SynthMaster One vs OB
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SynthMaster One
This powerful wavetable synthesizer app offers an intuitive workflow for creating unique sounds. It features a rich library of wavetables, inspiring presets, and a semi-modular architecture for deep sound design. Easily sync data across devices and integrate with DAWs.
- Wavetable synthesis
- Semi-modular architecture
- 650 factory presets
- AUv3 support
- Cross-platform cloud sync
- Real-time modulation feedback
- 32-step arpeggiator/sequencer
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SynthMaster One iOS is KV331 Audio's first full blown universal synth app on iOS platform. It's a powerful wavetable synth with an intuitive workflow. With its simple layout, rich wavetable/waveform content and inspiring factory presets library, designing new sounds with SynthMaster One iOS is a joy. SynthMaster One iOS is feature wise identical to the desktop version except the following: * 16 voice polyphony (32 for the desktop version) * Comes with 650 presets (1250 for the desktop version) FEATURES * Universal App: SynthMaster One is now a universal standalone/AUv3 synth app running on iPhone 7 and above. * 650 Factory Presets: SynthMaster One iOS comes with inspiring factory presets from a world class team of sound designers: Arksun, Aiyn Zahev, BigTone Studios, Brian Transeau, Bluffmunkey, Bulent Biyikoglu, Gercek Dorman, Dejavu Sound, Fragment Audio, Kurt Ader, Mirko Ruta, Nori Ubukata, Rob Lee, Ufuk Kevser, Selcuk Ergen, The Machine, Vandalism Sound, Venus Theory, Vorpalsound and Xenos Soundworks * AUv3: SynthMaster One iOS supports AudioUnits V3, allowing multiple instances to run under supporting DAW apps like GarageBand, Cubasis or Beat Maker. * Files App Integration: Easily import/export presets, waveforms or scales using the common file browser UI (requires iOS 11+). * Real-time Modulation Feedback: See in real-time how modulation sources and targets change. This is a very helpful feature when designing sounds! * Cross Platform Cloud Synchronization: Easily synchronize your SynthMaster One related data across multiple platforms (Windows, MacOS, iPad, iPhone) * Semi-Modular Architecture: For each SynthMaster One instance, there are 2 oscillators with 2 sub oscillators, 2 Filters, 4 ADSR Envelopes, 3 LFOs, a powerful 16 step arpeggiator/sequencer and also 11 different effects that can be inserted on to 6 FX insert slots. The sub oscillators can be connected to the oscillators in 5 different modes which let you use it as a regular sub oscillator or do complex modulations such as ring modulation, amplitude modulation, phase modulation or frequency modulation. * 32 Step Arpeggiator/Sequencer: The arpeggiator in SynthMaster One features classic arpeggiator modes such as Up, Down, UpDown, DownUp, UpDown2, DownUp2, AsPlayed as well as Sequence, Chord and Arpeggiate modes. * Wavetable Synthesis: SynthMaster One implements true wavetable synthesis which opens up new possibilities for sound design. It comes with a rich content library with hundreds of waveforms and wavetables. * Stereo Oscillators with up to 16 voices Unison: Each of the 2 oscillators in SynthMaster One have stereo output, and can have up to 16 voices "unison". Using the "voices", "voices mix", "detune curve", "detune spread", "pan stread", "tone spread" and "phase spread" parameters, each oscillator can generate a rich "supersaw" type sound. * Zero Delay Feedback Filters: All of the 4 filter categories in SynthMaster One are developed using the zero delay feedback filter technology. With advanced filter parameters like input gain, drive, acid, filter nonlinearities and up to 4 times oversampling you can get that "analog" sound from the filters! * Rich Set of Effects: SynthMaster One features 11 different effect types: Distortion, LoFi, Ensemble, Phaser, 6 Band EQ, Compressor, Vocoder, Delay, Chorus, Tremolo, Reverb. * Microtuning: SynthMaster One supports Scala tuning, so tuning can be set either for each preset or globally by loading from a Scala tuning file. SynthMaster One comes with 300+ scales ranging from 5 note equal tempered scales to 12 note alternate tuning scales. * Preset Browser: SynthMaster One features a comprehensive preset browser with separate search criterias for instrument type, preset attributes, music style or preset author. SUPPORTS * All 64-bit iPad devices * AUv3 Audio Unit Extensions * Note-per-channel MIDI controllers (MPE) * Ableton Link * Bluetooth LE MIDI Controllers * AirDrop
OB
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.
