IR3109 ?

[Haible_Juergen#Tel2743]

> Sometimes Roland might select a component from another manufacturer (such
> as Curtis) but in some cases Roland designed their own. When Roland, or
> another company, designs their own chips (such as Roland's IR3109 filter),
> products can have a unique sound, hopefully resulting in a unique value.

Mike, surely each chip has its own character and own value. Differences
between various CEM and SSM products, or discrete solutions a la
Moog and ARP are quite well understood now, but there seems to be a
lack of knowledge about the internals of Roland chips. The
general behaviour, building blocks etc are known of course.
But what are the specialities in technology?
How would a IR3109 gm cell differ from a CEM3320's or SSM2040's ?
If you have any information about this, be sure it would be highly
welcome! (I'm crossposting to DIY - would be better than on AH).

Thanks,

JH.