I posted about AudioKit Synth One a month ago to give you the heads up that the first completely free & open-source professional iOS Synthesizer app in history was on it’s way. Now it’s arrived and, as they promised, it is indeed, completely free. In May I described it as “A big step forward for mobile music”, and I’m sticking to that view. Judging by the initial reactions across the mobile community, lots of other people think it too (check the videos at the end of the post).

The synth has been created by over 100 volunteers from all over the world. The app includes MIDI support (play it with a MIDI keyboard or controller), a sequencer, vintage-inspired analog filters, expressive arpeggiators, warm analog delays, and, over 300 presets to get you started . And of course it is completely open-source.

In fact, you can effectively use the code from Synth One to help you to learn how to build your own synth app or modify Synth One for your own purposes.


  • Hybrid Analog/FM Poly Synthesizer
  • Over 300+ Presets crafted by famous sound designers
  • Audiobus 3 & Inter-app Audio (IAA)
  • Five Oscillators (2 DCO, FM, Sub, Noise)
  • 2 LFOs with over a dozen routing possibilities
  • Vintage-Style 16-Step Sequencer
  • Classic poly arpeggiator
  • MIDI in (Control with a MIDI Keyboard or AudioBus/IAA)
  • Touchable ADSR Envelopes for Amp & Filter
  • FM Oscillator w/ Mod
  • Mono glide and legato
  • Dedicated Sine/Square -12/24 Sub Osc
  • 4-Pole Vintage Low-Pass Filter
  • High-Pass/Band Pass Filters
  • Beautiful Costello Reverb
  • Multi-tap (ping-pong) delay
  • TouchPads
  • Preset & Bank Import/Export & More…

On the roadmap for a future release of Synth One:

  • Ableton Link
  • MPE Support (Play w/ a Roli Seaboard)
  • AUv3 Plug-in support. Use AudioKit Synth One
  • Full Source code will be released soon…

AudioKit Synth One is available for your iPad and is completely free