iPad Screenshots


Full manual available at the Audio Damage website.

Phosphor is an unique instrument modeled on the alphaSyntauri, a vintage digital additive synth from the early 80s. The original alphaSyntauri required an Apple //e to operate, but we've gone ahead and eliminated the middle-man, and now you can have this classic digital synth in your iOS device, no 5.25" floppy drive necessary!

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.

• XML preset system, with copy-to-clipboard, for sharing presets in forums and with your friends.

• AudioUnits V3 version for use in all AUv3 hosts, like AudioBus 3, AUM, BeatMaker 3, Cubasis 2, GarageBand, etc.

• Standalone version (with full single-panel UI) with Inter-App Audio and BlueTooth MIDI capability.

• iPhone version coming soon!

Ratings and Reviews

4.3 out of 5
19 Ratings

19 Ratings

doug funnie ,

Underrated gem

Love the sound of the oscillators. So warm and fuzzy. Simple to program, great for pads especially, and definitely beats having yet another subtractive-synth.

The Space Invaders buttons being hard to touch is my only complaint.

And to the guy who couldn't find any info on Phosphor from the Audio Damage website...maybe you should check your internet connection. It's all there.

Lundberg02 ,

No sound, no manual, no email address

I opened the app and tapped the keyboard, no sound. I looked for the manual at the Audio Damage web site, the site doesn’t list Phosphor 2 as a product.
. I am updating my review to 3 stars because I was eventually able to contact the developer and resolve two problems, sound and manual. The default volume is about 75%. I keep my iPad Pro volume at about three of the little blocks unless it’s music. That combination resulted in no sound.
The developer sent me a long url for the manual which turned out to be pretty good, although it describes the plugin, not the iOS standalone. It does not talk about managing the presets and this will be a problem. There is no obvious way to restore to default and the presets just sit there begging to be fiddled with. Once you change one, you can’t get it back. There is no explanation for installing user defined presets. I can see this app has potential but the manual needs work.

Film less Soundtracks ,

Vintage Fun and a steal of a deal!

When you begin writing your own presets before you even play any of the Factory presets, enough said! This will go up in price I have no doubt. Get it while it's cheap. Five stars, easily! Thank you to the manufacturer.


Audio Damage, Inc.
8.7 MB

Requires iOS 9.3 or later. Compatible with iPad.

Age Rating


  • Family Sharing

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

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