Hi Monroe

> Could you tell me in what properties and roughly to what magnitude are the
> Cwejman VCA's better than Doepfer's (i.e. attenuation, noise, response
> speed, etc.)

I don't have papers here and I do not intend to do research on this.
Neither attenuation, noise, nor response are the big problem - but
distortion around the through-zero region (which is basically the old
A-class versus B-class problem).

You also have to take into account, that nearly every synth we know
about uses for the VCA the same type of integrated circuit with the same
problems. Whether these are CA3080, BA6610, LM13600, LM13700 or the
Curtis CEMs or (lowcost-)SSMs does not really matter (where the CA3080
is the worst under the aspect of distortion). Only a very very few
modular systems of the first generations, and a few today modular
systems use better VCAs. But the huge(!) mass of vintage and modern
synthesizers (Moog, Oberheim, ARP, Roland, you name them all) uses the
CA3080.

Doepfer used Curtis 3381/3381 in the first series of the A130/A131 and
today CA3080.

Florian