Spectrum is a collection of Audio Unit ports of popular eurorack synthesizer modules.

To use Spectrum, load the Audio Units in your DAW or AU host of choice, like Audiobus, GarageBand or AUM. The app itself makes no sound.

Included are:

Spectrum - Multi-mode 8-voice polyphonic oscillator featuring 14 high quality oscillator algorithms

Modal - Modal synthesis. Bowed, Blowed, and Struck sounds through a 64-band resonator. Also included as an effect.

Resonator - 7 beautiful string generation algorithms. Also included as an effect

Granular - Granular sampler, looper, pitch shifter, reverb effect.

Each audiounit also features:
- modulation LFO
- modulation ADSR envelope
- XY touchpad (except on Modal)
- 2-source modulation matrix allowing for complex and evolving patches.
- MIDI CC control of parameters
- Loadable as an AudioUnit effect (except Spectrum)

Spectrum contains DSP code provided under the MIT open source license by Mutable Instruments.

What’s New

Version 0.3

FIXED in 0.3:
- resonator and modal instruments work again in garageband
- added short names
- XY pad modulation from MIDI or AU updates GUI
- MIDI CC list updated
- volume modulation is interpolated, and now works in clouds (for example modulating env -> level)

Ratings and Reviews

5.0 out of 5
58 Ratings

58 Ratings

jellyfish_eats_hamburger? ,

I rate it ten stars out of five.

Absolutely amazing piece of software for free. It’s so easy to use and yet so flexible!- I’m using it not only for music but for sound design for my short films too. I hope the dev charges for it soon because they deserve some cash for the work they put into this and how much better they’re making everyone’s lives. Thanks a million and looking forward to booting up my iPad and making some more music!! :D

Thirdnail ,

Wow! Seriously I’m pretty peeved!

Let me get this straight, in the App Store at this very moment, apps similar to this app, sit next to Spectrum and has a price of well over $9.99 and doesn’t do HALF of what this does?
Honestly I’m a bit p*ssed off at these other developers trying to charge so much, now that I see this app for free!
Well done developer, I hope we ALL donate to your developers and to your app.

Joe Salyers ,

Very Cool for Live Performance

I used this bundle this weekend in my live iPad keyboard rig along with AUM and it gave me some very interesting cool sounds that worked perfectly. Great for bending a stretching sounds at the touch of your hand. I hope there will be more of these tools in the future and with iPad OS right around the corner the iPad music community is about to explode with new users and developers. 5 stars!


Thomas Burns
12.4 MB

Requires iOS 11.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© 2019 Tom Burns


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