[sdiy] VCA distortion - bad

[Ian Fritz]

At 09:58 PM 6/14/2003, harrybissell wrote:
>This is with the topology where the negative rail of the OTA is varied with
>the CV. I saw this in a Craig Anderton design (and also in Electronotes as you
>mentioned)... but I have never tried it.
>
>It certainly saves having to use a PNP current source to drive the Iabc pin
>(referenced to the negative rail) but I always wondered if it would affect the
>headroom.
>
>So anyone tried this and vouch for it ???

Harry --

It's an old trick originally from W. Jung.  I have used it, for example here:

http://home.earthlink.net/~ijfritz/sy_cir5.htm

   Ian