NE572 as VCA?

[The Dark force of dance]

Y-ellow Paul.

At 07:09 PM 09/12/99 +1000, Paul Perry wrote:
>I know you can use a NE570/NE571 as a VCA..
>but, I'm having a bit of trouble doing it with a NE572.
>Anyone done this? Any hints?
>(I scored a batch of surface mount NE572s..)

	I know this is not of much help but. I've done this. It was so long ago I
can't remember how but it was a bitch. They're not too bad when you get 'em
running but they're a bitch to get them there. Component values are
relatively critical and the design notes misleading.

I'll see what I can find in the way of my old CN2R notes. Might turn up
something. All I can remember for now is that I had to squeeze the whole
thing down with trim pots before I could make sense of the damn things.
It's all got something to do with internal bias as I recall. Or I might be
thinking of the older versions. I'm a bit confused this early. It's first
thing in the afternoon. 

Once you do get them running, the quality is pretty damn good. Certainly a
quantum leap over the old 571s. Which are probably best left to function as
noise generators.

Hope this helps.

Be absolutely Icebox.

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