Comparison

ARP ODYSSEi vs ButterSynth

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

ARP ODYSSEi

Experience the iconic ARP analog synthesizer sound on your mobile device. This app faithfully reproduces the classic hardware with enhanced features like polyphony and built-in effects. Explore new sonic possibilities with its advanced arpeggiator and optional design revisions.

Highlights
  • Faithful circuit modeling of ARP ODYSSEY
  • Polyphony and chord playing
  • Programmable step sequencer arpeggiator
  • Built-in effects
  • Optional design revisions (Rev1, Rev2, Rev3)
  • Integration with KORG Gadget
Features
Read full description

The legendary ARP sound, exquisitely reproduced in software. ARP ODYSSEi - A mobile analog synthesizer for iOS. The ARP Odyssey of 1972 has earned an unshakable position as a classic analog synthesizer. In 2015, KORG produced the ARP ODYSSEY, a complete reproduction of the original. The ARP genes that shook the worldwide music scene are being passed on, and its history continues. The next platform for the ARP ODYSSEY is iOS. We want the unforgettable ARP sound to be easily available on a device that as many as possible of today's players can obtain; this resulted in the "ARP ODYSSEi" app for iPad / iPhone. Based on the revived ARP ODYSSEY, we used KORG's proprietary CMT circuit modeling technology to reproduce the analog feeling and sound of the original as closely as possible. We've also given it numerous enhancements that are possible only with software, such as long-awaited polyphony and built-in effects. The real analog ARP ODYSSEY, and now the uniquely evolved ARP ODYSSEi, brings the universal fascination and inimitable sound to every device. * Due to differences in CPU speed of iPads / iPhones, iPad 3rd gen/2/iPad mini/iPhone 4s are not supported, only iPad Air/iPhone 5s or later is recommended. [ Features ] - Faithfully models the circuit of the ARP ODYSSEY: The circuitry has been reproduced using KORG's proprietary CMT (Component Modeling Technology), developed over the years starting with the KORG Legacy Collection. - New functions to create all-new ARP sounds: Added a voice assign mode that allows you to play chords, an arpeggiator that can be programmed in detail like a step sequencer, and effects that can transform the sound in diverse ways. - Get all three of the sought-after revisions: In addition to the standard design of the Rev3 with its black panel and orange silk-screening, you can optionally obtain the white-paneled Rev1 and the black-paneled gold silk-screened Rev2 designs, together with fifty new preset sounds that take advantage of the distinctive filters of those models. - Produce music together with KORG Gadget: ARP ODYSSEi can be used in conjunction with the "KORG Gadget" music production DAW app that has won numerous awards around the world. If both apps are installed, it can be used as the "Lexington" gadget inside the KORG Gadget app. More info at korg.com

About

ButterSynth

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
Read full description

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.

Screenshots

ARP ODYSSEi4 screens
ButterSynth4 screens

Verdict

The call

The clearest difference is price: ButterSynth at $19.99 against ARP ODYSSEi's $29.99. ButterSynth also leads on in-app purchases (none vs 2) and update cadence (every 2 months vs every 8 months). ARP ODYSSEi's advantage is rating (4.6 vs 4.0) and ratings volume (332 vs 63). On review sentiment, 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

CostPrice · In-app purchases · Ads · Monetization

ARP ODYSSEi costs $29.99 and ButterSynth $19.99 up front. ARP ODYSSEi sells 2 one-off in-app purchases. ButterSynth asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

ARP ODYSSEi holds the better App Store score, 4.6 against 4.0. That said, the two scores are not equally well evidenced: ARP ODYSSEi has 332 ratings behind it against 63, so its average is the more settled of the two. Written reviews point the same way: 65% of ARP ODYSSEi's written reviews are positive against 59% of ButterSynth's.

UpkeepUpdate frequency

ARP ODYSSEi ships an update every 8 months, ButterSynth every 2 months. The most recent releases landed on October 17, 2026 and October 16, 2026 respectively.

Scorecard7 real differences · 3 level
ARP ODYSSEi versus ButterSynth: the parameters behind the verdict, then further details
ParameterARP ODYSSEiButterSynth
Price$29.99$19.99 — better
Rating4.6 (332 ratings) — better4.0 (63 ratings)
Positive reviews64.9% of reviews — better59.2% of reviews
Number of ratings332 — better63
Update frequencyEvery 8 monthsEvery 2 months — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS9.3 — better14.0
Further details — not scored
Size222 MB468 MB
Age rating4+4+
DeveloperKORG INC.Arto Vaarala

Customer experience

ARP ODYSSEi

All ratings332 ratings
Positive90.1%
Neutral3.9%
Negative6.0%
Written reviews251 reviews
Positive64.9%
Neutral12.0%
Negative23.1%

ButterSynth

All ratings63 ratings
Positive73.0%
Neutral7.9%
Negative19.0%
Written reviews71 reviews
Positive59.2%
Neutral11.3%
Negative29.6%

User reviews

ARP ODYSSEi

From 332 App Store ratings

What we love

  • 🎨 Faithful recreation of the original ARP Odyssey
  • 👍 Great sound quality and accurate emulation
  • 🎹 Polyphonic and duophonic capabilities
  • 🔊 Impressive built-in effects and sequencer
  • 💻 Works well as a standalone app and within Gadget

Room to improve

  • 🔧 Lack of MIDI implementation (no program change, MIDI learn)
  • 🔀 Issues with tuning and pitch tracking, especially in Gadget
  • 🔒 No AUv3 support, limiting integration with other apps
  • 📱 Small controls and interface can be difficult on smaller devices
  • 🔋 CPU-intensive, causing performance issues on some devices

ButterSynth

From 63 App Store ratings

What we love

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

Room to improve

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

Bugs and requests

ARP ODYSSEi

Reported bugs

3 issues
  • Crashes when trying to import user presets
  • Disappearing sound issues
  • Arpeggiator not working correctly within Gadget

Requested features

5 requests
  • Add AUv3 support for better DAW integration
  • Implement MIDI learn and program change functionality
  • Improve tuning and pitch tracking, especially in Gadget
  • Optimize performance and reduce CPU usage
  • Provide larger UI controls and better support for larger iPad screens

ButterSynth

Reported bugs

39 issues
  • 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
Show 34 more
  • 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

Requested features

20 requests
  • 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
Show 15 more
  • 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

In-app purchases

2 purchases

ARP ODYSSEi

One-time2
  • Odyssey Rev1$4.99
  • Odyssey Rev2$4.99
None

ButterSynth

No in-app purchases

Questions

Is ARP ODYSSEi free?
ARP ODYSSEi costs $29.99, and also offers in-app purchases.
Is ButterSynth free?
ButterSynth costs $19.99, with no in-app purchases.
Which has better reviews, ARP ODYSSEi or ButterSynth?
ARP ODYSSEi is rated higher. ARP ODYSSEi averages 4.6 out of 5 from 332 ratings, while ButterSynth averages 4.0 from 63 ratings.
Do ARP ODYSSEi or ButterSynth have ads?
Neither ARP ODYSSEi nor ButterSynth shows ads.
Which is updated more often, ARP ODYSSEi or ButterSynth?
ARP ODYSSEi ships an update every 8 months, and ButterSynth every 2 months. Most recently, ARP ODYSSEi was updated on October 17, 2026 and ButterSynth on October 16, 2026.

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