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NE570 or SA571

Started by electrocutioner, May 19, 2010, 12:24:34 PM

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electrocutioner

I have built the PT80 delay and I'm really satisfied with this unit. Nice repeats and an easy project (if you have a ready made PCB  :icon_wink: ).
I was wondering if there is any difference if someone will use different companders. I have bought and use the SA571. Will I have any difference if I use NE570 or another compander?

PRR

The letters are just the maker. The '0 used to have "better specs" than the '1, but not so you'd notice. I suspect that after the initial batch, they were all the same.
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Mark Hammer

The prefix is more about the buying and selling of different organizations.  I gather what was once Signetics (the NE prefix) is now Philips (the SA prefix).  The 570 is pin-for-pin compatible and supposed to be marginally better, spec-wise, than the 571.  The impact that simply using companding provides, however, vastly outweighs the small differences in performance between the two.  However, if you have both lying around, or if the 570 is available for pennies more, the 570 (whetherNE or SA) is prefered.

PRR

> marginally better, spec-wise

It comes back.

A telephone company would have thousands of these things, perhaps several in cascade, interconnected "randomly" (luck of the dial), in a system with tight gain tolerance and nobody at the volume control. A telco would pay for sub-dB tolerances.

Our systems are far simpler.

NE, SE, LM, uA, etc are just manufacturer or distributor prefix. May or may not mean they were made in different plants. The 570/571 would have been tooled in at least two factories because a major telco project can't be frustrated if a sole-source factory goes on strike or burns down; IBM demanded that Intel allow NEC to tool-up for the 8o88 CPU so that IBM would not be at Intel's mercy, military contracts usually require a second-source, etc. However the heyday of 570/571 was decades back and we are living on leftovers.

OnSemi still seems to have tooling; a 2006 datasheet with SMD and Lead-free part numbers. The SO (SMD) package seems to be readily available, the DIP package is on close-out at places like Rochester who buy-up obsolete parts for long-range profit.
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electrocutioner

Thanks!

I bought the cheapest I found. Just, wondering why the other one was more expensive....
So the difference in prices may be at the availability of each.

BTW, the prices of these ICs are a little bit expensive at "guitaramp/stompboxes parts" suppliers!