A browser-based synth using the Web Audio API and HTML.

• Polyphonic
• On-screen keyboard
  • Play by clicking mouse
  • Play by pressing corresponding qwerty keys
  • Drag "handle" to remap qwerty keys around keyboard
• MIDI Keyboard
  • Tested with M-Audio Keystation Mini 32
  • Volume knob will modify whichever parameter has focus
• Oscillators
  • Various wave forms
  • Shift and detune parameters
• Filters
  • Various pass/band types
  • Cutoff frequency parameter
• Amplifier
  • Gain parameter
  • ADSR envelope
• Stereo panning
  • With LFO and envelope
• Parameters
  • Immediately update audio when changed
  • Have linear or exponential mappings for enhanced control, e.g. pitch shift (linear) or frequency cutoff (exp)
  • Can be continuous or discrete, e.g. detune (continuous) or pitch shift (discrete notes)
  • Right click to reset back to initial value
• LFOs
  • Can be synced for improved polyphony
  • Can use standard wave shapes or a random generator
• Import and export patches as JSON files

Access the online version at synthrack.app.

Or download this repository and open index.html in a browser window.

Or download this repository and host it locally: python -m http.server and then open localhost:8000 in your favourite browser.

(Currently only tested in Google Chrome on laptop and Android).

• Add preset patches
• Improve naming of input elements to assist screen readers
• Try reusing oscillators/nodes instead of creating/disposing
  • This doesn't seem necessary now I fixed the memory leak

• Create a noise oscillator
• Add reverb/echo/delay effects etc.
• Add recording/editing functionality
  • Basic sound capture/layering/playback
  • MIDI capture for editing and parameter automation
• Utilise key press velocity from MIDI messages
• Add "hold" button to keep keys pressed while editing
• Add a module mute button
• Add a master volume control
• Add other non-keyboard controllers
  • Use the trackpad like a thermin?
  • Modify incoming audio files
• Consider collapsible sections, i.e. modules or components
• Add wood skins and metal skins etc.