Comparison

Kauldron Synthesizer vs VAPolyQuad

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

Head to head
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

About

VAPolyQuad

Create rich, analog-style music with this powerful polyphonic synthesizer. Explore a vast array of sound-shaping tools, including multiple oscillators, filters, and effects. Program intricate melodies and rhythms with the built-in sequencer, and seamlessly share projects across your Apple devices.

Highlights
  • Virtual analog polyphonic synthesizer
  • Up to 8 voice polyphony
  • Four oscillators per voice
  • Multiple resonant filters
  • Built-in effects suite
  • 16-bar sequencer with piano roll
  • Audio Unit Extension (AUv3) support
Features
Read full description

VAPolyQuad is a virtual analog polyphonic synthesizer for iPhone, iPad and Mac. It features 8 voice synthesizer, effects, sequencer and audio visualization tools. It operates as a stand alone or as an AudioUnit Extension (AUv3). Stand Alone supports Ableton Link, MIDI and audio file export. Single voice of the synthesizer features four oscillators, two mixers, two resonant high pass filters, two resonant low pass filters, two amplifiers, four ADSR envelopes and four LFOs. The oscillators features continuously variable wave shape and wide variety of modulation. The filters are modeled on the Sallen-Key filter circuit and cascaded OTA filter circuit for classic analog sound. The Effects include delay, chorus, flanger, reverb, eq and compressor. The sequencer features piano roll and parameter automation editor to program 16 bar pattern per clip. Project files can be saved in iCloud Drive, so that the project can be accessed from iPhone, iPad or Mac. - Main Features - Virtual analog polyphonic synthesizer. Maximum 8 voice polyphony. it depends on performance of the device it is running. Four oscillators per voice. Flexible audio signal and control signal routing. Keyboard Control Routing Two type of Lowpass filter, cascaded OTA model and Sallen-key model. Support MIDI 2.0 New User Interface built by SwiftUI for improved performance. Built-in Sequencer. 16 bar patterns per clip. Total 8 clips. Piano Roll and Parameter automation. Support Audio Unit Extension (AUv3) Works on iPhone, iPad and Mac. Support iCloud Drive to share project files between the platforms. Audio Export. Linear PCM format (AIFF, WAV and CAF) and compressed format (AAC) Support Ableton Link, Bluetooth MIDI, MIDI In / Out. 370 Factory Presets - System Requirements - A13 Fusion or above is recommended. AudioUnit Extension (AUv3) requires host application which support AudioUnit Extension. AudioUnit Extension is supported by Apple Logic and Apple Garage Band on iOS and macOS. For any other DAW, it depends on the application and some of them don’t support AudioUnit Extension. Sound may be distorted if CPU of the device doesn't have enough power. If it happens reduce number of voices.

Screenshots

Kauldron Synthesizer4 screens
VAPolyQuad4 screens

Verdict

The call

The clearest difference is review sentiment: Kauldron Synthesizer at 80% against VAPolyQuad's 0%. Kauldron Synthesizer also leads on rating (4.6 vs 4.0) and price ($9.99 vs $14.99). VAPolyQuad's advantage is update cadence (every 22 months vs every 49 months). On ads, in-app purchases, monetization model 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

Kauldron Synthesizer costs $9.99 and VAPolyQuad $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Kauldron Synthesizer holds the better App Store score, 4.6 against 4.0. That said, the two scores are not equally well evidenced: Kauldron Synthesizer has 136 ratings behind it against 5, so its average is the more settled of the two. Written reviews point the same way: 80% of Kauldron Synthesizer's written reviews are positive against 0% of VAPolyQuad's.

UpkeepUpdate frequency

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

Scorecard5 real differences · 5 level
Kauldron Synthesizer versus VAPolyQuad: the parameters behind the verdict, then further details
ParameterKauldron SynthesizerVAPolyQuad
Price$9.99 — better$14.99
Rating4.6 (136 ratings) — better4.0 (5 ratings)
Positive reviews79.7% of reviews — better0.0% of reviews
Number of ratings136 — better5
Update frequencyEvery 49 monthsEvery 22 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, Mac
Requires iOS15.6 — better16.6
Further details — not scored
Size32 MB16 MB
Age rating4+4+
DeveloperYonac Inc.Ryo Togawa

Customer experience

Kauldron Synthesizer

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

VAPolyQuad

All ratings5 ratings
Positive60.0%
Neutral20.0%
Negative20.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

Bugs and requests

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

VAPolyQuad

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Kauldron Synthesizer

No in-app purchases

None

VAPolyQuad

No in-app purchases

Questions

Is Kauldron Synthesizer free?
Kauldron Synthesizer costs $9.99, with no in-app purchases.
Is VAPolyQuad free?
VAPolyQuad costs $14.99, with no in-app purchases.
Which has better reviews, Kauldron Synthesizer or VAPolyQuad?
Kauldron Synthesizer is rated higher. Kauldron Synthesizer averages 4.6 out of 5 from 136 ratings, while VAPolyQuad averages 4.0 from 5 ratings.
Do Kauldron Synthesizer or VAPolyQuad have ads?
Neither Kauldron Synthesizer nor VAPolyQuad shows ads.
Which is updated more often, Kauldron Synthesizer or VAPolyQuad?
Kauldron Synthesizer ships an update every 49 months, and VAPolyQuad every 22 months. Most recently, Kauldron Synthesizer was updated on September 24, 2026 and VAPolyQuad on September 22, 2026.

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