[sdiy] NE571N compander from "The Electronic Goldmine"

[Robert Kent]

On Tue, 8 Jun 2004 synth at oldmail.charlielamm.com wrote:
> I just got their summer flyer today, and they are
> advertising NE571N Compander IC, 16 PIN DIP, for 99c (USD) each.
> Not on their web site as far as I can tell....

http://sales.goldmine-elec.com/prodinfo.asp?prodid=9511

> I have read about the NE570 on Thomas Henry's site, which I understand has
> better specs.  But is the 571 useful?  Or is it too noisy, too high in
> distortion or otherwise not good for what we do, even at this price, which
> I assume is good?

I am unclear on the difference between the NE570 and NE571 after reading
datasheets which covered both chips. I believe they are functionally very
similar. I substituted an NE571 in Thomas Henry's Clangora drum synth
design with no modification and it seems to work well.

> I take it these chips aren't that easy to find?

Philips produced these as part number SA571. For a period of time the
NE/SA571 were ubiquitous in their original intended application as a
cheap telco compandor; many portable cellphones which are old enough
to use a lot of discrete components contain one. I'm not aware of any
current production.

The chips were never regarded for their heroic audio quality. For
serious studio applications like broadcast compressors the companders
made by THAT Corp. are more appropriate.

> Anyone have a link to the NE571 datasheet link they can provide? BTW,
> Thomas Henry has a link to the 570/571 app notes: I know of that one....
> http://www.semiconductors.com/acrobat/applicationnotes/AN174.pdf

Also check out the Compander Cookbook app note:

http://www.semiconductors.com/acrobat/applicationnotes/AN176.pdf

I'm surprised to find that Philips no longer has these datasheets
online, but here's what I dug up:

http://www.ampslab.com/PDF/ne570.pdf
http://www.fulcrum.ru/Read/CDROMs/PHILIPS/datasheets/D14/SA571.pdf
http://62.236.156.23/ideaport/d/SA571.pdf (same as above)

Electronic Goldmine also sells the SA571 in SOIC form for $.49:

http://sales.goldmine-elec.com/prodinfo.asp?prodid=5532

Midwest Analog sells the NE570 for $5.00. Small Bear Electronics
offers the SA571 for $4.50. This is the first source for the DIP
version I've seen at such a low price. Thanks for the tip!

--Robert Kent
  hanuman at ccsi.com