Comparison

Mellowsound vs SynthMaster One for iPhone

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

Head to head
About

Mellowsound

Experience the iconic sounds of a 1960s keyboard sampler with this app. It offers professional audio quality, allowing you to play vintage orchestra sounds on your device. Customize your sound with various effects and recording options.

Highlights
  • Authentic Mellotron emulation
  • Professional 16-bit/44.1Khz audio
  • Photo-realistic user interface
  • Blend mode for two instruments
  • MIDI and Audio Unit support
  • In-app purchases for more instruments and FX
Features
Read full description

Play the iconic Mellotron keyboard sampler heard on The Beatles, Radiohead and King Crimson records — now on your iPhone, iPad & Mac. Mellowsound is built from real recordings of our own Mellotron M400, sampled note by note across all instrument tapes. Every sound is authentic, every detail is preserved. Professional audio quality — 16bit / 44.1kHz Photo-realistic vintage interface AUv3 Audio Unit — plug into any DAW or AUM FREE VERSION includes: • 3 instruments: Flute, Clarinet & Sax • Blend mode: play two instruments simultaneously • Full Mixer, Metronome • MIDI & MIDI Mapping • AudioBus & Inter-App Audio (iOS) FULL VERSION (IAP) includes: • 18 Mellotron instruments: Strings, Piano, Flute, Guitar, Vibraphone and more • User Presets • ADSR Envelope • 6 FX: Tube Amp, Tremolo, Chorus, Pitch-shifter, Delay & Reverb • Live Recording CHAMBERLIN PACK (IAP) includes: • 18 additional instruments: Brass, Pizzicato Violins, Cello, Harpsichord and more Questions or feedback? We'd love to hear from you: contact@fingerlab.net Stay tuned! The Fingerlab Team

About

SynthMaster One for iPhone

This powerful wavetable synthesizer app offers an intuitive workflow for creating new sounds. It features a rich library of wavetables, inspiring factory presets, and real-time modulation feedback for sound design.

Highlights
  • Wavetable synthesis
  • 300 factory presets
  • AUv3 support
  • Files App integration
  • Real-time modulation feedback
  • Semi-modular architecture
  • 32-step arpeggiator/sequencer
Read full description

SynthMaster One for iPhone is KV331 Audio's first full blown synth app for iPhone. 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 for iPhone is a joy. SynthMaster One for iPhone is feature wise identical to the desktop version except the following: * 8 voice polyphony (32 for the desktop version) * Comes with 300 presets (1250 for the desktop version) FEATURES * 300 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 * Interapp Audio and AudioBus * Bluetooth LE MIDI Controllers * AirDrop

Screenshots

Mellowsound4 screens
SynthMaster One for iPhone4 screens

Verdict

The call

The clearest difference is rating: SynthMaster One for iPhone at 4.7 against Mellowsound's 4.3. SynthMaster One for iPhone also leads on iOS requirement (10.0 vs 15.6). Mellowsound's advantage is device support (4 vs 2). On price, review sentiment, ratings volume and update cadence 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

Both are free to download. Mellowsound sells 2 one-off in-app purchases and SynthMaster One for iPhone sells 10 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

SynthMaster One for iPhone holds the better App Store score, 4.7 against 4.3. Both are backed by a comparable volume of ratings — 237 and 335 respectively. Written reviews point the same way: 60% of Mellowsound's written reviews are positive against 66% of SynthMaster One for iPhone's.

UpkeepUpdate frequency

Mellowsound ships an update every 4 weeks, SynthMaster One for iPhone every 2 months. The most recent releases landed on November 4, 2026 and November 3, 2026 respectively.

Scorecard3 real differences · 7 level
Mellowsound versus SynthMaster One for iPhone: the parameters behind the verdict, then further details
ParameterMellowsoundSynthMaster One for iPhone
PriceFreeFree
Rating4.3 (237 ratings)4.7 (335 ratings) — better
Positive reviews60.5% of reviews66.0% of reviews — better
Number of ratings237335 — better
Update frequencyEvery 4 weeks — betterEvery 2 months
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPod, Mac — betteriPhone, iPod
Requires iOS15.610.0 — better
Further details — not scored
Size899 MB297 MB
Age rating4+4+
DeveloperFingerlabKV331 Audio

