App Description

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!

iPad Screenshots

(click to enlarge)

Phosphor 2 screenshot 1 Phosphor 2 screenshot 2 Phosphor 2 screenshot 3

App Changes

  • August 01, 2017 Initial release
  • June 13, 2019 Price increase: $5.99 -> $6.99
  • June 14, 2019 Price increase: $5.99 -> $6.99
  • June 14, 2019 Price increase: $5.99 -> $6.99
  • June 14, 2019 Price increase: $5.99 -> $6.99
  • June 15, 2019 Price increase: $5.99 -> $6.99
  • June 15, 2019 Price increase: $5.99 -> $6.99
  • June 16, 2019 Price increase: $5.99 -> $6.99
  • December 03, 2019 Price decrease: $6.99 -> $4.99
  • December 10, 2019 Price increase: $4.99 -> $6.99