VOOG

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)                               │
├─────────────────────────────────────────────────────────────────┤
│  ┌─┬█┬─┬█┬─┬─┬█┬─┬█┬─┬█┬─┬─┬█┬─┬█┬─┬─┬█┬─┬█┬─┬█┬─┐         │    │
│  │ │█│ │█│ │ │█│ │█│ │█│ │ │█│ │█│ │ │█│ │█│ │█│ │         │    │
│  └─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┘         │    │
└─────────────────────────────────────────────────────────────────┘

Features

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/)

Installation

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 python-tk@3.13

Usage

GUI mode

source .venv/bin/activate
python -m synth --gui

CLI REPL mode

python -m synth

Command-line options

--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

Playing notes

QWERTY keyboard mapping

 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.

Mouse

Click and drag on the virtual keyboard. Drag across keys to glide between notes.

MIDI

Connect any MIDI controller. MIDI CC messages are mapped to synth parameters (cutoff, resonance, envelopes, LFO, etc.).

Rotary knobs

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

Presets

| 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 |

Architecture

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

License

MIT

Voog

Install / Use

README