# VOLT Synth — MIDI Expressive Synthesizer

> Expressive virtual analog synthesizer with MPE support for classic synth sounds. (iPhone/iPad app by Kai Aras.)

- Source: https://appshunter.io/ios/app/volt-synth/id1185984394 (this page in markdown: same URL + `.md`)
- Developer: [Kai Aras](https://appshunter.io/developer/370820899)
- Category: Music
- Price: $7.99 with in-app purchases (on sale, was $19.99)
- Rating: 4.60/5 from 193 App Store ratings · 62 written reviews indexed
- Age rating: 4+
- Requires: iOS 9.0 · 92 MB
- Languages: American English
- Released: 2018-03-29
- Data updated: 2026-08-25
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/volt-synth/id1185984394/reviews.md

## What is VOLT Synth?

VOLT is a virtual analog synthesizer designed to create classic synth sounds while emphasising expressive play. 

With full support for multidimensional polyphonic expression (MPE) - VOLT is a great companion to any Seaboard player.

Overview:
* Polyphonic Virtual Analog Synthesizer
* Expressive synth engine with MPE, poly-, channel aftertouch & 4D touch keyboard
* 5 Keyboard Layouts (Classic, Uniform, String, Scale & Chord)
* Built-in stereo effects 
* 100+ fine tuned factory presets 
* Supports ROLI Seaboard, LinnStrument, Geoshred and others 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

Effects:
* 3x stereo effect units 
* Vintage Chorus
* Digital Delay (syncable)
* Epic Reverb

Input/Expression:
* 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 

Presets:
* 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 & Import via Files.app, Airdrop etc. 
* iCloud Drive Support

Connectivity:
* Standalone 
* AUv3 Instrument
* Inter-App Audio Instrument
* Audiobus Instrument

## Key features

- Virtual analog synthesizer
- Multidimensional Polyphonic Expression (MPE)
- Expressive synth engine
- Multiple keyboard layouts
- Built-in stereo effects
- 100+ factory presets
- Standalone and AUv3 support

## Pricing and in-app purchases

Base price: $7.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Dub Pack | Free | one-time |
| haQ attaQ paQ | Free | one-time |
| Red Sky Lullaby Pack | Free | one-time |


## Chart rankings

- #196 in Top Paid · Music (US App Store)

## What do users think of VOLT Synth?

Overall sentiment: mixed

**Pros**

- 🎶 Great sounds
- ✨ Intuitive UI
-  MPE integration
- 🎵 Expressive
- 💻 Good for travel
- 🎨 Beautiful GUI
- 🚀 Fast development updates
- 💰 Good value for price

**Cons**

- 🐛 Crashing frequently
- ⚠️ Unstable on newer iOS
- 🎛️ Cumbersome sound switching
- 📉 Poor performance
-  unresponsive controls
- 🚫 No sound issues
- ⏳ Slow envelopes
- 🐞 Bugs in AUv3
- ⚫ Black borders on screen

**Commonly reported bugs**

- No MIDI input after 30 seconds
- Crashing when using multiple AU instances
- Presets disappear after iOS 14 update
- Standalone mode broken on recent iOS
- AU3 not working in Cubasis/NanoStudio 2
- Crashes with iCloud Drive for patch storage on iOS 13
- Preset scroller not accessing sounds
- Stability issues on iOS 12
- UI issues in AU mode on iPhone
- No sound after last update
- Presets not loading
- AUv3 UI lacks preset selection slot
- Preset saving crashes app
- Digital readout under controls obscured by finger
- Latched key graphic disappears
- Legato mode doesn't work with aftertouch
- Pitch bend limited to 12 steps
- Global pitch bend setting disappeared

**Most requested features**

- Two fields for sound forward/backward
- New features and sounds for MPE
- Dedicated strings section in presets
- Randomize function for LFOs/envelopes
- Larger fonts in preset display
- Improve envelope snappiness
- Improve modulation routing options

## Recent user reviews (10 of 62)

All indexed reviews: https://appshunter.io/ios/app/volt-synth/id1185984394/reviews.md

### 5/5 — A truly beautiful synthesizer

*2025-01-22*

This developer is an awesome musician, and every one of his inventions are not only unique in their own right, but highly intuitive and extremely useful. This particular GEM is a Godsend. Thank you!!!!!

