35 - the next step

[jhaible]

>So it is exponential? How did it track the keyboard then? Or didn't it?
>Where was the keyboard signal applied? Via one of the mod inputs? But in
that case the pot would affect the >tracking.
>Did the MS-20 keyboard output an 1 V/oct signal or some V/Hz signal? Maybe
it had a 1 V/oct signal for the >filter and such, and a V/Hz signal for the
VCOs?

I only was the owner of an original MS-20 for a short time, so someone
correct me if I'm wrong.
But I don't think one could have the filter tracking to the internal
keyboard. The keyboard
had Korg's patented resistor divider that put out a V/Hz CV.  If you plug
this voltage into
one of the VCF's modulation inputs (there is no dedicated keyboard tracking
switch),
you get a slightly strange response. If you control both, the VCOs and the
VCF from an external
V/Oct source, you should get them tracking. But I haven't tried.

Is this a design flaw ? Probably. But considering the most interesting
interaction of the filter's
own resonance frequency and an external signal, this mistracking even has
its benefits.

JH.