LuSID Synthesizer

LuSID Synthesizer — a SID-inspired SwiftUI synth with a synthwave heart.

Eight-voice polyphony with detune-and-spread unison, audio-rate filter envelope, classic SID-flavoured ring modulation and pulse-width modulation, plus a built-in 4 to 64-step sequencer and tape-style delay, chorus, distortion, and lush reverb. Wrapped in a neon Liquid-Glass interface that matches what's playing — magenta sequencer steps that bloom lime when active, a gradient cyan oscilloscope that traces your output in real time, and a synthwave horizon that rolls under the step grid.

FOUR TABS

SYNTH — oscillator (triangle, sawtooth, square, noise) with PolyBLEP anti-aliasing. Custom Cytomic state-variable filter (low-pass, high-pass, band-pass, notch) with drive and self-oscillating resonance. Audio-rate filter envelope. LFO with pitch, cutoff, PWM, and pan destinations. Ring modulation. Distortion (lo-fi, broken, cubed, bitcrush, mangled). Chorus. Delay. Reverb (plate, room, hall, cathedral). Big rotary knobs, all the modulation routing visible.

SEQUENCER — 4 to 64 steps. Tap-to-place notes with the chromatic note picker. Per-step ratchets (1x, 2x, 3x) and held-legato notes for gate-length variation. Tempo from 60 to 440 BPM, gate length 5 to 150 percent of step.

KEYBOARD — two-octave touch piano with multi-touch chords and slide-to-play, velocity slider, octave switcher (C2 to C6).

RECORD — capture everything you hear (filter, drive, delay, reverb, the full chain) to a WAV file in the app's Documents folder, then share via the iOS share sheet. 5 to 60 seconds per take.

LuSID is built for the moments when you want to make sound, not learn software. No menus, no preset hunting, no tutorials. Tap a step, sweep a knob, hold a key. The app treats every parameter as performance.

NO ACCOUNTS. NO ANALYTICS. NO TRACKING. NO ADS. LuSID does not collect any data, make any network requests, or contain any third-party SDKs. Recordings stay on your device until you choose to share them.