Phosphor 3 4+

Vintage Digital Synthesizer

Audio Damage, Inc.

    • 4.5 • 14 Ratings
    • $5.99

iPad Screenshots


Phosphor 3 is the latest version of our Phosphor series of vintage digital synthesizers.

Phosphor is a clone of the alphaSyntauri, one of the first relatively inexpensive digital synthesizers, that ran on the Apple II. Phosphor is a faithful recreation of the alphaSyntauri's additive synthesis engine, and can accurately recreate the sound of this classic and groundbreaking synth.

The Phosphor 3 update brings MPE, tuning tables, extensive modulation, a new preset manager, and an all-new reactive UI to the plugin.

Featuring two additive oscillators (with the original 16 partial complement of the alphaSyntauri, or optionally with 32 or 64 partials), each with its own amp envelope, Phosphor's topology closely follows the alphaSyntauri, while adding many modern features such as full velocity control, a much more extensive modulation routing system, tempo synced LFOs, a pair of delays, and two monophonic modes. The noise and oscillators are able to work in the original alphaSyntauri "low-resolution" modes, or can be run in modern high-resolutions. Phosphor can accurately model the original sounds of the alphaSyntauri, yet still provide new paths for sonic exploration.


• Two complete oscillator/envelope sections modeled on the original topology of the alphaSyntauri.

• Each set of partials can run in "lo-fi" mode, emulating the gritty digital voicing of original, or in a modern mode for alias-free sines.

• The noise can be either "lo-fi" digital shift-register noise per the original, or modern white noise.

• Two complete delay sections with LP/HP filtering and cross-feedback.

• Two tempo-syncable LFOs with multiple modulation destinations.

• A large complement of presets included that show off the extensive sound generating capabilities of Phosphor, including some famous alphaSyntauri presets directly ported from the original.

• TUN file loading for alternate tuning and scales.

• MPE (MIDI Polyphonic Expression) capability for MPE controllers like the Roli Seaboard, Linnstrument, and Sensel Morph.

What’s New

Version 3.0.9

NEW IN 3.0.9:

1. When you have the modulation assign window open for a slider, and touch the on-screen keyboard, you can now play without closing the mod assign window.

2. MPE mode now works correctly in hosts that support it.

3. Minor bug fixes and optimizations.

Ratings and Reviews

4.5 out of 5
14 Ratings

14 Ratings

mrdogheadSHoGoAT ,


Just enough depth to allow endless versatility, but it withholds everything that might give the impression of excess or overelaboration. The new version retains its connection to the original hardware in its general architecture, but, even more than 2 did, the app far exceeds anything possible with ‘80s hardware.

The additions in Phosphor 3 all improve the instrument without damaging the immediacy of the old version. There remains some room to grow, but this is a joy to use and it no longer cries out for additional features (as much as I enjoyed 2, it wanted some of this extra stuff).

I’ll skip the blow-by-blow of what’s best about the synth. Let’s just say it’s very much worth buying, even if you have little idea of what additive synthesis is about. If you know a little, so much the better.

Thanks to the devs - and a special thanks for making the on-screen keyboard worthwhile. Too many devs forget this platform is based on mobile devices - and that for most of us, usually, that mobility doesn’t include a lap full of MIDI devices.

Now if the music devs could impress upon Apple that allowing moving or temporary deactivation of the up-swipe dock would be an enormous improvement for the music-app-buying segment of the user base. I have tried. Apple does not listen to users. Maybe successful devs would have better luck?

;$&-%#! ,

I keep coming back to it

Sound design is a bit hit and miss for me with this synth, but it has a ton of great presets and has become my go-to poly synth when I want a nice chord sound or pad.

JohnFBP ,

Weird little synth

Very versatile noise maker. Just scratching the surface of this but I can tell it’s deep. Worth the $

App Privacy

The developer, Audio Damage, Inc., has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer’s privacy policy.

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