### 3/5 — WAS Beautiful... no fc's on key touch... latest ios IPhone 12 pro max

*2025-01-18*

See above... can't get it to work anymore, but Will will conter this rating with a fine once usable again... PLEASE UPDATE!!!!!

### 1/5 — Crashing

*2024-08-17*

I haven’t used for while but when I play it now it wont take midi input after about 30 seconds. Controls still work but no audio. Input via hardware keyboard and app in AUM.

### 4/5 — Vieles gut

*2023-12-26*

Aber etwas, dass ich komplett unverständlich finde: warum ist es so schwer, zwei Felder für Sound vorwärts und Sound rückwärts zu integrieren? Ich möchte mich nicht entscheiden müssen, ob ich eine Soundanwahl oder den Synthesizer mit seinen Parametern sehe.

Loben muss ich die App für die Integration von MPE, gut gemacht. Klang stimmt auch. Aber ich spiele ihn einfach viel zu selten, wegen diesem umständlichen Soundwechsel. Kann natürlich sein, das ich einfach zu blond bin, um diese Buttons zu finden, aber ich habe mir Mühe gegeben.

### 1/5 — 👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼👎🏼

*2023-11-13, version 1.4.5*

Not a trustable developer doesn’t fix bugs

### 5/5 — Easy to use and great sounds

*2023-05-06*

Volt is a fun to use synth that makes it easy to create great sounds fast! Love it.

### 1/5 — Does not work on iOS 13. Changing presets does nothing.

*2022-07-03, version 1.4.5*

It used to work OK. Too crashy for real time use. Shockwave has the same issues.

### 1/5 — Pop ups

*2022-05-10, version 1.4.5*

Nags you to rate when you’re playing

### 5/5 — Still the best.

*2022-04-22*

For an “all purpose” synth this thing is my number 1 choice by a large margin. Whenever I just want a voice or pad without wanting to experiment much or design or get into the weeds this is the silver bullet.

### 1/5 — Stand alone doesn’t work

*2022-03-17*

Emailed the developer several times over the last year but apparently he has no interest in fixing it or responding to emails. I have several of his apps and have no trouble with them but I can’t recommend this one.

## Frequently asked questions about VOLT Synth

### What is VOLT Synth?

VOLT Synth is a virtual analog synthesizer application designed to create classic synth sounds with an emphasis on expressive playability. It features a robust synth engine with support for multidimensional polyphonic expression (MPE), making it ideal for users with MPE controllers.

### What are the key features of VOLT Synth?

Key features include a polyphonic virtual analog synth engine with MPE and aftertouch support, five keyboard layouts, built-in stereo effects like chorus, delay, and reverb, over 100 factory presets, and compatibility with various MPE hardware and software. It also supports standalone operation and integration with other music apps.

### How is VOLT Synth monetized?

The application is offered for free, but it includes in-app purchases. This model allows users to explore the core functionality before deciding to purchase additional features or content.

### What devices is VOLT Synth compatible with?

VOLT Synth is designed for mobile devices and supports standalone operation, Audio Unit v3 Extension, Inter App Audio, and Audiobus. It is compatible with MPE MIDI hardware like ROLI Seaboard and LinnStrument, as well as regular MIDI keyboards with aftertouch and pitch/mod wheels.

### What are common use cases for VOLT Synth?

Common use cases include creating expressive synth leads, pads, and basslines for electronic music production. Its MPE support makes it particularly well-suited for dynamic and nuanced performances, especially when paired with compatible controllers like the ROLI Seaboard.

## Version history (last 5 releases)

### 1.4.5 — 2020-10-27

1.4.5 (190)
- Fixed an issue where attempting to connect BLE MIDI devices would cause the app to crash in some cases
- Fixed an issue where effect controls would not work properly
- Fixed an issue where the preset browser was missing when running on an iPhone 11 Pro  Max or iPhone Xs Max

### 1.4.3 — 2020-09-21

1.4.3 (188)
- Added note priority setting 
- Changed scrolling to 2-finger scroll (iPad only) 
- Fixed an issue where touching any ui control could interfere with scrolling 
- Fixed an issue where accessing the preset store could crash the app
- Reverted slider touch behaviour 
- Minor visual tweaks

### 1.4.1 — 2020-09-19

- Fixed an issue where presets would not load properly when running on iOS14
- Fixed an issue with hanging notes
- Improved MPE Implmentation

### 1.4 — 2019-04-11

1.4 (179)
- Added Preset Store with 3 initial preset packs including over 100 fresh patches from Jakob Haq, Stuart Kilbride and the Numerical Team
- Added 2 New Keyboard Layouts: Scale & Chord
- Added support direct preset import from Files.app (Preset Browser -> Import) 
- Added support for fullscreen mode when using the AUv3 
- MIDI CC Mappings can now be set right from the main screen
- MIDI CC Mapping and CC Remote Control is now also available in the AUv3 plugin
- Added Info Mode with built-int descriptions for all controls
- Rate controls now update properly when switching between free running and tempo synced modes 
- Fixed an issue where it wasn't possible to MIDI map parameters with invalid default CC#
- Fixed an issue where scrolling would not work properly when using AUv3 in fullscreen mode
- Fixed an issue where parameter automation and macros would not work properly in NanoStudio 2 (and possible other hosts as well) 
- Fixed an issue where the main UI would not layout properly when running on an 11inch iPad 
- Fixed an issue where applying velocity cause audible artifacts in some cases 
- Fixed an issue where modulating amp level would cause audible artifacts 
- Fixed an issue where applying pan-spread could cause audible artifacts in some cases
- Fixed an issue where applying velocity cause audible artifacts in unison patches
- Fixed an issue where the keyboard settings would not layout properly in some cases
- Fixed an issue where some patches could kill the audio engine when loaded from a specific state 
- Fixed an issue where CC mappings could not be changed once set
- Performance improvements
- Minor visual tweaks

### 1.3.3 — 2018-08-16

- Added support for MIDI Program Change Messages
- Added support for sustain/hold pedals
- Added support for expression pedal (maps to mod wheel)
- Added option to toggle manual scrolling of the main UI (see settings screen)
- Added option to select whether MIDI program changes apply to all presets or just favourites 
- Fixed an issue where MIDI routing via Audiobus/IAA would not work in some cases
- Fixed an issue where some settings would not be be initialized properly when first installing the app 
- Fixed an issue where loading the AU on iPhone would load the wrong orientation in some cases
- Fixed an issue where using traditional MIDI input could cause hanging notes in some rare cases
- Fixed an issue where playing the same note twice using the string layout (or using geoshred) would cause the wrong key to be released upon receiving a note off message
- Minor UI tweaks

## Apps similar to VOLT Synth

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Synth Pro: Analog Synthesizer](https://appshunter.io/ios/app/synth-pro-analog-synthesizer/id1635988723) | 4.6 (544) | Free | Music |
| [Zeeon synth](https://appshunter.io/ios/app/zeeon-synth/id1230960440) | 4.8 (209) | $14.99 | Music |
| [Sunrizer synth](https://appshunter.io/ios/app/sunrizer-synth/id443663267) | 4.7 (183) | $12.99 | Music |
| [AudioKit Synth One Synthesizer](https://appshunter.io/ios/app/audiokit-synth-one-synthesizer/id1371050497) | 4.9 (26,818) | Free | Music |
| [NERD Synth A2x + AUv3](https://appshunter.io/ios/app/nerd-synth-a2x-plus-auv3/id6478898564) | 4.9 (1,342) | $5.99 | Music |
| [BLEASS Omega](https://appshunter.io/ios/app/bleass-omega/id1549511268) | 4.9 (49) | $14.99 | Music |

## More apps by Kai Aras

- [MIDIBrute](https://appshunter.io/ios/app/midibrute/id1010753735)
- [RP-1 Delay](https://appshunter.io/ios/app/rp-1-delay/id1079530569)
- [RF-1 Reverb](https://appshunter.io/ios/app/rf-1-reverb/id1097763239)
- [VC-1 Chorus](https://appshunter.io/ios/app/vc-1-chorus/id1130683829)
- [Italizer](https://appshunter.io/ios/app/italizer/id1133091743)

All apps by Kai Aras: https://appshunter.io/developer/370820899

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-25.*