I tracked down these two soft-synths because they're both fairly unique — not only different from each other, but also very different from others currently on the market. I'd venture a guess that 90% of the virtual instruments on the market fall into one of two categories: emulations of analog synths, or emulations of classic instruments. For instance, Arturia has made a business of selling (very excellent) soft-synths that are component-level models of classic subtractive analog synths (similar to how a lot of plug-in developers have modeled classic EQs and compressors, like the Neve 1073 and UREI 1176). Then you have your software synths that emulate instruments, like Hammond organs, Wurlitzer pianos, and Mellotrons, and these usually use some kind of sample-based topology or physical modeling algorithm. It's a bit ironic that today's laptop or iPad has far more computing power than any of the complex mainframe computers of the early digital music era, but we use that power to mostly emulate classic analog synthesizers and electromechanical instruments! 

Now, I love my Arturia CS80 [Tape Op #57] and UAD Fairchild compressor [#63, #76] models, but what happened to the promise of early digital music? Thinking back to the late '70s and early '80s before MIDI even existed, the source for digital music news was Computer Music Journal (MIT Press). I had a subscription and read every page, even though I could barely understand most of it, and all the math formulas were way over my head. The possibilities, however, were super exciting! Besides sampling, which obviously achieved mainstream adoption, the two most common synthesis methods discussed back then were FM, which begat the Yamaha DX7, and additive, which mostly only saw the light of day in universities and some high-end digital synths like the Synclavier. As the '80s came to a close, physical modeling became popular with the publication of the Karplus-Strong plucked-string algorithm, along with wave-guide modeling, but none of this really hit the mainstream. Kurzweil briefly made the K150 Fourier Synthesizer, a monster additive synth but would only work with an Apple IIe, a computer that's pretty hard to find these days, so now the K150 is basically a boat anchor, and it sells on eBay for $250. We're also seeing some iPad apps that use physical modeling, including the Karplus-Strong algorithm in particular. But now that affordable computers and mobile devices can finally handle the complex math you need for these kinds of digital synths, we're mostly focused on recreating another variation of the Oberheim Two Voice or Moog Modular. That's really a shame, as digital synthesis can produce some really unique and beautiful sounds that analog synthesis can't, and even sounds that sampling falls short of capturing.

Let's look first at Morphine, a very cool and very advanced additive synthesizer from Image-Line. Additive synthesis is conceptually very simple, which is why it was one of the first synthesis schemes. The Hammond organ could be considered the first additive "synthesizer" in analog form, albeit one with very little envelope or dynamics control. Digital additive synthesis existed in universities as an offline process in the '60s, but in the '70s, microprocessors became powerful enough to do real-time additive synthesis. Commercially, the Synclavier (1977) was able to do additive synthesis, as was the more affordable Apple IIe–based alphaSyntauri (1980). Additive synthesis uses simple sine waves to recreate the harmonic structure of complex waveforms. For instance, the fundamental frequency of any sound (also its pitch) will have multiple harmonics, so for instance, a piano note played at A440 will have a fundamental at 440 Hz, a second harmonic at 880 Hz, a third at 1320 Hz, and so on. The tricky part is that each harmonic has a different amplitude envelope. Think of the 3D graphics from early Fairlight CMI displays (or in the Fairlight iPad app), or the cover (and iconic t-shirt) of Joy Division's Unknown Pleasures, and you should be able to visualize what I'm talking about here. Morphine's additive synth engine is able to generate four simultaneous additive synth voices with up to 128 harmonics per voice — and then "morph" between them. Hence the name. While you can't put a separate envelope on every single harmonic, Morphine can interpolate between a series of spectral "snapshots" to create some pretty complex sounds, while offering an immense amount of user control. If you want to, you can have a different spectral snapshot on every note of the keyboard!

One of the goals of early digital synthesis was to analyze sounds using Fourier analysis to break them down into their harmonic components, so they could be re-synthesized using additive synthesis. Of course, the earliest samplers rendered this all commercially pointless, and the race for the most realistic grand-piano sample was on! How boring is that? It's unfortunate that we lost sight of the potential of additive synthesis somewhere in the late '80s or early '90s, but it's nice to see the folks at Image-Line picking it back up. Morphine adds a lot of nice features that you'd expect in a modern soft-synth, like built-in effects and an ADSR-style amplitude envelope. But the really huge feature that Morphine includes is a re-synthesis option that allows you to analyze and re-synthesize sounds from imported samples, which is some pretty amazing sonic programming tech! This app pretty much blows away a Synclavier and is a big step up from the only other additive synth app I'm aware of, which is Audio Damage's Phosphor, an emulation of the alphaSyntauri synths. Phosphor is inherently very retro and limited.

