Analog Synth X


Analog Synth X is a full-featured iPad synthesizer app example by Matthew Fecher and Aure Prochazka built with Swift and AudioKit!

It includes examples of Audiobus, Inter-app audio, and more.

The complete source code is available now as MIT open source. Meaning, you can use it as a learning tool, or even create your own synth app from the code. There's no charge or fee to use the code. Use it as a starting point to create the synth of your dreams!

The code is included AudioKit 3, now available to download. You can find the code for Analog Synth X inside the iOS download package. The code is in the "Examples > AnalogSynthX" folder

To learn more about the features of AudioKit, visit our new site at

Analog Synth X

Synth Features

  • 5-Voice Virtual Analog Synthesizer
  • Audiobus and Inter-app Audio (IAA)
  • Dual VCO-style Oscillators
  • MIDI in for notes
  • Dedicated Sub Oscillator
  • FM Oscillator w/ Mod (Nord Lead style)
  • 4-Pole Vintage Low-Pass Filter (Moog style)
  • Oscillator Morph Knob (Access Virus style)
  • Beautiful Sean Costello Reverb
  • Free-running LFO w/ 4 waveforms
  • Multi-tap (ping-pong) delay
  • ADSR Envelope
  • Detune Oscillators by Semitone & Hz
  • Hold & Mono modes for keyboard
  • Noise generator
  • 8-Bit Crusher

Learning More About the Code

To understand the code quickly, AudioKit 3 has extensive documentation online. Plus, there are over 100 audio playgrounds to get you up to speed on all the audio methods. If you are having trouble, theres even a Google group online for questions regarding AudioKit.

Keep us posted if you build something cool with the code!

Sound Tips for Analog Synth X:

  • You can get a pure Sine wave by (1) turning the Osc Mix to the left (2) turning off VCO1 (3) Turning the FM up!
  • Use the morph knob between square and pulse for basic PWM control.
  • Not getting enough low-end for your liking? Turn down the Rez.
  • Use 2 saws and detune VCO2 for a shimmery vintage Polysynth sound. Slowly open the filter to your taste.
  • The reverse saw LFO (the last wave setting on the LFO) can simulate a basic voltage-controlled note repeat.
  • Keep dry/wet knobs under 50% for a more powerful sound.
  • Turn the ADSR Release down to zero and turn the echo on to hear how the echo taps fire.

Get in the Code:

  • The sub is set to a sine wave for a more powerful bass tone. You can change it to a square if you'd like the synth to have more of a vintage feel. You can also experiment between -12/-24 settings.
  • Try changing the preset knob bounds (minimum/maximum) in the SynthViewController to extremes to play a synth with wild settings!
  • Sub and FM are tracked to the keyboard. Try tracking them to VCO1 for a more accurate Analog synth effect. (i.e. If you detune VCO1, FM & Sub also detune).

Keep us posted on any apps you make with the code, we'd love to hear from you!

New Synth Code

Explore our new free and open-source, synth: AudioKit Synth One.

You can follow @AudiokitMan and @goFecher on Twitter for more tips & updates on AudioKit and other projects.