NE572 as VCA?

[Paul Perry]

At 12:51 PM 13/09/99 +0200, Juergen.Haible wrote:

>And, most important: Is it possible to link two halves of a 572 for stereo
>compression ? I think it *should* be possible to hard wire the capacitor
>pins together, i.e. pin 4 to pin 12, and pin 2 to pin 14, and only one set
>of 2 capacitors. I've never tried it, 

Neither have I, but it isn't obvious this would work.
I'd sum the 2 channels, feed the two rectifier inputs.
But, in the pathological case where the 2 channels are out of phase,
thyere is naturally a problem.
The data sheet makes unjustified assumptions about my intelligence..

paul perry melbourne australia

BTW, made a great automatic level control from one! but, it really needs a 
gate.. thinking of using the voltage on the attack cap to switch a 
comparator & then a fet grounding ckt, unless someone has a more elegant idea.