Phosphor 2 review – does Audio Damage’s first iOS synth hit the sweet spot?

Download from iTunes App StoreAudio Damage appear to be on a mission when it comes to iOS music apps at present. I’ve reviewed Rough Rider 2, Grind Distortion, Eos 2, Dubstation 2, QuatroMod, Pumphouse and Replicant 2 all within the last couple of months.

However, as I reported a few weeks ago, Audio Damage have also added a synth app to their catalogue; Phosphor 2. The effects apps have been universally well received….  so is Phosphor 2 keep up the high standard? And where does it sit within the very crowded iOS synth marketplace?

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Whereas all the other apps listed above have been audio processors/effects of one type or another, Phosphor 2 is Audio Damage’s first iOS synth offering.  Again, it is a port of a desktop version that has, in one form or another, been around for a number of years. The iOS version apparently brings exactly the same features as the desktop version both in terms of controls and sound.

Audio Damage do iOS synths…. Phosphor 2.

The synth is modelled upon aplhaSyntauri, which is a vintage (early 80s!) digital synth originally designed to compete against the Synclavier and Fairlight but at a fraction of the price (US$1500 as opposed to US$40,000!). The system involved a physical keyboard combined with a software-based engine that ran on a AppleII computer….   and it apparently sounded pretty aggressive in an early digital sort of a way.

Anyway, despite being innovative and finding favour in terms of its sonics, it was not a lasting commercial success. And, as those hankering after the sound can now get very close indeed for just US$59 for Phosphor on the desktop, you would have to be particularly geeky (and loaded) to seek out on of the few remaining working hardware examples….

The app ships with a good collection of presets, some based upon the original alphaSynturi sounds.

… and, of course, you can now get the essence of that sound in an iOS app for even less money…. The app runs as a stand-alone processor and offers IAA support but I suspect most folks will probably be most impressed that it is also supplied as an AUv3 so you can run it within a suitable host such as Cubasis, AUM, Audiobus, etc. as required…  and, yes, you could run multiple instances if you wished.

Used via AU – as shown here within AUM – the control set is split across two pages.

Glowing engine

The interface looks very slick and, when used stand-alone, aside from a few under the hood setting (for example, the MIDI options), the bulk of the controls are housed within a single screen. Programmers will, I think, find they very quickly get the hang of things but even a synth novice ought to find their way around without too much trouble. As an AU plugin, the controls are split across two pages….  but this is nicely done and easy to navigate.

You can configure an external mod wheel to control the LFOs (and therefore the modulation options within the synth).

The top-strip of options provide the usual access to global settings, the preset system, some ‘generate a random patch’ options, a switch to go between poly, mono and retrig playback modes and the master output level. Beneath that, on the left/centre you get the main oscillator controls (with the delay effect controls beneath these), while the right 1/3 of the display is dominated by the modulation options.

The synth engine is built around a twin additive oscillator/envelope model. While the oscillators offer the (limited by modern standards) same options as the original hardware, there are a few places where Audio Damage have respectfully enhanced the specification and these give the user considerably more options in terms of the sonics.

I had no problems getting the app to respond to external MIDI.

There is rather a nice PDF manual for Phosphor on the Audio Damage website (written for the desktop version but a good read for iOS users also) that does a good job of introducing the reader to additive synthesis. In essence, oscillators generate sound by stacking multiple sine waveforms, each with increasing frequency, to form a basic tone. Each waveform is referred to as a ‘partial’.

In the original hardware, you could stack up to 16 such waveforms. However, in Phosphor 2, you also get options for 32 and 64 (see the screenshots) and this does, of course, give you a much wider range of tonal options. In both oscillator displays, the left-most slider represents the volume of the fundamental (lowest-frequency) waveform….  and you simply use your finger to draw in the levels required for each of the sine waves (partials) to want use use (with those to the right adding more high-frequency content).

The oscillators and amplitude envelopes allow for each touch control when tweaking your sounds.

In both oscillator windows, you get menu options to clear the display, switch between 16, 32 and 64 partials, to load a few oscillator presets and, via the rather cute ‘space invader’ graphic, to switch on a ‘vintage’ mode that adds a lo-fi element to the oscillator output. Immediately beneath to partial display is the amplitude envelope window for each oscillator. This are pretty simple to use….  but don’t just drag the nodes as you can also change the nature of the slope between some of the nodes for different volume envelopes.

Below the amplitude envelopes are various sliders to tweak the sound of the oscillators further, adjust their velocity response, level, the pitch offset between them, add white noise and control pan. These are all fairly obvious in use. Perhaps more interesting is are the two cross-modulation sliders. These allow the two oscillators to modulate each others frequency so that their sounds interact rather than just blend. Frequency modulation (FM) is something associated with Yamaha synths but, apparently, Phosphor 2’s cross-modulation is inspired by the Synclavier….  Either way, once you have got your head around the basics of Phosphor’s engine, this is where to look to spice things up a bit…. although it is easier to explore if you start in 16 partial mode as lots of high-frequency content, when cross modulated, can just end up as static-like noise (although that’s cool also in the right context!).

