The power of the original Synclavier II and Synclavier instruments lay in the combination of Fourier styled synthesis and FM built into the user functionality of the units. The combination of technologies 'under the hood' created stunningly organic sounds for the time - even in sounds that weren't necessarily simulations of 'real' instruments.
Frequency Modulation on the Synclavier worked differently than I’ve seen it implemented on just about every other synthesizer I've come across. Unless you’ve actually worked with one, it’s hard to grasp just how uniquely FM was used within the context of a Synclavier environment, especially if your only experience with FM is, say, on a Virtual Analog that maybe has one rotary knob labeled 'FM'.
I’m sometimes asked today if there’s a way to get that Synclavier sound on any of the contemporary VA’s.
Yes and no:
I can coax steady state Synclavier-like sounds (pads, bells, hits) out of any virtual analog. The thing with the Synclavier though, is that the FM aspect of it was used to integrate expression into the sound, not just as a superficial modulator, as it is on so many other synths.
For instance, one would use the FM to create the sliding bow to enhance the realism of the underlying tonal string sound; or the breath on a horn's mouth piece for a brass patch. This was a big concept in its day, that by layering a primary tonal sound with secondary audio information whose color mimicked the noise of a musician working his or her instrument could capture and really enhance the realism of any given simulated sound.
But even more exciting, this meant one could create a totally unique patch, that sounded like nothing else in the universe, and program information into it that made it feel like a 'real' instrument, albeit one you've never heard before. And that was a sonic revolution.
You can't do that on a virtual analog synth. But, –yes– you can approximate some of those otherworldly Synclavier leads and pads if you wanted to.
And for what it's worth -and I mentioned this somewhere online before- the Waldorf products do an exceptional job making pads that sound like vintage Synclavier patches.