Customer experience

Mellowsound

All ratings237 ratings
Positive83.5%
Neutral3.0%
Negative13.5%
Written reviews177 reviews
Positive60.5%
Neutral11.9%
Negative27.7%

SynthMaster One for iPhone

All ratings331 ratings
Positive94.9%
Neutral2.1%
Negative3.0%
Written reviews50 reviews
Positive66.0%
Neutral6.0%
Negative28.0%

User reviews

Mellowsound

From 237 App Store ratings

What we love

  • 🎹 Authentic Mellotron sounds
  • 🔊 Great sound quality
  • 🎨 Nice visual design
  • 💸 Good value for money
  • 🔌 Integrates well with other apps

Room to improve

  • 🔇 Limited free version
  • 🔒 Paywall for full functionality
  • 🎹 Keyboard range limited to 3 octaves
  • 🐛 Crashes and stability issues
  • 🔋 High battery drain

SynthMaster One for iPhone

From 335 App Store ratings

What we love

  • ✨ Excellent sound quality
  • 🤩 Incredible features for free
  • 👍 Easy to use interface
  • 🎛️ Versatile sound design capabilities
  • 🎵 Great for GarageBand integration

Room to improve

  • 🐛 Frequent crashes
  • 🔌 Issues with GarageBand integration
  • 💸 In-app purchase problems
  • 🔄 Presets not saving
  • 📉 App appears abandoned

Bugs and requests

Mellowsound

Reported bugs

3 issues
  • Incompatibility with some iOS versions and devices
  • Issues with Inter-App Audio and AUv3 functionality
  • Keyboard not responsive or disappearing

Requested features

5 requests
  • Ability to blend/layer multiple instruments
  • Expanded sound library with more Mellotron presets
  • Sustain pedal support
  • MIDI channel selection
  • Improved performance in DAWs

SynthMaster One for iPhone

Reported bugs

10 issues
  • App crashes when loading saved presets
  • App crashes when setting default sound
  • AUv3 option disappears in GarageBand
  • Inability to reload user patches without crashing
  • Inability to purchase certain IAP packs
Show 5 more
  • Cells don't save, revert to first synth
  • App doesn't function or open in GarageBand
  • Every note is 1 note or lower
  • GUI is cut off on iPhone SE
  • IAA not loading in FL mobile

Requested features

10 requests
  • Fix in-app purchase issues
  • Improve GarageBand AUv3 stability
  • Enable saving of custom presets
  • Address crashing when loading presets
  • Fix note pitch issues
Show 5 more
  • Ensure app is not abandonware
  • Improve UI scaling on smaller screens
  • Fix wavetable scrolling issues
  • Make IAA work properly
  • Allow recording of music

In-app purchases

2 purchases

Mellowsound

One-time2
  • Chamberlin Instruments Pack$8.99
  • Full Version$9.99
10 purchases

SynthMaster One for iPhone

One-time10
  • BigTone Club Construction Set$4.99
  • True Trance Sounds Volume 1$4.99
  • Vandalism Future House$4.99
Show 7 more
  • NatLife Retrowave Sounds Vol.1$4.99
  • Demis Hellen Euphoric Trance$4.99
  • NatLife Progressive&Deep Vol.1$4.99
  • Vandalism Shocking Future Bass$4.99
  • Venus Theory Trap Sounds$4.99
  • Desktop Presets Upgrade$9.99
  • SM One Expansions Bundle$24.99

Questions

Is Mellowsound free?
Mellowsound is free to download, with in-app purchases available.
Is SynthMaster One for iPhone free?
SynthMaster One for iPhone is free to download, with in-app purchases available.
Which has better reviews, Mellowsound or SynthMaster One for iPhone?
SynthMaster One for iPhone is rated higher. Mellowsound averages 4.3 out of 5 from 237 ratings, while SynthMaster One for iPhone averages 4.7 from 335 ratings.
Do Mellowsound or SynthMaster One for iPhone have ads?
Neither Mellowsound nor SynthMaster One for iPhone shows ads.
Which is updated more often, Mellowsound or SynthMaster One for iPhone?
Mellowsound ships an update every 4 weeks, and SynthMaster One for iPhone every 2 months. Most recently, Mellowsound was updated on November 4, 2026 and SynthMaster One for iPhone on November 3, 2026.

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