Bitimbral Polyphonic Synthesizer

VAPoly16 is a virtual analog bitimbral polyphonic synthesizer for iPhone, iPad and Mac. It features 16 voice synthesizer, effects, sequencer and audio visualization tools. It operates as a stand alone or as an AudioUnit Extension (AUv3).  Stand Alone supports Ableton Link, MIDI and audio file export.


The synthesizer consists of two 8 voice synthesizer, which features two oscillators, two ADSR envelopes, resonant high pass and low pass filter and an amplifier per voice. The oscillators features continuously variable wave shape and wide variety of modulation. The filters are modeled on the Sallen-Key filter circuit for classic analog sound.


The Effects include delay, chorus, flanger, reverb, eq and compressor.


The sequencer features piano roll and automation editor to program 16 bar pattern per clip.

Main Features


  • Virtual analog 16 voice bitimbral polyphonic synthesizer


  • 16 bar patterns per clip. Total 16 clips.
  • Parameter automation.

Audio Export

  • Linear PCM format (AIFF, WAV and CAF) and compressed format (AAC)


  • Support iCloud Drive.
  • Support Ableton Link, Bluetooth MIDI, MIDI In / Out.
  • Support Audio Unit Extension (AUv3)
  • Works on iPhone, iPad and Mac.

System Requirements

  • iOS 16.4 or later
  • macOS 13.3 or later
  • For iOS Devices, A10 Fusion or above is recommended.
  • AudioUnit Extension (AUv3) requires host application which support AudioUnit Extension.
  • AudioUnit Extension (AUv3) is supported by Apple Garage Band on iOS and macOS, and Apple Logic on Mac.  For any other DAW, it depends on the application and some of them don’t support AudioUnit Extension (AUv3).
  • *Apple, Mac and GarageBand are trademarks of Apple Inc., registered in the U.S. and other countries.
  • *Ableton and Link are trademarks of Ableton AG.
  • *All products, companies and standard names are trademarks or registered trademarks of their respective holders.
  • * Ableton Link requires Local Area Network connections.

VAPoly16 is available now on the Apple App Store.


User Guide (V1.0.1)



16 voice virtual analog bitimbral polyphonic synthesizer


  • Continuously variable wave shape (triangle, sawtooth, square)
  • Sub: Square, one octave lower (oscillator 1)
  • Pulse width for triangle and square (oscillator 1)
  • Pulse width for square (oscillator 2)
  • Hard Sync (oscillator 1 to oscillator 2)
  • Keyboard on/off (oscillator 2)
  • Low frequency mode (oscillator 2)
  • Tuning +/- 24 semitones
  • Fine tuning +/- 50 cents (oscillator 2)


  • Wave shape: sine, saw, down saw, square, triangle, random
  • Frequency Range:  From 0.04Hz to 42.2Hz
  • Amplitude modulation by ADSR envelope

ADSR Envelope

  • Attack time:    From1ms to 6 sec
  • Decay time:    From 1ms to 10 sec
  • Sustain level:  From 0 to 100%
  • Release time: From 1ms to 10 sec
  • Delay time: From 0ms to 10 sec


  • LFO:   frequency, shape, pulse width, amplitude
  • Env:    frequency, shape, pulse width, LFO amplitude
  • Xmod: frequency and shape
  • Ring:   oscillator 1 output and oscillator 2 output
  • Frequency modulation mode: linear / exponential


  • Resonant High pass filter: -12 dB per octave
  • Resonant Low pass filter: -12 dB per octave
  • Filter envelope: ADSR(Env1/Env2)
  • Frequency modulation by LFO
  • Key Follow
  • Routing: Cascade / Parallel


  • Envelope: ADSR
  • Amplitude modulation by LFO
  • Pan modulation by LFO
  • Mute: On / Off


  • Modulation Wheel
  • Pitch Bend Wheel


  • Type: Up, Down, Up&Down. Random
  • Frequency: From 1 Hz to 20 Hz

Portamento (Glide)

  • Time: From 10 ms to 10 second


  • Loop Length: from 1 bar to 16 bars
  • Clip:               16 clips
  • Tempo:           from 20 BPM to 999 BPM
  • Host Sync:     On and Off


  • Delay, Chorus, Flanger, Reverb, EQ and Compressor

*Appearance and specification of products are subject to change without notice.

Release Note

Version 1.0

  • Initial release

Version 1.0.1

  • Fixed a problem that value of mod wheel when controlled by external device is incorrect.
  • Support iOS 17 / iPadOS 17.
  • Support macOS Sonoma 14.