles. The real-time plots and exposed harmonic controls make it educational, while the polyphonic engine, MIDI input, Wobble modulation, and 64 harmonics are practical for pads, organs, leads, and experimental sound design.
What changed in version 1.2.0?
Version 1.2.0 fixed Windows VST scanning, restored proper dynamic GUI resizing, added Wobble modulation, improved the interface, extended fine control ranges, and added CLAP support. These changes make it a better fit for normal DAW use than the initial release.
