An Introduction To Kurzweil’s VAST Synth Engine

Kurzweil’s V.A.S.T. (Variable Architecture Synthesis Technology) synth engine is more than 30 years old. But – between the fact that it was way ahead of its time and the fact that it’s been significantly enhanced over the years – it is still an extremely deep and rewarding platform for synthesis.

This video, via Lars UK, offers an introduction to the V.A.S.T. synthesis technology used in the Kurzweil K series of synths, including the K2000, K2500, K2600 and even their recently introduced K2700.

If you’ve used one of Kurzweil’s V.A.S.T. synths, leave a comment and share your thoughts on the video. And if you know of other good resources for learning the V.A.S.T. platform, share them in the comments!

15 thoughts on “An Introduction To Kurzweil’s VAST Synth Engine

  1. … it’s the K2000 not K200?! It has the original V.A.S.T. that is very viable in this day & age, also the 0rig SMP-K hardware-that makes it evermore still a powerful piece of kit even these days (& now with ZuluSCSI it’s damn near like having flash-memory or a non-volatile hrdw sampler) IMHO it’s sonic’s are a bit warmer than it’s K-series siblings & BTW this new K2700 has no user sampling in the traditional sense which tooo me makes it more akin to the PC series keyboards, not that that’s a bad thing just think they should’ve called it (a) PC5 thanx folks.

  2. That’s an excellent tutorial. It’ll either win you over or scare you off. V.A.S.T. is one of the best synthesizer environments ever devised. Its very modular, but also beautifully organized. One of Soundtower’s editors can be a big help. They cover the Ks, but also the PCs and Fortes, for example. https://soundtower.com/

  3. Perhaps the closest thing in software is Kontakt. I’m very biased, but editing keymaps, dsp, and modulation is much easier and more pleasant with the K2xxx series. Kontakt’s GUI is tiny.

    There are weaknesses (aliasing, slow mod scan rates, puny RAM ((by today’s standards))) and dated facotory content. But the flexibility is off the charts. There’s a learning curve, so not for everyone, but there’s also a helpful community.

  4. If I need the instruction on VAST, I wouldn’t purchase this tutorial series. I’m sure that the author spent a great deal of time mucking around with his K2500 and adjusting values of the VAST parameters. However, after watching only the first 3-6 min of this example, I know that it won’t be much of a help for most people who are trying to grasp what VAST is and how it works. If you are interested in learning vast, the best way remains to buy a beat up K2000, that still makes sound, download Darwin Grosse’s Tutorials from the web (a few months ago Synthhead ran a tribute piece here about Darwin, after his death, and I’m pretty sure the links were provided in that thread), and just go through the tutorials. Even though the K2000’s implementation of VAST isn’t covered there, once you get through what is there, understanding how to add on to your knowledge and explore things like FUNs becomes very easy. The essence of VAST hasn’t changed much since the K2000. Over the years and through the models things have been added and subtracted, but with the knowledge you get from the rudiments of K2000 VAST, you can, pretty much, muck with just about any Kurzweil that allows you to edit the vast parameters pretty easily. Thirty years ago I started playing around with VAST on a K2000, since then I’ve had at least one of every model in the K-series. My current studio master controller is a K2700, and for the eight years prior to that, a PC3K8. When the K2700 arrived, once I figured out how to enter the editor, I was off playing around with the VAST parameters and doing stuff to samples that only VAST can do. I know I’m biased but it REALLY “is the sound”.

    1. What advantages does the K2700 have over the earlier models you’ve owned?

      I’ve got a tricked out 2500, and it looks like the 2700 adds some things, but also has less connectivity. The main thing I dislike about the 2500 is aliasing in the oscillators at the high end.

