> GD2, I believe the VCF and VCA is contained on the CEM chip being
> used for the VCO, thus the lower price, and probably the reason
> to include all such things in one module. Perhaps somebody could
> confirm this...
>
> Tony

To disclose the "secret": the core of the A-111-2 is the CEM3394. This
circuit contains a triangle based VCO, a 24 dB VCF with VC resonance, an
audio VCA and several pre-patched auxiliary VCAs (e.g. for linear FM of
VCO -> VCF or 2 opposite as crossfader working VCAs at the VCF audio input).
The CEM3394 was e.g. used in the Sequential Circuits Sixtrack and some
Simmons drum modules. This explains why the A-111-2 has a filter and VCA
available "for free".

Best wishes
Dieter Doepfer