OK, here's my attempt at an answer...Len a question for you. I am not a technical boffin so do not see the difference between a DSP synth like the Noah, Yamaha AN board etc and a VSTi. The Arturia, and no doubt other VSTis, do not work off samples, they are modelling just as the Noah is. What is the difference please? Is it not down to whether you prefer the sound or not? I personanly like my Akai SG01v better than many of the sounds in my Roland SRX Classic Keys card.
The difference is all in the math that is used to calculate the soundwaves. Noah and Creamware cards use dedicated chips to do the calculations, whereas VSTis use the computer's CPU to do the calculations. While a Pentium CPU may be very powerful, and able to do many different TYPES of calculations well (e.i. jack of all trades), the chips used by Creamware (called SHARCs) are more suited to do calculations relating to sound production, and possibly other media calculations, like video processing. You must have heard some VSTis that don't sound very clear or lively, compared to other VSTis. The difference is that the better sounding VSTis have better calculations (likely taking more processing power as well). Better calculations meaning (1) simply better math equations, (2) higher internal bit rate, and (3) higher internal sample rate. 2 and 3 are important in the same way when you do math calculations you're supposed to hang on to all the extra digits until the very last step, and only round off at the end. The final result can't help but be more accurate, and in this case, it's all the details in the waves that are produced that make the sound more realistic. I have yet to hear analog modelling that sounds anywhere near what the Creamware products generally provide, but that's a matter of opinion (I think a lot of people agree with me though). A big part of what makes real analog so thick is the natural variation in voltages that occur in the circuitry, and 'faking imperfections' is not as easy as you would think, it actually requires a lot of attention to detail. Take all the filters and envelopes off a synth and listen to one of its oscillators. Does it have bite, does it have grit, is it rich in overtones, or does it sound like a whine? You can't make a synth sound richer than its basic components, and if those are compromised, all you can do is try to hide it as best you can, maybe no one will notice (see : Korg MS2000). Some of what the accelerated SHARC chip calculations provide is very quick reaction to playing, not just *when* you hit the note, but *how hard* you hit the note, how *quickly* you start one note after another. Try a hammer-on trill on different mono synths and you'll see a difference in how they respond.
Some of what I like about the Noah is how it responds to playing - something as simple as a PWM pad is FUN to play (using the Pro-One) - little differences in key velocity cause the sound to vary in a very natural-feeling way. You can't help but play an instrument BETTER when its interface reacts to your playing nicely. Think of a high quality guitar with strings a half inch off the neck - no matter how nice the tone is, it's hard to play expressively because just getting a note to sound is too difficult.
