subsnake

subsnake is a polyphonic virtual analog subtractive synthesizer, written in python.

what's it do?

well, i'm glad you asked.

• it has 16 voices of polyphony
• it supports midi (input)
• it can save & load patches
• it can record, overdub, play, loop, & save audio

what's in a voice?

• 3 sine, triangle, sawtooth, or pulse oscillators with pitch, detune, level & width controls | 2 algorithms (BLIT, polyBLEP)
• 1 state-variable filter with resonance, saturation & drive | 2 types (canonical Chamberlin, ZDF-solved Chamberlin)
• 2 ADSR envelopes - one for amplitude, one for filter frequency (with bipolar depth control) | .004-4s per stage
• 4 modulators - 2 LFOs, 2 AR envelopes, with dedicated assignable attenuverters for every parameter
  • LFO shapes: sine, triangle, ramp, sawtooth, square, sample & hold
    • 0.01-10Hz w/ controllable phase shift
  • env. modes: attack-release, attack-hold-release, loop (attack-release)
    • .01-1s per stage

there's also a stereo tape delay effect on the master bus (voice output + recorder), and a stereo audio recorder/looper with continuous overdubbing.

what's the midi like?

• it supports device & channel selection, with note-on velocity (linear curve)
• cc's can be added & removed, and freely assigned to control any parameter
  • parameter updates are reflected visually, so the sliders & displays remain in sync with cc's
• gate on/off events use sample-accurate timing (works well with sequencers)

how's the modulation?

• every parameter has a dedicated bipolar modulation control (the small knobs left of each slider)
• right clicking a knob changes the assigned modulator (and color)
  • none (disconnected) -> lfo1 -> lfo2 -> menv1 -> menv2 -> back to none
• left clicking a knob and dragging up/down will increase/decrease the modulation amount
• double clicking any knob will reset the modulation amount to 0.0 (centered)

is there anything else?

• to reset a parameter, double click the parameter display (to the right of each slider)
• the keys A-' are mapped chromatically and can trigger note events (fixed velocity)
  • to shift the pc keyboard octave range up/down, use the +/- keys, respectively
  • you can set the pc keyboard velocity (0-127) from the synth settings panel
• to switch between oscillator types (BLIT/polyBLEP), right click the oscillator title box
• to switch between filter types (Chamberlin/ZDF), right click the filter title box
• the filter & oscillator type selections are saved with the patch (& restored on load)
• the width parameter will have a different effect, depending on the selected shape:
  • sine: crossfades between silence at both extremes (center is full volume)
  • triangle: morphs the waveform from a sawtooth (w≈0.0), through a triangle (w=0.5), to a ramp (w≈1.0)
  • saw: crossfades between a saw & a second (free-running) saw at twice the fundamental (center is full fundamental)
  • pulse: bog-standard through-zero PWM
• each oscillator is paired with a stereo panner, allowing for precise placement (or modulation) across the stereo field
• filter key tracking & oscillator drift can be configured (per patch) via the synth settings menu
• the stereo delay can be made into a pitch-shifting delay (or pseudo-chorus) by modulating the time parameter with an LFO

how can i play it?

• v0.4.1 is the latest build
• click on the version that corresponds to your platform to download the zip, extract, & run! if it doesn't open:
  • on linux: right click the file, go to Properties -> Permissions, and make sure "Allow executing file as program" is checked
  • on macos: you'll need to authorize the app when running it for the first time. go to System Settings -> Privacy & Security, scroll down to the bottom, and choose Open anyway (under Security)
  • on windows: click More info on the smartscreen popup and choose Run anyway
• note: on first load, it may take 1-2 minutes for the initial numba compilation step to complete.
• note: this project is in active development. though I test every build prior to release, you may still encounter bugs.

what else is planned?

• save & auto-restore midi settings (channel, cc's, parameter mappings)
• recorder settings panel:
  • adjustable loop start/end points
  • input level control (currently fixed)
  • playback speed control
• synth settings panel:
  • voice stacking & spread
• oscillators:
  • noise module
  • more algorithms
    • LP-BLIT implementation
    • VOSIM implementation
    • anti-aliased wavetable oscillator
• modulators:
  • make LFOs anti-aliased (for audio-rate mod.)
  • increase max. LFO rate to audio range
  • additional LFO modes:
    • reset phase on gate
    • key pitch tracking (w/ ratio)
• effects:
  • stereo delay
    • add ping pong & dampening parameters
  • stereo chorus
  • algorithmic reverb
  • combine effects into single stack
• isorhythmic pattern generator/sequencer
• Lissajous display mode for scope
• more patches :3