- Oberheim OB-X emulation
- Recreates original sound and behavior
- Added enhancements to original design
- Micro random detuning
- Rich and good sound quality
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OB-Xd is based on the Oberheim OB-X. It attempts to recreate its sound and behavior, but as the original was very limited in some important ways, a number of things were added or altered to the original design. OB-Xd was designed to sound as good and as rich as the original. It implements micro random detuning. Also, like many synths of the OB-X's generation, the OB-Xd has no internal effects so its sounds and textures can be greatly enhanced by the use of additional processing like chorus, reverb, delay, etc.
Screenshots
Verdict
The clearest difference is in-app purchases: OB at none against SynthMaster One's 11. OB also leads on chart position (#176 vs unranked). SynthMaster One's advantage is price ($9.99 vs $14.99) and rating (4.7 vs 4.4). On review sentiment, update cadence, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
SynthMaster One costs $9.99 and OB $14.99 up front. SynthMaster One sells 11 one-off in-app purchases. OB asks for nothing beyond the download.
SynthMaster One holds the better App Store score, 4.7 against 4.4. That said, the two scores are not equally well evidenced: SynthMaster One has 743 ratings behind it against 65, so its average is the more settled of the two. Written reviews point the same way: 64% of SynthMaster One's written reviews are positive against 57% of OB's.
Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 14, 2026 and October 11, 2026 respectively.
| Parameter | SynthMaster One | OB |
|---|---|---|
| Price | $9.99 — better | $14.99 |
| Rating | 4.7 (743 ratings) — better | 4.4 (65 ratings) |
| Positive reviews | 63.8% of reviews — better | 57.0% of reviews |
| Number of ratings | 743 — better | 65 |
| Update frequency | Every 2 months | Every 2 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Best chart rank | — | #176 — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 10.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 402 MB | 25 MB |
| Age rating | 4+ | 4+ |
| Developer | KV331 Audio | DiscoDSP LLC |
Customer experience
SynthMaster One
OB
User reviews
SynthMaster One
From 743 App Store ratingsWhat we love
- 🚀 Powerful synth engine
- 👍 Extensive preset library
- 🎨 Versatile sound design capabilities
- 💡 Free desktop version expansions on iPad
- 🎹 Excellent sound quality and tone
Room to improve
- 🐛 Crashes and stability issues
- 🔋 Battery drain in background
- 🤔 Confusing in-app purchase system
- 👎 UI/UX could use improvement
- 🔇 Audio issues and no sound
OB
From 65 App Store ratingsWhat we love
- 🎶 Incredible sound quality
- ✨ Inspiring creative tool
- 🎹 Faithful emulation of classic synth
- 🎛️ Great for programming
- 🎚️ Useful presets
Room to improve
- 🐛 Unusable UI on older devices
- 💻 Poor GUI scaling on iPad Pro
- 🎛️ Controls unresponsive or misaligned
- 📉 Limited functionality without updates
- 🤷♂️ No clear upgrade path
Bugs and requests
SynthMaster One
Reported bugs
4 issues- Stuck notes and MIDI issues
- Preset loading crashes
- Restore purchases not working
- Incompatibility with certain DAWs
Requested features
4 requests- Add custom wavetable support
- Improve MIDI mapping and MPE functionality
- Optimize performance on older devices
- Streamline preset management and browsing
OB
Reported bugs
13 issues- 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)
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- App suspends on iOS 14
- No virtual keyboard in standalone app
- AUv3 crashes when adding second instance
- UI messed up in AU
- Knobs don't line up with display
- Wonky controls
- Programmer page without menu, cannot save/open patches
- LFOing filter cutoff jerky
Requested features
19 requests- Add last/high priority for mono patches
- Increase polyphony to 8 voices
- MIDI Learn functionality
- Preset browser improvements (categories, scrolling)
- Adjustable keyboard size
Show 14 moreShow fewer
- GUI scaling/layout redesign for iPhone
- Skins for GUI
- MIDI keyboard in standalone mode
- Effects
- Preset manager
- Zoom functionality for AUv3 on iPhone
- Fix knob turning bugs
- Add patch select in DAW apps
- GUI color scheme options
- Manual in settings
- Import presets
- Layering sounds (like original OBXa)
- White pinstripes on blue background (cosmetic)
- Mod wheel customization
In-app purchases
SynthMaster One
- BigTone Club Construction Set$4.99
- True Trance Sounds Volume 1$4.99
- Vandalism Future House$4.99
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- NatLife Retrowave Sounds Vol.1$4.99
- Demis Hellen Euphoric Trance$4.99
- Venus Theory Trap Sounds$4.99
- Vandalism Shocking Future Bass$4.99
- NatLife Progressive&Deep Vol.1$4.99
- Bluffmunkey Cinematic Sounds$4.99
- Desktop Presets Upgrade$7.99
- SM One Expansions Bundle$24.99
OB
No in-app purchases







