Kauldron is our warmest sounding, punchiest synth yet! A completely new modeling technology, combined with carefully designed features help you create aggressive synth sounds full of rich analog textures with the fewest knob tweaks. The result is a pure, head-on tone that requires little or no FX or post-production to sound big.

Kauldron pushes every available iOS technology to the max: it is not only fully universal (you can run it natively on your iPad and iPhone), but also an Audio Unit plugin. In fact, it is one of the first fullscreen AUv3 plugins for iOS: with iOS 11 and a compatible DAW, you can enjoy all the great Kauldron features on a nice, big spread.

Kauldron 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 machine learning put to benevolent use!

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.

Powerful arp with both live & program modes; comprehensive MIDI features with effortless MIDI learn; over 900 presets; recording, sharing, IAA, Audiobus 3, Ableton Link — these are just some of the features brewing inside Yonac’s Kauldron.

Selected Specs


• 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


• 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


• AUv3 - use as Audio Unit plugin on iPad & iPhone
• Fullscreen AU mode in compatible DAWs & iOS versions
• Extensive MIDI: MIDI learn, aftertouch, MIDI CC map save/share, KB mapping, program changes & more
• Inter-App Audio
• Audiobus 3
• Ableton Link


• Universal
• 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

Supported Systems

• iOS 10.3 & newer
• iPad Air, iPad Mini 2, iPhone 6, 6 Plus, & newer

Ratings and Reviews

4.6 out of 5
61 Ratings
61 Ratings

Strange behavior, no tech support

I adjusted the filter, including the adsr to something approximating a brass sound, with Osc 2 and 3 off. Then I applied some glide and suddenly the sounds became low volume beeps and there was no way to recover, no reset to default seems to exist, couldn’t find it in the manual either. Exit the app,leave it alone for 24 hr, and it seems fine, glide works the way it should. After reading the manual, which is more of a list than explanation, I got more ambitious and added the other Oscs, fooled around with the second set of adsr and drift and voices, things seemed to work, although the second adsr set is a bit weird.
I had written to Yonac about Kauldron a week before, got no form reply nor tech support. I think I could rate this app four if I thought there was any support. I haven’t tried presets yet but I think I will have to, because the app certainly doesn’t load with your last settings, in fact some knobs are not where you would think they would be and others have stayed where they were. Default behavior and reset are not in the manual, nor is there a a good discussion of all adsr behavior. The filter settings don’t have any meaningful indices that I can see, you don’t know where the resonance is, and there is only one (steep) roll off so you really can’t do brass effectively.

Piano Quartz

A very promising V1, but needs some fixes

Kauldron is the AUv3 do-everything workhorse you've been waiting for. It has a huge sound palette, a straightforward UI, and its AU integration is really well thought-out... but it needs a few fixes.

For one, in BeatMaker and Garage Band, multiple instances of the AU currently all receive MIDI regardless of which track has focus. So you can’t take advantage of the biggest advantage of AU, having multiple instances, yet. Second, there seems to be some kind of bug, maybe a memory leak (at least on the iPad Pro 10.5) where latency gradually increases the longer you use the app and the more patches you switch between.

I’m sure these will be fixed soon, though. Kauldron is a great-sounding synth with a great workflow and I can’t wait for it to become my main iOS synth.

Developer Response

Hello! If you visit our support page on our website, we can help you troubleshoot your issues. It's Cheers! - The Yonac Team


An outstanding offering from a brillant developer

Even at a multiple of the $3.99 into price, Kaudron is a powerhouse of an iOS synth, with a boatload of tone generation, sculpting and performance features. It sounds THICK as a wall made of iron, tons of analog vibe, deep programmability, excellent AU implementation, tons of presets, and did I mention it sounds as thick as a planet made of marzipan, concrete and diamonds, with unlimited musical possibilities? I pretty much buy whatever Yonac releases, but this one has to be the most effortless purchase so far. If you're into iOS music making, don't even hesitate, get it, you will NOT regret it.


Yonac Inc.
37.7 MB
Requires iOS 10.3 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© 2017 Yonac Inc.


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

More By This Developer

You May Also Like