I'm lucky enough to have enough non-identical modules to create quite
a few voices. So you could say I'm running polyphonically but I would
characterize what I'm doing as multitimbral and monophonic. I'm
certainly not playing changing chords like on my polysynths. (I'm not
counting the use of several VCOs in an otherwise mono voice as a chord).

On the surface it seems like you could just get a bunch of Dark
Energy modules or something similar and a multichannel MIDI to CV
interface with polyphonic assignment of voices and think you have a
polyphonic modular... well to me at least one big aspect is totally
missing in the polyphonic puzzle... how in the world do you change
the sound in unison other than slowly manually going up to each voice
and changing one parameter at a time. What I at least feel is
essential in a poly modular is the ability to control all the voices
from a common set of controls..

With a fixed architecture voice there has been an answer since the
1970s. If you build a voice where every parameter is voltage
controlled you can use a set of common controls on them or even a
microprocessor could store every parameter for later recall. The
stumbling block in a poly modular is the patchability.

Florian mentions the SEM. They were built by adding extra hardware
into the Oberheim Two, Four and Eight etc. voice polysynths. It's
worth noting that they were not intended as modular synths. But an
interesting aspect is the individual voices can be easily "patched
out" modular style, as Tom Oberheim is offering this year as a
configuration. One thing I and I'm sure others were thinking when he
announced them was if he or a third party will make a a poly voice
assigner (maybe the midi units are chainable I'm not sure) and then
what existed in the 70s but hasn't been reissued is the programmer
which attempts to send parameter values to each voice module.
Unfortunately it didn't deal with every parameter let alone the patch
cords.

The Korg PS series took a very unique approach. It does not allocate
voices like nearly all polysynths including the Obergheim polys do.
You get a separate VCF and VCA for each key but there is a set of 12
(24 or 36 for the 3200 and 3300) shared tunable oscillators with
octave dividers and which is more an organ approach than a VCO style
approach. The 3200 had memory recall of knob position. The patch
field that qualifies it as a semi modular is not polyphonic.

I believe polyfusion back in the 70s has a polyphonic CV keyboard but
correct me if I'm wrong, nothing else supporting polyphony so it was
change every parameter and patchord manually.

Emu had a poly keyboard and a programmer that could store a few
values so I guess that was a start but incomplete. I see Cyndustries
has a simple module with some small groups of CV values

In the early 80s you started to see polysynths with matrix
modulation, which was steps toward a modular but not actually a
modular. These synths added a lot more modulation options but the
underlying architecture was still fixed and the matrix exists more or
less within a CPU.

Considering the limitations and hybrid technology in the Korg PS I
don't really think the approach is that similar to the Nord Modular.
The Nord Modular is virtual. As long as there is computing power
available you just add an instance of the whole thing. Nothing is
physical.

It was funny to see the reproduction of smaller scale Korg Legacy
MS-20 complete with patch cables, The hardware MS-20 was monophonic,
The software simulation however is poly, similar to the Nord. The
novelty twist with the Korg is the controller is a physical patch
interface. No sound or voltage goes through the mini MS-20 but it
senses the patch cords. and adjusts the virtual patch to include them

I think the Buchla 200e changed things because the modules use
encoders and most of the pots can have their settings stored and
recalled. A few pots are just physical and are not stored as well as
no oone has yet made a third party module that has knob recall. While
there have been at least one matrix style storable patchbay out there
that could be used in theory for some patch cord storage, I believe
Buchla is the first to build one as part of a modular system. It's
not perfect if you use many patch cords since it's a small matrix.
You could buy a few of them though there would still be some
compromise. It has up to 4 buses running for voices to more easily
achieve polyphony direct from MIDI if you have enough of the same
modules (or different modules if you don't mind).

nick