In stand-alone mode, all the controls within a single screen make for a great programming experience.

Delayed reaction

Between the oscillator section and the compact virtual piano keyboard is Phosphor 2’s only ‘effect’. However, it is a rather nice one, offering independent control over left and right channels of a delay. Tempo sync is offered and each channel includes easy to use filtering, feedback and cross-feedback. Of course, as Audio Damage also offer a good range of effects apps in an AU format, you can always add a few extras via your AU host if you need to.

More modulation

As well as the frequency modulation offered between the two oscillators, Phosphor 2 also includes twin LFOs for more traditional sound modulation options of the synth’s key parameters. The LFOs offer a choice of waveform types and can be tempo sync’ed. You can also modify the shape of the chosen LFO waveform using the Shape knobs.

The two LFO’s can then be set to target pitch, pan, the amplitude and noise elements of both oscillators, as well as the delay effect’s filters, via the various sliders provided. The sliders are set to zero (no modulation) in their central position with more extreme +ve/-ve modulation when moved to the left/right. This is all very easy to get your head around…  yet offers enough options to keep things interesting.

The modulation options are easy to use but very effective.

The control set is rounded off by the Delay Mix slider and Portamento (the nature of the pitch glide when the synth is in mono or retrig modes) sliders located bottom-right.

Does Phosphor burn bright?

In use, I didn’t experience any technical issues with Phosphor 2 on my large format iPad Pro and using iOS10.3.3. The synth was also happy to respond to my external MIDI keyboard, and seemed very solid used stand-alone, in Audiobus 3, AUM and Cubasis. The MIDI routing options in Audiobus 3 also seem to be supported. I have seen a couple of users reporting problems with the app in a couple of forums (although I suspect you can always find a few folks having issues with almost any app if you spend enough time digging in forums)….  but my own experience was entirely without incident.

Phosphor 2 worked fine as an AU plugin and supports MIDI routing within Audiobus 3.

So what about the sound? In principle, additive synthesis ought to let you create almost any sort of sound if you can combine the various stacked sine waves in the right fashion. With up to 64 of these and two oscillators, Phosphor 2 ought to be quite a flexible sound source. It is….  and the presets do a decent job of demonstrating this variety (although I’d have liked a few more presets and, in particular, a few more bass-based examples)….  There are some very nice sounds amongst the keys, lead and pad categories…. and the vintage vibe of the alphaSyntauri does come through in a lot of the sounds. If classic synth rock is your thing, then I think you will like Phosphor 2 a lot. If contemporary EDM is more your music of choice, then there are perhaps more obvious synth choices (for example, Poison-202, if you want an AU-based synth).

That said, you can roll your own sounds with a more ‘modern’ feel once you have familiarised yourself with the synth engine and those cross modulation options also make it possible to get into almost sound design territory with ease. Indeed, this ability for almost anyone – PhD is synth programming or not – to get into sound creation with Phosphor 2 is, I think, one of the app’s real strengths. Whether stand-alone (a single screen) or via AU (two screens), the compact control set and easy to use oscillator sections are a pleasure to use and explore.

One of the appeals of Phosphor 2 is that it is very approachable even for the less experienced of synth programmer.

If the prospects of programming heavyweight synths such as PPG Infinite bring you out in a cold sweat, then Phosphor 2 might be just the antidote. We are fortunate to have a number of ‘getting started with synth programming’ synth apps available to us on the App Store; Phosphor 2 is another excellent option in that class. Oh, and it is pocket-money priced and has AU support to boot….

In summary

There is a lot to like about Phosphor 2. It sounds great (albeit perhaps within a palette of sounds that reflect its heritage), is a doddle to use and seems to perform well. And while it is currently iPad-only app (an iPhone version is apparently on the way), like all Audio Damage’s iOS offerings to date, it is modestly priced….  this time around just UK£5.99/US$5.99.

I think it would make a great addition to any growing iOS synth collection but it is perhaps most obviously going to appeal to those looking to go ‘all AU’. Equally, it is another fine example of a synth that a less experienced synth programmer could have a lot of fun with. Indeed, I think the app hits a ‘sweet spot’ in a number of ways; sound, format (AU), easy of programming and price. What’s not to like? Check out the iOS preview trailer and the desktop demo videos below….  and then hit the App Store download button to find out more.

Phosphor 2

Download from iTunes App Store

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    1. Liking this one very much. Had only played with it for five minutes and had saved two user presets. Very mix friendly sounds, I’m betting. I find a lot of the very lush sounding synths wow initially but then are hard to place.

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