Bitcrust changelog

Release notes for Bitcrust.

v0.1.0 — 2026-04-16

Initial release.

Synth engine

  • In-house MOS 6581 / 8580 DSP core (bitcrust::sid) — clean-room implementation from public datasheets, not a reSIDfp wrapper.
  • 12-voice polyphony with oldest-voice stealing, 3 oscillators per voice, each running its own chip instance for true per-oscillator volume, pan, and tuning.
  • Multi-mode TPT state-variable filter with simultaneous LP / BP / HP outputs and per-chip-model drive character (6581 tanh / 8580 clean).
  • Voice modes: Poly, Mono (retrig), Legato. Unison 1–8 voices with detune and stereo spread. Glide: Off / Always / Legato, 0–2000 ms.
  • 64-bit internal processing with peak-reading soft limiter, per-voice DC blocker, and anti-click voice fade-in.

Modulation

  • 8-slot modulation matrix with bipolar depth and per-slot bypass.
  • 3 global LFOs (7 shapes, free-run or tempo-sync, retrigger toggle).
  • Dedicated per-voice modulation envelope (ADSR).
  • MIDI sources: velocity, poly aftertouch, mod wheel, channel aftertouch, pitch bend.
  • 40+ destinations including per-VCO and global parameters.

Effects

  • 6-slot post-synth effects rack, freely reorderable.
  • Effect types: Drive (5 shapes), Bitcrusher, Delay (tempo-sync), Chorus, Reverb, Compressor, Limiter.
  • Per-slot bypass and dry/wet mix.

Performance & MIDI

  • Tempo-synced arpeggiator: Up / Down / UpDown / Random, 6 rate divisions, gate, 1–4 octave range.
  • 16-step sequencer with per-step pitch, gate, velocity, and slide.
  • MIDI-learn on every parameter. MIDI panic button.
  • Velocity curves: Linear, Soft, Hard, S-Curve, Fixed.
  • A4 reference tuning: 415–465 Hz. Master transpose: ±24 st.

Presets

  • 98 factory presets across 10 categories (Low End, Keys, Lead, Pad & Atmosphere, Chord Memory, Pluck & Arp, FX & Texture, Sequenced, Drum Kit, Init).
  • Full preset browser with search, category sidebar, tag filters, favourites.
  • User preset save with metadata (name, group, author, description, tags).
  • Import / export individual preset XML files.
  • A/B compare snapshot slots for live tone comparison.

UI & visualization

  • 6-tab navigation: Presets, Synth, Modulation, Effects, Seq/Arp, Setup.
  • Stereo oscilloscope, vectorscope, spectrum analyser, 3D spectrogram, stereo field monitor.
  • Per-VCO inline mix meters, ADSR envelope visualisers, LFO scope.
  • Master L/R VU meter with peak-hold. 12-voice activity LED strip.
  • 11 bundled themes (Breadbin, Synthwave, Workbench, Driftwood, Rabbit, Phosphor, Sleek Dark/Light/Graphite/Paper/Midnight Blue).
  • Global keyboard shortcuts (18 bindings) with help overlay.

Platforms & formats

  • macOS: VST3, AU, Standalone.
  • Windows: VST3, Standalone.
  • Linux: VST3, Standalone.
  • iOS / iPadOS: AUv3, Standalone (with on-device Audio/MIDI settings).