Yeah, I'm afraid Florian's right.

To broaden the discussion a bit, modular synthesisers aren't particularly well suited for FM synthesis and polyphony. FM synthesis is usually implemented digitally because making another oscillator consists of writing a few more lines of code and getting a slightly faster chip, rather than spending another £200 or so on a tangible oscillator (not to mention the cost of the envelope generator, VCA, etc).

But before you get put off analogue modulars, there's a whole bunch of things you can do with them that you can't do so well in the digital domain. All the tiny imperfections add up to sound more quirky and interesting. You can touch physical knobs and leads to make changes, giving your eyes a rest from the screen and your hand a rest from the mouse. The inability to save a patch means you can't ever quite recreate anything you made before, but you will instead discover new sounds each time, and hone your patching skills faster. You will be forced to make the sounds of each track sound at least slightly different from the last, something everyone should be doing anyway. Negative points have a strange way of becoming plus points in this respect. And when you start throwing things like spring reverbs into the mix, and all those filters, you really get a completely different world of sound to what you can get from a DX-7 or software. Gritty, unstable, untamed beasts of sound that you're struggling to keep under your control, that sound powerful, strange and alien.

Now, if you want to make Krautrock, you probably only need a fairly basic A-100 system and maybe some Mellotron or Orchestron samples, and you'll be set for at least half a dozen albums or so. :)

I'd recommend reading Gordon Reid's Synth Secrets: http://www.soundonsound.com/sos/allsynthsecrets.htm (The list's in reverse order.) It's a great guide to patching sounds together, and will give you plenty of ideas about which modules you'll suddenly "need". :)

Anyway, I'd recommend making clean, clinical music in software, and gritty, organic music using something like the A-100. While both can do both, it's much easier to play up to each instrument's strengths.

All the best,
Zoë.