[sdiy] Companders

Craig Critchley craigc at nwlink.com
Tue Aug 27 07:17:57 CEST 2002

That Corp. has the THAT4301 analog processor, which contains an RMS
detector, an exponential VCA and three opamps (one is dedicated as a
current-to-voltage converter for the VCA).  The primary purpose for it is
audio compressors. Its several building blocks on a chip, rather than a
purpose-dedicated device, so it might be more flexible.

Unfortunately That only sells multiples of 20 (one tube), and they aren't
distributed through any of the normal online distributors that I'm aware of.
They are also more expensive, in that quantity, that the SA571 price you
found, but it is designed for audio rather than telecoms, so it may have
better specs.

Another possibility is Analog Devices's SSM2165 and SSM2166, which are
microphone preamps that include compressor circuits.  I think those can only
be used as compressors, though, and I don't think they're cheaper.


----- Original Message -----
From: "Scott Stites" <scottnoanh at peoplepc.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Monday, August 26, 2002 2:49 PM
Subject: [sdiy] Companders

> Hi All,
> I was doing some casual checking on compander chips.  I
> noticed that Small Bear Electronics has the DIP version
> of the SA571 for $4.50.
> Electronic Goldmine has the surface mount version of
> the SA571 for $0.49.
> I was wondering if there are other current production
> compander IC's out there?  Are there any schemos of
> companders built from discrete components that anyone
> might have to share?
> Thanks,
> Scott
> ________________________________________________
> PeoplePC:  It's for people. And it's just smart.
> http://www.peoplepc.com

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