Comparison

SynthMaster One vs Kauldron Synthesizer

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

Head to head
About

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.

Highlights
  • Wavetable synthesis
  • Semi-modular architecture
  • 650 factory presets
  • AUv3 support
  • Cross-platform cloud sync
  • Real-time modulation feedback
  • 32-step arpeggiator/sequencer
Read full description

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

About

Kauldron Synthesizer

This app combines classic analog synth warmth with AI-powered sound design. It offers intelligent preset generation, extensive modulation options, and a powerful arpeggiator for creating rich synth textures.

Highlights
  • AI-powered preset generation (SPAWN²)
  • Analog modeling oscillators
  • Extensive modulation matrix
  • Dual XY-pads for control
  • Powerful arpeggiator
  • AUv3 plugin support
  • Over 900 presets
Read full description

Kauldron is where classic warmth meets Artificial Intelligence. One of our toniest and punchiest synths, Kauldron features a completely new analog modeling technology. The full spectrum of rich synth textures is bolstered by the groundbreaking SPAWN intelligent preset generation system that allows new patches to be created at the touch of a button. Abounding with pure hard-hitting tones, Kauldron requires little to no FX or production gimmicks to sound big. Kauldron is designed with modulation and fine dynamic control in mind. The two fully-featured LFOs and the mod envelope combine with a wide variety of MIDI learnable controls to manipulate multiple parameters. Everything is easily set up in a clearly laid out ‘mod matrix.’ The dual XY-pads can be used for controlling modulation or a wide range of synth parameters. MIDI aftertouch can be routed via the matrix for even greater control over expression and tonality. Kauldron also debuts the next generation of our Artificial Intelligence preset creation system, SPAWN². Completely reimagining the groundbreaking SPAWN algorithms in our hugely popular Magellan, the new SPAWN² gives you unprecedented control over generating presets. In the expert mode, you can accomplish anything from subtle ‘variations on a theme’ to bold new sounds. In the basic mode, where Kauldron does all the thinking, you get preset after usable preset with just a touch. This is not simple randomization: it is the power of A.I. put to benevolent use! Kauldron also includes its AUv3 plugin version so that you can seamlessly run multiple instances in your favorite DAW. Powerful arp with both live & program modes; comprehensive MIDI features with effortless MIDI learn; over 900 presets; recording, sharing, these are just some of the features brewing inside Yonac’s Kauldron. Selected specs include, SYNTH • 3 analog modeling oscillators w/ multiple waveforms & true PWM • FM via Osc 2 • Maximizer module with drift, spread & voice count for huge, stereophonic all-synth sounds • New vAnalog filter design w/ ‘dirt’ overload for even warmer, harmonically complex tones • Dedicated filter ADSR envelope • Filter tracking, contour & more • Pink/white noise generator • Osc. phase reset & sync • Retro & modern glide algorithms • Virtual VCA envelope with 2 attack types • Poly/mono operation • Legato mode for buttery smooth passages • Extensive modulation options via the ‘mod matrix’ • 2 LFOs w/ BPM sync, keytracking, trigger mode & more • Assignable mod envelope • 23 mod targets • 11 mod controllers, including aftertouch, velocity & keytracking • 2 XY-Pads for controlling mod targets or synth parameters • Arpeggiator with live & program modes, 11 algorithms, gate, swing, note value, octaving & more • Stereo mod effect with chorus & flanger modes • BPM-syncable stereo delay • Studio quality reverb w/ 7 room types, damping, time & mix • 900+ presets in a wide variety of styles & sounds SPAWN² • Automatic preset generation via artificial intelligence • Generate infinite new, usable presets at the touch of a button • Expert mode lets specify Variation & Autonomy for each major synth module • 3 unique A.I. algorithms • Auto arp programming in any listed scale PRO FEATURES • AUv3 - use as Audio Unit instrument plugin on iPad & iPhone • Fullscreen AU mode • Extensive MIDI: MIDI learn, aftertouch, MIDI CC map save/share, KB mapping, program changes & more APP • iPhone & iPad Compatibility • Powerful YPAT2 preset management system • Classic or ribbon key controller • Ribbon controller: Poly aftertouch into Kauldron • Ribbon controller: Settable musical key & scale • Classic KB: Velocity w/ sensitivity setting • Tapedeck: Record, loop & share • Metronome • Tap BPM

Screenshots

SynthMaster One4 screens
Kauldron Synthesizer4 screens

Verdict

The call

The clearest difference is in-app purchases: Kauldron Synthesizer at none against SynthMaster One's 11. Kauldron Synthesizer also leads on review sentiment (80% vs 64%). SynthMaster One's advantage is update cadence (every 2 months vs every 49 months) and ratings volume (743 vs 136). On price, rating, 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

SynthMaster One costs $9.99 and Kauldron Synthesizer $9.99 up front. SynthMaster One sells 11 one-off in-app purchases. Kauldron Synthesizer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.7 for SynthMaster One against 4.6 for Kauldron Synthesizer. That said, the two scores are not equally well evidenced: SynthMaster One has 743 ratings behind it against 136, so its average is the more settled of the two. Written reviews are what separate them: 64% of SynthMaster One's written reviews are positive against 80% of Kauldron Synthesizer's.

