# OB vs ButterSynth

The clearest difference is price: OB at $14.99 against ButterSynth's $19.99. OB also leads on rating (4.3 vs 4.0). On review sentiment, ratings volume, update cadence and ads there is nothing between them.

OB costs $14.99 and ButterSynth $19.99 up front. Neither carries in-app purchases, so what you see is what you pay.

OB holds the better App Store score, 4.3 against 4.0. Both are backed by a comparable volume of ratings — 64 and 63 respectively. Written reviews complicate that: 57% of OB's written reviews are positive against 59% of ButterSynth's, so the app with the better star average is not the one people write more warmly about.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 24, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | OB | ButterSynth |
| --- | --- | --- |
| Price | **$14.99** | $19.99 |
| Rating | **[4.3 (64 ratings)](https://appshunter.io/ios/app/ob-xd-auv3-synth/id1465262829/reviews)** | [4.0 (63 ratings)](https://appshunter.io/ios/app/buttersynth/id1497419006/reviews) |
| Number of ratings | **64** | 63 |
| Positive reviews | 57.0% of reviews | **59.2% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | **Free** | Paid |
| Size | 25 MB | 468 MB |
| Requires iOS | 15.0 | **14.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [DiscoDSP LLC](https://appshunter.io/developer/1465262828) | [Arto Vaarala](https://appshunter.io/developer/890886114) |

## What reviewers say

### OB

[App page](https://appshunter.io/ios/app/ob-xd-auv3-synth/id1465262829)

This app emulates the classic Oberheim OB-X synthesizer, offering its rich sound and behavior with added enhancements. It focuses on sonic quality and includes micro random detuning for authentic analog warmth. External effects are recommended to further shape its versatile soundscapes.

**Highlights:** Oberheim OB-X emulation, Recreates original sound and behavior, Added enhancements to original design, Micro random detuning, Rich and good sound quality

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- 🎶 Incredible sound quality
- ✨ Inspiring creative tool
- 🎹 Faithful emulation of classic synth
- 🎛️ Great for programming
- 🎚️ Useful presets

**What reviewers complain about**

- 🐛 Unusable UI on older devices
- 💻 Poor GUI scaling on iPad Pro
- 🎛️ Controls unresponsive or misaligned
- 📉 Limited functionality without updates
- 🤷‍♂️ No clear upgrade path

**Reported bugs**

- Crashes in Audiobus
- Cannot use in MIDI section of Audiobus
- Preset browser issues (scrolling, cut off banks)
- Automation bug with cutoff freq
- UI issues on iPad Pro (buttons misaligned, text cut off)

**Requested features**

- Add last/high priority for mono patches
- Increase polyphony to 8 voices
- MIDI Learn functionality
- Preset browser improvements (categories, scrolling)
- Adjustable keyboard size


### ButterSynth

[App page](https://appshunter.io/ios/app/buttersynth/id1497419006)

This powerful synthesizer app offers a hybrid approach, combining wavetable, FM, and sample-based synthesis. Create unique sounds with a vast sonic range, advanced modulation, and a built-in effects rack. It caters to both experienced sound designers and beginners with extensive presets.

**Highlights:** 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

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- ✨ Deep sound design capabilities
- 🎛️ Versatile modulation matrix
- 🔊 Great sound quality
- 💡 Innovative wavetable generator
- 🌟 Serum-like experience

**What reviewers complain about**

- 📱 Fiddly on small screens
- 🐛 Crashes frequently
- 🐛 Disappears in Cubasis
- 🐛 Spikes CPU usage
- 🐛 Crashes on patch change

**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

**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


## Frequently asked questions

### Is OB free?

OB costs $14.99, with no in-app purchases.

### Is ButterSynth free?

ButterSynth costs $19.99, with no in-app purchases.

### Which has better reviews, OB or ButterSynth?

OB is rated higher. OB averages 4.3 out of 5 from 64 ratings, while ButterSynth averages 4.0 from 63 ratings.

### Do OB or ButterSynth have ads?

Neither OB nor ButterSynth shows ads.

### Which is updated more often, OB or ButterSynth?

OB ships an update every 2 months, and ButterSynth every 2 months. Most recently, OB was updated on October 24, 2026 and ButterSynth on October 21, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*