      1. Sorry it took me so long to find the question. The one big advantage of the K2700 is that it is currently new. Each of the K2xxx line synths has some advantages, as well as disadvantages. Up until the K2661, the K2000’s biggest advantage (here in the 21st century) is its 61-key format and its weight. Currently, the biggest advantages of the K2500/K2500R are that it will do everything a K2000 will do (and will do it exactly like a K2000), it brought the sampling capacity from 64MB to 128MB (where it remained through the PC3Kx series), and it is the last K-series synth to use the Digitech effects processor. It is for that third advantage that I keep two K2500RSs available for projects when that quaint “retro” sound of the Digitech makes the K2500 sound so, well, “Kurzweil”. Up until about two years ago when I finally found a K2600RS to install in my main studio, my only experience with the K26xx series was a K2661 that I purchased new around 2007. In my opinion, the K2661 is the actual pinnacle of the Kurzweil K-series, from a practical standpoint. If you use any ADAT-Lightpipe, its 8-channel Toslink connectors are a Godsend (and as far as I know, it was the only Kurzweil synth to offer this capability). Also, the K2661 was the first K-series synth, since the K2000, to offer a 61-key keyboard. Inside that case (almost the exact same size physical package as the K2000) sits a fully built out K2600 with most of the available options. VAST had matured quite a bit with the 2600 line and things became much more flexible. The audio engine was, by then, almost glitch free, and the sampling option was still available. After I purchased the K2600RS, I remembered just how wonderful the K2661 actually was, so I purchased and refurbished one that sits in the only 61-key physical position available in my studio. Also, because they are getting rarer, I purchased a second one in “good condition” about six months ago that I’m current refurbishing and that I intend to keep as a backup. I also keep in storage a K2000S and a K2vx, both fully expanded in terms of sample memory and P-RAM with LED-backed displays, that I am going to sell as soon as the Kurzweil K2xxx market corrects (and I’m pretty sure it will when enough “younger” people become aware of what these things are and what they are capable of, given the preponderance silly digital synths that are the fad today).

        I purchased the PC3K8 for two reasons. I needed a hammer-weighted action keyboard with a “lighter action” that still felt good to me (my arthritis was demanding that), and because it was a “K” compatible Kurzweil instrument. Over the three decades that I’ve had Kurzweil synths and samplers in my studio, I’ve managed to collect a sample library of just over 80GB (that may not sound like much in today’s TB memory terms, but these aren’t just samples, these are Kurzweil K2xxx samples and programs. Many come from a time when 16MB was a massive amount of sampling memory, and even 16MB was plenty to develop sample/VAST combinations that allowed incredible flexibility and produce sounds so wonderful they are more than useful today). Anyway, I must admit that I never got too deeply into VAST programming on the PC3, by the time I got it I was pretty much satiated and I’ve always had Kurzweil synths where the VAST engines were more accessible and more meaningful for the synth. I’m of the belief that with the PCx lines, Kurzweil stopped being a “synthesizer” and became a “run-of-the-mill” ROMpler “workstation”. Right now, I can’t think of a track that I have saved for posterity that has any sounds on it that were created with the PC3K8 sound engine.

        When the K2700 was revealed a couple years ago, I knew I would have to get one as soon as they were available. Kurzweil hyped them correctly for me so that the purchase was inevitable. Once a few people had their hands on them, the question as to whether or not the “K2xxx” name was befitting for them became click-bait fodder. In my opinion, the answer to that is both “yes” and “no”. My first reaction to it was “This should have been called the “PC5”. On the surface, it appears as an updated PC3K, with a new FM sound engine thrown in, finally more sample RAM, and an audio interface. It still looked like a newer ROMpler with features that made it competitive with other flagship “workstations”. Then as I started getting more into editing programs in it, it took on a whole new essence. As I said, I never played too much with PC3 VAST. Well, having the FM architecture available, I re-investigated the world of VAST programming. I’m really amazed at how far VAST has come since its K2600 iteration. Sometimes I feel like a kid again when I find a new use for an old FUN friend in this new environment. So, as a true synthesizer, this thing says Kurzweil all the way down to its recursively demanding VAST heart. Maybe I would have had a similar experience with the PC3, but I never had the expectations of a K2xxx Kurzweil when I bought it, so I never even explored its potential.

