Bitimbral Monophonic Synthesizer

VAMonoMkII is a virtual analog bitimbral synthesizer for iPhone, iPad and Mac. It features two 8 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 bitimbral synthesizer consists of two 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 Transistor Ladder filter circuit and 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 parameter automation editor to program 16 bar pattern per clip.

Main Features


  • Two virtual analog 8 voice synthesizer with dedicated UI.
  • Two type of Lowpass filter, Transistor Ladder model and Sallen-key model.
  • 8 voices can be used for monophonic or polyphonic.
  • Patch points for modulation.


  • 16 bar patterns per clip. Total 8 clips.
  • Piano Roll and Parameter automation.

Audio Export

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


  • Support MIDI 2.0
  • 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 16.6 or later
  • macOS 13.6 or later
  • For iOS devices, A13 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.

VAMonoMkII is available now on the Apple App Store.


User Guide (V1.0)



Two 8 voice virtual analog bitimbral 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
  • Key Follow: From 100% to 25% (envelope length for highest note)


  • 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, -24 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:               8 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 editing function of clip editor doesn’t work correctly.