Virtual Analog Synthesizer — a Moog-style polyphonic synthesizer built in Python with a tkinter GUI inspired by the Subsequent 37.
┌─────────────────────────────────────────────────────────────────┐
│ VOOG VIRTUAL ANALOG SYNTHESIZER │
├─────────────────────────────────────────────────────────────────┤
│ OSC 1 OSC 2 OSC 3 NOISE │
│ (Oct)(Semi) (Oct)(Semi) (Oct)(Semi) (Lvl) │
│ (Det)(Lvl) (Det)(Lvl) (Det)(Lvl) │
├─────────────────────────────────────────────────────────────────┤
│ FILTER FILTER ENV AMP ENV LFO │
│ (Cut)(Res) (A)(D) (A)(D) (Rate)(Depth) │
│ (Env)(Key) (S)(R) (S)(R) │
├─────────────────────────────────────────────────────────────────┤
│ ┌─┬█┬─┬█┬─┬─┬█┬─┬█┬─┬█┬─┬─┬█┬─┬█┬─┬─┬█┬─┬█┬─┬█┬─┐ │ │
│ │ │█│ │█│ │ │█│ │█│ │█│ │ │█│ │█│ │ │█│ │█│ │█│ │ │ │
│ └─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┘ │ │
└─────────────────────────────────────────────────────────────────┘
- 3 oscillators with sine, saw, square, and triangle waveforms
- Moog ladder filter (24dB/oct) with resonance and envelope modulation
- Dual ADSR envelopes for amplitude and filter
- LFO with 4 waveforms and 3 modulation destinations (filter, pitch, amp)
- Glide/portamento with off, always, and legato modes
- Noise generator (white/pink)
- 4 multitimbral channels, 8-voice polyphony each
- 19 built-in presets from deep sub basses to screaming leads
- Rotary knob GUI with Subsequent 37-inspired dark theme
- Virtual keyboard — mouse click/drag + QWERTY PC keyboard input
- MIDI input support (optional, graceful fallback)
- Patch save/load system (
~/.synth_patches/)
Requires Python 3.13+ with tkinter.
# Clone
git clone https://github.com/gpasquero/voog.git
cd voog
# Create virtual environment
python3.13 -m venv .venv
source .venv/bin/activate
# Install dependencies
pip install numpy sounddevice
# Optional: MIDI support
pip install mido python-rtmidi
# macOS only: install tkinter if needed
brew install [email protected]source .venv/bin/activate
python -m synth --gui--gui Launch graphical interface
--patch NAME Load a preset by name (e.g. "Bass Voog")
--midi-port P Connect to a specific MIDI port
--no-midi Start without MIDI input
--list-midi List available MIDI ports and exit
W E T Y U O P ← black keys (sharps)
A S D F G H J K L ← white keys
C D E F G A B C D
Hold a key to sustain — key repeat is filtered so notes don't re-trigger.
Click and drag on the virtual keyboard. Drag across keys to glide between notes.
Connect any MIDI controller. MIDI CC messages are mapped to synth parameters (cutoff, resonance, envelopes, LFO, etc.).
All synth parameters use rotary knob controls:
- Drag vertically on any knob to change its value (up = increase)
- Scroll wheel for fine adjustment
- The amber arc shows the current value position
| Preset | Description |
|---|---|
| Init | Default starting patch |
| Bass Voog | Fat detuned saw bass with filter envelope |
| Lead Saw | Aggressive dual-saw lead with legato glide |
| Pad Strings | Warm evolving pad with slow filter LFO |
| Sub Thunder | Deep sub bass with square wave foundation |
| Acid Squelch | High-resonance filter sweep, 303-style |
| Funky Pluck | Snappy percussive hit, fast decay |
| Screaming Lead | Bright resonant lead with vibrato and glide |
| Warm Brass | Square/saw mix with medium attack |
| Dark Drone | Detuned low saws with slow LFO sweep |
| Perc Hit | Noise burst with ultra-short envelope |
| Vintage Keys | Triangle/square electric piano tone |
| Wobble Bass | LFO-driven filter modulation |
| Trance Lead | Wide-detuned triple saw with pitch vibrato |
| Fat Unison | Three saws spread ±25 cents |
| Reso Sweep | Near self-oscillating filter with long decay |
| Fifth Stab | Power fifth interval, short punch |
| Glass Bell | Sine harmonics with long crystalline release |
| Noise Sweep | Filtered noise with resonant LFO, sci-fi |
synth/
├── dsp/ # Signal processing modules
│ ├── oscillator # Wavetable synthesis (sine, saw, square, triangle)
│ ├── filter # Moog ladder filter (24dB/oct, Huovilainen model)
│ ├── envelope # ADSR envelope generator
│ ├── lfo # Low-frequency oscillator
│ ├── glide # Pitch portamento
│ └── noise # White/pink noise generator
├── engine/ # Audio engine
│ ├── audio_engine # Master engine, sounddevice output, MIDI routing
│ ├── channel # Multitimbral channel (patch + voice allocator)
│ ├── voice # Single voice (oscillators + filter + envelopes)
│ └── voice_allocator # Polyphonic allocation with voice stealing
├── gui/ # Graphical interface
│ └── app # tkinter GUI with rotary knobs and virtual keyboard
├── midi/ # MIDI support
│ ├── midi_input # MIDI port listener (mido/rtmidi)
│ ├── midi_router # Message routing
│ └── cc_map # CC-to-parameter mapping
├── patch/ # Patch system
│ ├── patch # Patch data structure
│ ├── patch_manager # Save/load to disk
│ └── default_patches # 19 built-in presets
└── cli/ # Command-line interface
└── repl # Interactive REPL
MIT