        The massive amount of sampling memory available on the K2700 is more impressive than it sounds, considering that anything I have imported into it from my library has required, at most, only minor VAST tweaks to get going. Also, it’s large enough to accommodate longer samples from the days when I had a Korg Kronos 2 in the studio (i.e., the keyboard that occupied that 61-key position until I got the K2661). While I think it is silly to compare the K2700 with the Kronos (or any like workstation), because the sheer power of the Kurzweil sound engines for crafting “synthetic” atmospheres makes it much more than a workstation, in retrospect, I can see how the K2700 can possibly fill the void for somebody who needs great piano and orchestral sounds, but also wants to experiment with the nature of musical synthesis at the same time, using some of the most powewrful tools currently available.

    2. Good stuff. I recently bought a K2500 that needed some work. It is surprising how VAST has stood the test of time. Thanks.

  5. U must be just playing the factory presets & the contemporary ,orchestral ROM blocks have plenty of sounds that don’t alias. V.A.S.T. has anti-aliasing tools that are like nothing else but u have to dig deep tooo find the way to utilize them especially when you use the drum layers in conjunction with each other for things other than percussion sounds so to speak and it doesn’t cut into the polyphony bcos of it’s voice allocation system that other makers have yet to match thanx folks

    1. Since the “Midiboard”, every “Pro” Kurzweil synth with a keyboard (except the PC4) has used a keybed manufactured by Fatar (both hammer- and synth-weighted). So, in reality, Kurzweil hasn’t made a keybed in over three decades. Also, the K2700 took forever to get from initial advertising to the marketplace. If I had to guess, Fatar was nowhere close to final development of a keybed with polyphonic aftertouch when the design of the K2700 was finalized. Also, I’m still not sold on the concept of polyphonic aftertouch in a hammer-weighted keybed, anyway. The Hydrasynth was my first practical application of polytouch (followed by the Iridium). It surprised me how different a playing technique is required to get the most from it. I found it hard enough to learn with a synth-weight keybed, so somehow I think that learning curve would be compounded dealing with a hammer-weighted action. The K2700 does respond to PT MIDI messages, though, and playing it with the Hydra or Iridium through MIDI is great. Also, I’ve found that the CME 37-key board fits nicely on top of the K2700 in front ot the main keybed, giving it a “2nd manual” of sorts.

      1. “Fatar was nowhere close to final development of a keybed with polyphonic aftertouch…”

        Has that changed now with the Iridium, which apparently has a Fatar keybed with polyphonic aftertouch? Also what do you think of it?

        I am used to aftertouch on weighted as well as synth action keybeds – I just want it to be polyphonic!

        “The K2700 does respond to PT MIDI messages, though, and playing it with the Hydra or Iridium through MIDI is great. Also, I’ve found that the CME 37-key board fits nicely on top of the K2700 in front ot the main keybed, giving it a “2nd manual” of sorts.”

        That is exciting! Personally I really like that the Sequential/Dave Smith instruments respond to polyphonic aftertouch MIDI input (now if only they’d bring back the Prophet T8 keybed…) I also like the Xkey though its limited key travel can be a pain.

        1. Yes, the Iridium does have a keybed with polyphonic aftertouch. I’m not sure what you mean by ‘Has that changed”, but my guess is that now that they have developed the technology, they will probably sell it to anybody that wants to incorporate it in a synth. I love the Iridium keyboard. It is much better feeling than the Hydrasynth’s. If I had to describe it, I’d say it feels close to a TP-8S, but with polyphonic aftertouch. It really is that good.

          Monophonic aftertouch is fine for a hammer weighted keybed, however, I don’t think it would be very easy to make the most out of a polyphonic aftertouch hammer-action keybed. I realize that the Midiboard was both hammer-action and polytouch, but I think that that was an historic curiosity than anything else. Playing a keyboard with polyphonic aftertouch takes a much different kind of dexterity than does playing a normal keyboard or one with monophonic aftertouch. Tow your fingers travel in order to take advantage of the aftertouch is much defferent than how they travbel if you are just playing notes. Also, differences in finger weakness become much more apparent. When you add the hammer action to that, you have more than doubled the learning curve.

          I like the Xkey, for what it does and its build size. It is a great introduction to polyphonic aftertouch in a very easy to play format. It’s nowhere near the Iridium (or the Hydrasynth, for that matter), but it does get the job done.

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