Comparison

Kauldron Synthesizer vs ShimmerVerb

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

ShimmerVerb

This app creates massive, lustrous reverbs with parallel pitch shifters for ethereal, shimmering soundscapes. It offers advanced feedback control and performance-oriented features like a "Ribbon" macro and "HotSwitch" for dynamic sound shaping.

Highlights
  • Massive lustrous reverb with parallel pitch shifters
  • Infinitely feedbackable signal for cascading reverbs
  • Adjustable feedback frequencies via cross-over network
  • Playable "Ribbon" performance macro
  • Instant parameter switching with "HotSwitch"
  • "Freeze" button for smeared textures
  • AUv3 plugin and standalone app
Read full description

ShimmerVerb combines a massively lustrous reverb with parallel pitch shifters to add ethereal layers making any signal, well, "shimmer." Oftentimes, producers would achieve the effect by using Eventide pitch shifting hardware such as the H910, H949, or H3000 or other rack mount units in combination with a reverb. This production technique was popularized by Daniel Lanois and Brian Eno on U2's The Unforgettable Fire. Now, this iconic sound has been refined and extended with a modern, unified interface that is great for adding dreamy ambiance to guitars, keys, synths, samples, and vocals. In typical Eventide fashion, features have been added such as the ability to infinitely feedback the signal, resulting in cascading reverbs that smear into oblivion. Feedback can be further fine-tuned by specifying which frequencies are fed back through the low/mid/high cross-over network. ShimmerVerb shines via its playable, performance-based parameters. "The Ribbon" is an easy to program performance macro allowing users to morph between two settings with one control. Desktop users can plug in a MIDI keyboard and gain tactile command over this function via the modulation wheel. Ribbon mappings are great for Feedback swells, moving the Pitch knobs, or changing the Size for a massive detuning result. ShimmerVerb also boasts a HotSwitch for calling up another state of parameters inside the same preset. Use this for changing octaves, turning off/on the pitch shifters, or simply turning the Mix up or down while crafting your performance. Finally, the Freeze button allows you to make smeared textures out of single voices, full pads, or percussive elements resulting in metallic "shimmers." Features: - Unique reverb plug-in with parallel pitch shifters on the reverb tail. - Easily pitch with perfect fourths, fifths, and octaves. - Micropitch tuning available around perfect intervals. - Four octaves of pitch shifting (from two octaves down to two octaves up). - Delay pitched signals up to one second or sync them to your DAW's tempo. - Feedback determines how much delayed signal is fed back into the input of the reverb. - Low, Mid, and High cross-over network determines which frequencies are fed back. - FREEZE holds the current state of the reverb in a smeared texture. - The RIBBON allows for real-time modification of several parameters at once. - HOTSWITCH allows for instant switching between two sets of parameters within one preset. - Available as an Audio Units AUv3 plug-in and Standalone App.

Screenshots

Kauldron Synthesizer4 screens
ShimmerVerb3 screens

Verdict

The call

The clearest difference is update cadence: ShimmerVerb at every 6 weeks against Kauldron Synthesizer's every 49 months. ShimmerVerb also leads on iOS requirement (11.0 vs 15.6). Kauldron Synthesizer's advantage is price ($9.99 vs $14.99) and ratings volume (136 vs 12). On rating, review sentiment, ads and in-app purchases 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 ShimmerVerb $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.6 for Kauldron Synthesizer against 4.6 for ShimmerVerb. That said, the two scores are not equally well evidenced: Kauldron Synthesizer has 136 ratings behind it against 12, so its average is the more settled of the two. Written reviews are what separate them: 80% of Kauldron Synthesizer's written reviews are positive against 78% of ShimmerVerb's.

UpkeepUpdate frequency

Kauldron Synthesizer ships an update every 49 months, ShimmerVerb every 6 weeks. Both last shipped on November 3, 2026.

Scorecard4 real differences · 6 level
Kauldron Synthesizer versus ShimmerVerb: the parameters behind the verdict, then further details
ParameterKauldron SynthesizerShimmerVerb
Price$9.99 — better$14.99
Rating4.6 (136 ratings) — better4.6 (12 ratings)
Positive reviews79.7% of reviews — better77.8% of reviews
Number of ratings136 — better12
Update frequencyEvery 49 monthsEvery 6 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.611.0 — better
Further details — not scored
Size32 MB14 MB
Age rating4+4+
DeveloperYonac Inc.Eventide

Customer experience

Kauldron Synthesizer

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

ShimmerVerb

All ratings12 ratings
Positive83.3%
Neutral8.3%
Negative8.3%
Written reviews9 reviews
Positive77.8%
Neutral22.2%
Negative0.0%

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

ShimmerVerb

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Kauldron Synthesizer

No in-app purchases

None

ShimmerVerb

No in-app purchases

Questions

Is Kauldron Synthesizer free?
Kauldron Synthesizer costs $9.99, with no in-app purchases.
Is ShimmerVerb free?
ShimmerVerb costs $14.99, with no in-app purchases.
Which has better reviews, Kauldron Synthesizer or ShimmerVerb?
Kauldron Synthesizer is rated higher. Kauldron Synthesizer averages 4.6 out of 5 from 136 ratings, while ShimmerVerb averages 4.6 from 12 ratings.
Do Kauldron Synthesizer or ShimmerVerb have ads?
Neither Kauldron Synthesizer nor ShimmerVerb shows ads.
Which is updated more often, Kauldron Synthesizer or ShimmerVerb?
Kauldron Synthesizer ships an update every 49 months, and ShimmerVerb every 6 weeks. Most recently, Kauldron Synthesizer was updated on November 3, 2026 and ShimmerVerb on November 3, 2026.

Other comparisons