UpkeepUpdate frequency

SynthMaster One ships an update every 2 months, Kauldron Synthesizer every 49 months. The most recent releases landed on September 22, 2026 and September 24, 2026 respectively.

Scorecard6 real differences · 4 level
SynthMaster One versus Kauldron Synthesizer: the parameters behind the verdict, then further details
ParameterSynthMaster OneKauldron Synthesizer
Price$9.99$9.99
Rating4.7 (743 ratings) — better4.6 (136 ratings)
Positive reviews63.8% of reviews79.7% of reviews — better
Number of ratings743 — better136
Update frequencyEvery 2 months — betterEvery 49 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS10.0 — better15.6
Further details — not scored
Size402 MB32 MB
Age rating4+4+
DeveloperKV331 AudioYonac Inc.

Customer experience

SynthMaster One

All ratings743 ratings
Positive92.9%
Neutral2.6%
Negative4.6%
Written reviews207 reviews
Positive63.8%
Neutral10.6%
Negative25.6%

Kauldron Synthesizer

All ratings136 ratings
Positive88.2%
Neutral6.6%
Negative5.1%
Written reviews74 reviews
Positive79.7%
Neutral9.5%
Negative10.8%

User reviews

SynthMaster One

From 743 App Store ratings

What 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

Kauldron Synthesizer

From 136 App Store ratings

What we love

  • ✨ Warm and rich sound
  • 👍 Easy to use interface
  • 💡 Great presets included
  • 🚀 Powerful sound engine
  • 🌟 High quality emulation

Room to improve

  • 🐛 Buggy AUv3 implementation
  • 🔊 Shrill noise issue
  • 🔇 No Bluetooth speaker support
  • ⚠️ Strange behavior/no reset
  • 📉 Lacks oomph/personality

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

Kauldron Synthesizer

Reported bugs

15 issues
  • Oscillators cannot be set to -1 octave
  • Shrill noise
  • No Bluetooth speaker output
  • Fails to reload with Logic projects
  • Cannot load into Logic Pro
Show 10 more
  • Starts and quits on latest iOS
  • AUv3 bug: receives notes regardless of track selection
  • AUv3 implementation flaky, random crashes
  • AUv3: plays all instances simultaneously
  • Bug with Garageband: duplicates patterns
  • MIDI learn functions not saved
  • Sometimes glitchy
  • XY pad movements not recorded as automation
  • CPU killer on iPad 4
  • No function to share sounds

Requested features

11 requests
  • Bring synths/effects to macOS
  • Mac App version
  • More comprehensive FX section (distortion/saturation)
  • MIDI-out for arpeggiator
  • Drum machine, PAD launcher, DAW
Show 6 more
  • Browser download feature
  • Sequencer in Kauldron
  • Effects tool
  • Version history
  • More developer responses/support
  • Dark mode option

In-app purchases

11 purchases

SynthMaster One

One-time11
  • BigTone Club Construction Set$4.99
  • True Trance Sounds Volume 1$4.99
  • Vandalism Future House$4.99
Show 8 more
  • 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
None

Kauldron Synthesizer

No in-app purchases

Questions

Is SynthMaster One free?
SynthMaster One costs $9.99, and also offers in-app purchases.
Is Kauldron Synthesizer free?
Kauldron Synthesizer costs $9.99, with no in-app purchases.
Which has better reviews, SynthMaster One or Kauldron Synthesizer?
SynthMaster One is rated higher. SynthMaster One averages 4.7 out of 5 from 743 ratings, while Kauldron Synthesizer averages 4.6 from 136 ratings.
Do SynthMaster One or Kauldron Synthesizer have ads?
Neither SynthMaster One nor Kauldron Synthesizer shows ads.
Which is updated more often, SynthMaster One or Kauldron Synthesizer?
SynthMaster One ships an update every 2 months, and Kauldron Synthesizer every 49 months. Most recently, SynthMaster One was updated on September 22, 2026 and Kauldron Synthesizer on September 24, 2026.

Other comparisons