On 6/3/07, Larry T. put forth:
doesn't look like anything more than a rectifier wrapped around an
amp, and still requires an external filter cap. While there are much
more sophisticated envelope followers out there, either on a chip
(eg. several THAT products) or using discrete components (Harry
Bissell has published a couple of them), this doesn't look like one
of them. If you are not going to use the rest of the SA571, then it
seems like a waste of money. An SA571 costs around $5, a TL072 and
four 1N4148 diodes costs less than $1. YMMV.
>As for the NE571 (Philips SA571 too it appears), do you have a circuitFrom the look of it, the envelope follower section of the SA571
>in mind? The price does not seem unreasonable for 2 followers if it
>uses as few external parts as I suspect. But I'm not much at design.
> OTOH, I can do breadboards and PC board assembly pretty well.
>(Jameco has NE571's, and a lot of companies have SA571's.)
doesn't look like anything more than a rectifier wrapped around an
amp, and still requires an external filter cap. While there are much
more sophisticated envelope followers out there, either on a chip
(eg. several THAT products) or using discrete components (Harry
Bissell has published a couple of them), this doesn't look like one
of them. If you are not going to use the rest of the SA571, then it
seems like a waste of money. An SA571 costs around $5, a TL072 and
four 1N4148 diodes costs less than $1. YMMV.