Finally, Morphine sounds awesome! I was not only impressed with the additive emulations of classic instruments, like piano, but even more impressed with the sounds that aren't based on anything real. If you want to break out of the sonic palette of drums, bass, guitar, and subtractive analog synths, Morphine is a great tool for the job.

So overall, I'm gonna give this synth a big thumbs up, but I do have a few small gripes. My main one is, why didn't they add an envelope-controlled LP/BP/HP resonant filter? Even vanilla samplers like SampleTank have this option, and it would allow for classic subtractive synthesis techniques, post-additive processing. There's a noise generator in Morphine that does have a resonant filter, so the code is already there, and hopefully, we'll see this made available in a future revision. In the meantime, you can use a filter plug-in post-Morphine — which brings me to my second main gripe. Morphine only works as an Audio Unit plug-in. I know Pro Tools kinda sucks for using virtual instruments, but it's still a very popular DAW amongst professional studios and users, so here's hoping for an AAX version further down the road. As it stands, I'm only able to use Morphine with my built-in speaker/headphone jack as it doesn't seem to work with my Universal Apollo interface [Tape Op #95, #99, #101, #111]. It should be noted that Image-Line also publishes FL Studio, which was originally known as Fruity Loops and was the DAW that a lot of the "laptop music" crowd adopted over the more popular DAWs of the time; so here's hoping Image-Line sees the point in taking Morphine to a bigger audience. But that said, Morphine sounds amazing, so minor quibbles aside, I'd highly recommend it to any sonically curious readers out there. I also want to point out that Image-Line's Harmor synth is an even more powerful additive synth with subtractive synth features, like a resonant filter. Unfortunately, Harmor only runs on Windows, so I was not able to try it.

So on to Chromaphone, which is a very different type of synthesizer, and in some ways, a bit more specific in its topology. Whereas Morphine feels really advanced in a hacker/coding kind of way and harkens back to the early days of digital synthesis, Chromaphone has cracked the code, so to speak, and it's a very easy-to-use and intuitive instrument, even if it is a bit less sonically versatile than Morphine. Chromaphone uses physical-modeling algorithms, which means that a mathematical formula is used to describe and model the action of a physical component, be it a plucked string, stretched membrane, or tuned resonator. The math behind this is very complex, but Applied Acoustics Systems has done an amazing job of completely hiding the complexity to create an extremely flexible and powerful instrument that's both fun and easy to use — and that's quite a feat!

Some physical-modeling algorithms have a particular "sound" to them, and you hear it when you know it, so they're not always as realistic as additive synthesis can be. But physical models are usually much more realistic sounding across multiple octaves, avoiding weird high-frequency aliasing or low-frequency Cookie Monster artifacts. And when physical modeling hits the nail on the head, so to speak, it sounds better to my ears than any sample-based or other algorithmic process I've heard. The marimba models in Chromaphone, for instance, are pretty much perfect. With physical modeling, you can get some very, very realistic simulations of real instruments, but more interestingly, you can create very, very "realistic" sounding instruments that have never existed! Think of all the wacky instruments Blue Man Group builds, and then envision being able to build them on your laptop, and you begin to see the power and possibilities of Chromaphone.

The basis of Chromaphone is in its different modeling modules: Mallet, Noise, and Resonator. Resonator is then further subdivided into several different algorithms — String, Beam, Plate, Marimba, Drumhead, Membrane, Open Tube, and Closed Tube, as well as Manual, which allows for a custom resonator from a four-partial additive synthesis model. The other very cool thing in Chromaphone's topology is that you can use two separate Resonators in parallel, or in an even more advanced coupling mode. When coupling two Resonators, you can more closely simulate real instruments like an acoustic guitar, which is a string coupled to an open tube with a funny shape. This is some serious DSP voodoo, but in Chromaphone, it's deceptively easy!

Hats off to AAS for not only making Chromaphone the first user-programmable physical modeling instrument that I'm aware of, but also for making it super fun and easy to use. The GUI on this is so intuitive that anybody who understands the basics of music and sound should be able to create patches within minutes without cracking the manual. I should also mention that AAS has been breaking ground on physical modeling for quite a while now (although many of the company's previous instruments were more focused on emulations, so they didn't really grab my attention).

Both Morphine and Chromaphone are sonically amazing and way more fun to program and play than most virtual instruments on the market because they're so different and new — even if the basic technology here is decades old. Both of these instruments are very different from each other but have a couple of things in common: They both are able to accurately simulate complex, real instrument sounds without sampling. But what's more interesting is that they can both create complex "real"-sounding instruments that don't yet exist and perhaps will never exist in the physical world. This last concept especially seems so much more interesting than modeling the Minimoog or some other classic analog synth. Free, fully functioning demos are available for both instruments.


Morphine $159 direct


Chromaphone $199 direct



Tape Op is a bi-monthly magazine devoted to the art of record making.

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