Numerical Audio have consistently brought us high quality the FX iOS apps like Italizer, VC-1, RF-1, RP-1, and also a couple of excellent controller apps (ThereMIDI and MIDIBrute). Now they’ve brought us something new, something very innovative. VOLT is a virtual analog synthesizer designed to create classic synth sounds while emphasising expressive play. The apps comes with full support for multidimensional polyphonic expression (MPE), so VOLT is a great companion to any Seaboard player.

Here’s a quick overview of what’s in the app:

  • Polyphonic Virtual Analog Synthesizer
  • Expressive synth engine with MPE, poly-, channel aftertouch & 2D touch keyboard
  • Built-in stereo effects
  • 100+ fine tuned factory presets
  • Supports ROLI Seaboard controllers out of the box
  • Standalone operation with support for USB audio interfaces, wired, network & bluetooth MIDI
  • Audio Unit v3 Extension
  • Inter App Audio support
  • Audiobus support
  • Ableton Link

Synth Voice:

  • Variable waveshape
  • Variable pulse-width (on all waves)
  • Detunable sub & noise source
  • SEM style state-variable filter
  • LFO per voice
  • Dual ADSR
  • Poly drive (per voice distortion)
  • 8x Polyphony / Unison
  • Detune / Slop
  • Pan Spread
  • Arpeggiator


  • 3x stereo effect units
  • Vintage Chorus
  • Digital Delay (syncable)
  • Epic Reverb


  • MPE MIDI hardware including but not limited to ROLI Seaboard Rise, Seaboard Block, Lightpad Block
  • MPE MIDI software including but not limited to Geoshred, Geoshred Control
  • Regular MIDI keyboards featuring channel or poly aftertouch, pitch- and mod wheels
  • Onscreen 2D Touch Keyboard (supports slide and glide)
  • Plain MIDI Input


  • Factory bank including 100+ expressive presets ready to play out of the box
  • Preset Management with Templates & Categories
  • Shared User Presets between Standalone and AUv3 versions
  • Preset Export


  • Standalone
  • AUv3 Instrument
  • Inter-App Audio Instrument
  • Audiobus Instrument

VOLT is on the app store and costs $8.99: