# ButterSynth

> Hybrid 6-oscillator wavetable, FM, and sample-based synthesizer with extensive modulation and effects. (iPhone/iPad app by Arto Vaarala.)

- Source: https://appshunter.io/ios/app/buttersynth/id1497419006 (this page in markdown: same URL + `.md`)
- Developer: [Arto Vaarala](https://appshunter.io/developer/890886114)
- Category: Music, Productivity
- Price: $19.99
- Rating: 4.00/5 from 62 App Store ratings · 57 written reviews indexed
- Age rating: 4+
- Requires: iOS 14.0 · 468 MB
- Languages: American English
- Released: 2023-04-28
- Data updated: 2026-08-30
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/buttersynth/id1497419006/reviews.md

## What is ButterSynth?

ButterSynth is a hybrid 6-oscillator wavetable/FM/sample-based AUV3 and standalone synthesizer with a vast sonic range, from gentle pads to screaming leads and basslines. 
Mix any combination of wavetable, FM, sample and other synthesis engines for one truly massive sound. 
For the more advanced users, you'll love using ButterSynth's thoughtfully designed interface, incredibly powerful modulation matrix, fully-featured internal FX rack, factory waveform and sample libraries, and almost limitless scope for fun, experimentation and sound design. 
For less experienced synth programmers, ButterSynth includes a library of hundreds of ready-to-use presets, sparking your creativity to start making music right away.


Headline features include
- Mix and match any combination of 6 synthesis engines to either emulate your favourite synths of yester-year or build a synth ready for the future. 

- Dual-wavetable engines also feature 9 phase modes, wave folding, and deep unison controls modelled on vintage hardware synths. 

- Built-in wavetable editor gives you the ability to tweak, morph, and hand-draw your own custom wavetables, with each wavetable supporting up to 256 frames. 

- FM engine offers 4 operators with a selection of 12 modulation paths. Each operator can be loaded with any waveform from the factory or user library, and can also self-modulate via the feedback dial. 

- Sample and Granulator engines both let you load samples (either imported or from the factory library) and control precisely how they are chopped, triggered and layered. Both also feature the same powerful unison modes available in the WT engine. 

- Highly configurable 32-slot modulation matrix featuring precise mix/max ranges, self-modulation (via the amount target), plus configurable response curves and layer modes. Simply long-tap any parameter to set it as a Mod destination! 

- Full suite of versatile control sources which includes: 4x MSEG-style looping curve envelopes, 4x LFOs, 4x step sequencers, X/Y pad with motion recording, 8x Macro dials and a powerful arpeggiator inspired by Kirnu Interactive’s Cream. 

- The EFX rack lets you build your own insert effects chain using any combination of the 16 built-in FX modules. Modules available at launch include delay, reverb, distortion, chorus, OTT compression etc. Note  - FX parameters can also be targeted by the mod matrix, unlocking the possibility to program ‘per voice’ modulated effects. 

- All presets, wavetables, samples and other settings are stored in the Files app, making bulk import/export, backup and community sharing quick and easy. 

- All of this is housed in an irresistibly designed 4-tab UI that makes synth programming quick and fun.

## Key features

- Hybrid 6-oscillator synthesis (wavetable, FM, sample)
- Built-in wavetable editor
- FM engine with 4 operators
- Sample and Granulator engines
- 32-slot modulation matrix
- Internal FX rack with 16 modules
- Extensive preset library

## Chart rankings

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

## What do users think of ButterSynth?

Overall sentiment: mixed

**Pros**

- ✨ Deep sound design capabilities
- 🎛️ Versatile modulation matrix
- 🔊 Great sound quality
- 💡 Innovative wavetable generator
- 🌟 Serum-like experience
- 📱 Available on phones/iPads
- 🎹 Excellent for sound design
- 🚀 Powerful and capable synth
- 💯 Top-tier instrument
- 🎶 Amazing workflow and sound
- 💻 Desktop-class plugin on iOS
- 🎨 Beautiful and intuitive UI
- 🎚️ Wide range of filters
- 🎛️ Loads of modulation capabilities
- 💡 Unique random LFO feature
- 🎚️ Good array of effects
- 🎛️ Multiple oscillator types
- 🎚️ FM synthesis included
- 🎛️ Real 4-op FM synthesis
- 🎨 Straightforward interface presentation
- 🎚️ Great filters
- 🎶 Excellent sound
- 💡 Top-notch sound banks/patches
- 🎛️ Highly customizable
- 🎚️ Great for DnB
- 🎛️ Can sound pretty or nasty
- 🎚️ Granular controls
- 🎛️ Deep and great sounding
- 💡 Can recreate popular synths
- 🎚️ Powerful and versatile
- 🎛️ Good selection of presets
- 🎚️ Excellent standalone app
- 🎛️ Amazing wavetable synth
- 🎚️ Good for soundscapes
- 🎛️ Highly recommended

**Cons**

- 📱 Fiddly on small screens
- 🐛 Crashes frequently
- 🐛 Disappears in Cubasis
- 🐛 Spikes CPU usage
- 🐛 Crashes on patch change
- 🐛 No audio on render/freeze
- 🐛 Keyboard doesn't load on iPhone
- 🐛 Audio Unit Extension quit error
- 🐛 Unusable in GarageBand
- 🐛 Preset changes on play
- 🐛 Random crashes in Logic Pro
- 🐛 Patches hang
- 🐛 Limited wavetable selection
- 🐛 Sample module buzz
- 🐛 Simple LFOs
- 🐛 Square wave LFO not square
- 🐛 Step sequencer has glide
- 🐛 Can't save custom presets
- 🐛 No undo in wavetable editor
- 🐛 AUv3 loading issues
- 🐛 Unstable as AUv3
- 🐛 Patches sound different in AUv3
- 🐛 Crashes on iPhone with sequencer
- 🐛 No keyboard in iPhone standalone
- 🐛 Audio degradation in GarageBand
- 🐛 Preset browser closes on selection
- 🐛 Envelope curve is odd
- 🐛 Release envelope ends abruptly
- 🐛 Matrix fiddly with min/max knobs
- 🐛 Missing filter key follow button
- 🐛 Missing sustain pedal support
- 🐛 Missing tunings
- 🐛 Missing master detune
- 🐛 Missing parameter lock
- 🐛 Black borders on screen
- 🐛 Automation not working
- 🐛 No contact option for developer

**Commonly reported bugs**

- App crashing with AUM
- Disappears in Cubasis randomly
- Crashes all the time inside Logic
- Changing a patch spikes CPU to 99%
- Crashes on every patch change
- No audio when rendering or freezing track
- Keyboard doesn't load on iPhone
- iOS18 broke ButterSynth (audio recording issues)
- Failed to load as Auv3
- Crashes as soon as a preset is selected
- Some patches hanging/sounding without input
- CPU spikes to 100% on preset switching
- Audio crackles on preset switching
- Sample module has consistent buzz
- LFOs are extremely simple (no phase offset)
- Square wave LFO is not square (has slew)
- Step sequencer always has glide/slew
- Cannot save custom presets
- No undo function in wave table editor
- AUv3 plugin resets when ButterSynth crashes
- Does not show up as auv3 in Cubasis, AUM, or Audio Evolution
- Crashes regularly even on newest iPad
- Preset changes every time play is pressed
- Not resizing appropriately on smaller screens
- Crashes with unison function in AUM
- White noise on crash with unison
- Sound continues after song stops in GarageBand
- Preset changes on stop, rewind, or play in GarageBand
- Keeps crashing in GarageBand (AUv3)
- Patches in standalone sound different as AUv3
- Crashes when hitting play with arpeggiator/sequencer on iPhone
- No keyboard appears in iPhone standalone mode
- Audio Unit Extension quit error on export
- Lots of crashes in standalone and hosted in AUM
- MIDI not working
- Automation still doesn’t work in Logic Pro
- Random LFO is great for recording sequences
- Preset browser closes each time a new preset is selected
- Works as AUv3 after starting in standalone mode

**Most requested features**

- MPE popup possible on top of the auv3
- Button to hide built-in keyboard
- Buffer size option
- Additional MIDI mappings (e.g., arpeggiator toggle)
- Sustain pedal support
- Longer LFO speed for evolving soundscapes
- Alternative skins/color themes
- Pinable preset browser
- Virtual keyboard to remain active while browser is pinned
- Make app take up whole screen (no black borders)
- Master detune
- Parameter lock
- More presets
- Fix square wave LFO to be truly square
- Fix step sequencer glide/slew for discrete steps
- Undo function in wave table editor
- Filter key follow button
- Adjust envelope curves (especially release)
- Easier way to adjust modulation matrix amount
- Phase distortion inclusion

## Recent user reviews (10 of 57)

All indexed reviews: https://appshunter.io/ios/app/buttersynth/id1497419006/reviews.md

### 5/5 — Updated review years later.

*2026-06-14*

Originally I said that the synth wasn’t great on small screens, but after years of playing around in the iOS music app scene, I’ve come back to this synth as an absolute classic. I’ve gone deep on what’s available here, with two wavetables, with a wavetables generator tool that you can use to tweak harmonics, FM modulation, a wide arrange of filters…. Honestly, amazing. This synth should get much more attention. Whilst it is fiddly to edit on a phone screen, at least it is available on phones and plays presents developed on larger screens (when needed) perfectly. It’s honestly a brilliant balance of functionality and usability and I understand why compromises had to be made to keep it as functional as it is smaller screens. Honestly one of the best, if not the best synths in the iOS/iPadOS toolkit. Really excellent work.

### 1/5 — App crashing

*2026-06-03, version 1.04*

With regular use, I’ve had it crash with AUM. Great app. When it’s not crashing.

