Synthimatic

Synthimatic is a free visual subtractive synth for macOS and Windows (VST3, AU, Standalone), built so you can SEE what every knob does while you hear it.

The big lab display in the middle shows the waveform built from your current oscillators, the output stage and the live spectrum. Change the filter and watch the harmonics melt. Open the amp envelope and watch the shape breathe. Built-in hints explain what each section does while you play, which makes Synthimatic a synthesis classroom that happens to be a fully usable instrument.

Under the hood: two oscillators (sine, triangle, saw, square) plus noise, a resonant filter (24 dB and 12 dB low-pass, 12 dB high-pass), separate amp and filter envelopes, a tempo-syncable LFO, mono/poly voice modes, light and dark themes, and factory presets that double as lessons.

Synthimatic is free forever: no licence key, no telemetry, no upsell. The dream is simple: anyone who loves synths, anywhere in the world, can have a beautiful visual synth for free, learn, and make amazing sound.