KV331 SynthMaster 2 iOS review

Bringing its fully-featured flagship synth to iPad/Phone users, is this breakout version of KV331’s creative powerhouse the master of all?

  • £10
KV331 SynthMaster 2 iOS
(Image: © Future)

MusicRadar Verdict

Brimming with sonic potential, SynthMaster 2 iOS is the solid culmination of one of the best mobile synths around.


  • +

    Awesome modulation effects.

  • +

    Flexible UI options.

  • +

    Perfect for sound design on-the-move.

  • +

    Great value for the price.


  • -

    Steep learning curve.

  • -

    At times hard to control multiple rotaries.

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KV331 SynthMaster 2 iOS: What is it?

SynthMaster One, KV331’s 16-voice semi-modular beauty, first appeared in the App Store in 2018. This ridiculously underpriced monster provided a dazzling array of high-quality wavetables and flexible sound design potential, but undeniably a truly mobile version of the more versatile desktop version of SynthMaster would be a much more appealing prospect. Nevertheless, SynthMaster One has remained a reliable go-to for years.

Now, in 2021, with the desktop SynthMaster being periodically updated and still maintaining its status as a renowned player in the softsynth hierarchy, KV331 Audio has released the iOS successor. This time though, this isn’t any kind of ‘lite’ version. SynthMaster 2 sports all the bells and whistles of its desktop parent. 

Synth-pop master

The main headline here is that KV331 has essentially ported SynthMaster 2.9 – in its feature-packed entirety – to the iPad. So, what are its key attributes? 

Well, first off there’s the robust sound engine, which houses the virtual oscillators, modulators and filters. The app’s synth stages are programmable via a slickly re-tooled, cross-platform UI which also supports the native resolutions of numerous iPad types. 

There are also 1000 top tier presets as standard, designed by such luminaries as Ubukata, NatLife and Yuli Yolo – a notable increase on SynthMaster One’s 500.

KV331 SynthMaster 2 iOS: Performance and verdict

Upon installing the app, you can dive straight into preset land. Navigation through the browser is fluid, and before too long, the sonic magnitude of SynthMaster 2 is revealed. 

Across diverse presets such as the retro-vibed cool of FM Strings MS, the percussive impacts of BAS Aluminium or the dirtied up synth-basses like the ones provided by the BA Chaos Bass preset, it’s clear that this app can contend with the likes of Arturia’s Pigments and the other big boys of synth sound design. 

Also consider...

Waldorf Music Nave

(Image credit: Future)

Waldorf Music Nave
Waldorf’s wavetable app lets users play in a dazzling hybrid wavetable/analogue world. A real contender.

Audiokit Synth One
A sublime – and free – iOS synth with huge sound sculpting scope, but nowhere near the depth.

The primarily rotary controls are pretty straightforward, and you’ll be on familiar ground if you’ve used any of the previous iterations of SynthMaster. The softsynth’s engine is built around its dual-layer oscillators, which can be set to four different wave-generating approaches. 

Basic provides single-cycle waveforms or samples, while Additive allows eight oscillators to be stacked up, resulting in some beefy tones, Wavetable mode allows for more gradual and nuanced waveshape blending, and Vector mode mixes four oscillators in a 3D, spatial audio-leaning way. 

Next up is a supremely detailed raft of modulators and filters which can muddy, detune or hammer your sounds into shape. You can also view your sound-chain with real-time visual feedback, giving the user a better grasp of how sound is being effected – editing in this section is all the more simple, too. The depth here is staggering, inviting you to experiment with each encoder to see how far you can go. 

Insert (effects) here

Further shaping of your unique sounds is achievable using one of SynthMaster 2’s 12 insert effects; these include Delay, Compression, Chorus, Tremolo and the like. Both of its layers have five insert effect slots each, while you can also harness the power of two global effect send busses to see how they sound across every channel. 

The shimmering Chorus effect is particularly noteworthy, especially when you’re using Additive mode to build up bigger synth-constructs.

Playing notes via the keyboard (again, hugely modifiable depending on the type of layout you want) is just as fun as it was in SynthMaster One. The only issue that might get in the way of your enjoyment is making those quick, subtle rotary tweaks as you perform – often they won’t detect that they have been touched, though perhaps this is more a design flaw with the iPad.

It’s clear from early experiments that SynthMaster 2 will be our new go-to for quick synth-idea generation. Every aspect of the already top-notch experience has been refined to complete the story as it always was meant to be – fully featured and mobile.

MusicRadar verdict: Brimming with sonic potential, SynthMaster 2 iOS is the solid culmination of one of the best mobile synths around.

KV331 SynthMaster 2 iOS: The web says

"The developers have done a great job. The sound is as great as on a PC / Mac, but programming sounds is much more fun with touch."
Synth Anatomy

KV331 SynthMaster 2 iOS: Hands-on demos


The Sound Test Room

KV331 SynthMaster 2 iOS: Specifications

  • Runs as a standalone app or AUv3 plugin on iPads with iOS 11 and above. 
  • User interfaces provided for 9.7, 11 and 12.9-inch iPads in 4 different skins (Blue, White, Dark, Proto). Separate interfaces are provided for the AudioUnit plugin as well.
  • Comes with 1,000 factory presets.
  • There's also an IAP Shop which lets users purchase additional sounds.
  • CONTACT: KV331Audio/App Store
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