### 5/5 — Most complete Pro SoftSynth

*2026-06-01, version 1.04*

Awesome and Functional...mpe popup possible on top of the auv3 As an addition?

### 5/5 — Serum for iPad

*2026-05-16, version 1.04*

This is one rude synth and I’m lovin it bada ba ba baah no joke this is dutty just how I like em

### 4/5 — Amazing, but disappears in Cubasis randomly

*2025-12-07*

Amazing Synth. Great for DnB. Unfortunately one major issue for Cubasis users is that it randomly disappears from time to time leaving entire parts of your track missing. This makes it impossible to work with.

### 3/5 — Abandoned?

*2025-08-03*

This used to be my go-to synth for sound design but without even a bugfix release in over a year I’ve sadly come to the conclusion that it’s abandoned. It crashes all the time inside Logic, and desperately needs a button to hide the built in keyboard.

### 2/5 — Changing a patch spikes my m4 to 99 percent

*2025-05-03, version 1.04*

Changing a patch spikes my m4 to 99 percent.   No way to contact the developer on their website.

### 1/5 — Crash Machine

*2025-04-25, version 1.04*

I have made many great sounds with this app across multiple songs, and in every song this app crashes. Totally unstable and disappointing.

### 1/5 — Crashes on every patch change

*2025-03-30*

It loads but on changing a patch it just disappears

### 1/5 — Everytime i render the track or freeze it Theres no audio

*2025-03-12*

this synth is good but it keeps crashing and bugging out and when I try to freeze or render it to audio it either crash or doesn’t show the audio or it will have like a little bit of the sound and the rest is gone in a bad way. Please fix this bc I use the sample for 808 and it’s good for sound design. Please fix this

Update: it keeps crashing and it’s Annoying theres not even a buffer size  on the synth please fix this please. I like using this synth for samples

## Frequently asked questions about ButterSynth

### What kind of synthesis does ButterSynth offer?

ButterSynth is a hybrid synthesizer that combines multiple synthesis engines. It features wavetable synthesis, FM synthesis, and sample-based synthesis, allowing for a vast sonic range and unique sound design possibilities.

### Can I create my own wavetables in ButterSynth?

Yes, ButterSynth includes a built-in wavetable editor. This allows you to tweak, morph, and hand-draw your own custom wavetables, with each wavetable supporting up to 256 frames for deep customization.

### What are the advanced features for experienced users?

Experienced users will appreciate the thoughtfully designed interface, incredibly powerful 32-slot modulation matrix, fully-featured internal FX rack with 16 modules, and extensive control sources like MSEG envelopes and LFOs. The ability to mix and match synthesis engines also offers limitless scope for sound design.

### Is ButterSynth suitable for beginners?

Yes, ButterSynth includes a library of hundreds of ready-to-use presets designed to spark creativity for less experienced synth programmers. This allows users to start making music right away without needing to learn complex synthesis techniques from scratch.

### How are presets and samples managed?

All presets, wavetables, samples, and other settings are stored in the Files app. This makes bulk import/export, backup, and community sharing quick and easy, facilitating collaboration and organization.

## Version history (last 5 releases)

### 1.04 — 2023-12-08

- Fixed: Note panning issue which occurred at the beginning of the note

### 1.03 — 2023-11-28

- Fixed MIDI learn
- Added new Setting to disable/enable show save preset confirm dialog

### 1.02 — 2023-09-11

- AUv3 improvements. Offline rendering, presets, automation...
- Fixed all known crash bugs
- New presets

### 1.01 — 2023-07-06

- iPhone support
- Lots of crash bugs fixed
- Improved memory handling
- Improved compatibility with Logic Pro for iPad

### 1.0 — 2023-04-28

No release notes.

## Apps similar to ButterSynth

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [BLEASS Megalit](https://appshunter.io/ios/app/bleass-megalit/id1596728818) | 4.6 (32) | $19.99 | Music |
| [Tera Pro](https://appshunter.io/ios/app/tera-pro/id1578464219) | 4.6 (155) | $6.99 | Music |
| [Hilda Synthesizer](https://appshunter.io/ios/app/hilda-synthesizer/id6447191659) | 4.9 (57) | $12.99 | Music |
| [Nambu - AUv3 Plug-in Synth](https://appshunter.io/ios/app/nambu-auv3-plug-in-synth/id1624422460) | 4.8 (48) | $16.00 | Music |
| [TROOPER Synthesizer](https://appshunter.io/ios/app/trooper-synthesizer/id1644005057) | 4.8 (71) | $14.99 | Music |
| [FabFilter Twin 3](https://appshunter.io/ios/app/fabfilter-twin-3/id1671810470) | 4.6 (42) | $24.99 | Music |

## More apps by Arto Vaarala

- [Cream Mobile](https://appshunter.io/ios/app/cream-mobile/id890886111)

All apps by Arto Vaarala: https://appshunter.io/developer/890886114

## Related topics

[buttersynth](https://appshunter.io/ios/topics/buttersynth)

---

*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 2026-08-30.*