AW: 13600 (was VCA chips)

[Haible Juergen]

Interesting results, and quite surprising. Well, maybe not that
surprising, as this Serge article is the one and only reference
on this I'm aware of. Might as well be that I have a blurred 
memory about this article - someone should dig it up, just
to be sure.

The version which I have built can be found at
http://www.synthfool.com/diy/hjmp2.gif
but honestly I don't remember the exact measurements results.
Note the the 1k normalisation at the input. As the input is DC
coupled, and the OTA input pins are not exactly at 0V, a varying
driving impedance will unbalance the VCA. Not the most
elegant circuit for sure, but it works for the purpose it was
intended.

Just a few questions about the measurements: Did you have
the same gain / the same load resistor in both cases ? Is the
diode impedance low, compared with 1k ?

JH.