K-One Features:

Over 75 bespoke presets, made in consultation with some of the top music producers in the UK.

30 parameters for complete creative control. All mappable when used as an Auv3 audio unit.

K-One is based around four oscillators - a pulse wave, morphing sine-sawtooth wave, square sub and a noise oscillator.

A smooth, Moog-style resonant low pass filter, which can be modulated with its own envelope as well as via LFO.

5 different effects, including overdrive, delay, reverb and two custom made choruses, which give a deep, richness to the sound.

A non-resonant highpass filter.

Two ADSR envelopes for modulating the amp and filter.

Capable of an uncapped amount of polyphonic voices, or switch to the fat mono mode for basses and leads.

Pitch bend control.

A 127 note on-screen keyboard.

Compatible with Audiobus, Inter-App Audio, AUv3 and external midi control.

What’s New

Version 1.2

Thanks for all the comments and suggestions!
Made a few changes in this update -

Changed the reverb algorithm
Added a volume meter within the audio unit
Smoothed out changes in delay time
Boosted output level

Ratings and Reviews

3.8 out of 5
5 Ratings

5 Ratings

Dj Ed Nine ,


Good synth but the dry oscillators with no fx or editing have clicks when hitting the notes. The sounds of the notes also cut off when you touch the bottom of the keys.

Nitpick Pete ,

Superb retro sound

Excellent emulation of vintage synth. Wishing the onboard delay was more vintage with a smooth speed change, but it is nice that the developer included it. I've only had the app for a few moments but am so impressed with the easy interface and pleasing sound, I just had to comment right away. Blown away by the diverse range of noises the thing can make.
A great start. Anxious to see how the developer continues to refine it with updates.

Developer Response ,

Hi Nitpick Peter! Thanks for the kind words. Funnily enough I was just thinking about changing up the delay so time changes are smoother! Gonna make that change this week. Send me an email with any other suggestions if you’d like. Colin

anickt ,

I like it!

It can get a little wild with some crazy LFO modulation and screeching resonance. But that’s all good and many of the presets are really nice. Having all controls on one screen is nice. The dev is quite responsive and has already implemented some new features. It’s a keeper!


Colin Hallett
81.2 MB

Requires iOS 10.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating


  • Family Sharing

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

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