AW: NE570 book from Midwest Analog Products

[Haible Juergen]

	>> Bought it & read it.....
	>> I liked it, always had trouble understanding the Signetics data
	>> sheets and application notes on this and the NE572....
	>> Also, astonishingly enough, shows how to replace internal op amp
by an
	>> external one with better specs.
	>> A movie would have to be pretty good to be more worth seeing than
this!
	>> paul perry melbourne australia
	>> 
	>> Something not addressed is whether you can use steering diodes to
give
	>> unequal attack/decay times. Anyone?
	>
	>It is likely that you could do that to form an ADSR module.
	>
	>Regarding the history of the NE570 and NE572 in audio applications;
Tom
	>Henry mentioned to me that in the 70's, Craig Anderton was the
first
	>person to really dive into these chips and deeply understand the
	>workings. He then began publishing electronic music circuits using
the
	>chips. In the last year, Tom has fallen into some of these chips
and
	>relearned the Anderton depth of knowledge. The book is the result
of his
	>studies.

The Paia Vocoder (wasn't this designed by Craig Anderton, too ?)
uses the 570 for envelope followers and VCAs. So each channel consists
of nothing more than the filters and half of a 570 chip. This is truely
brilliant design. It *is* quite limited, because of the symmetrical A / R
times of the 570, but keeping in mind that it's a very low cost product,
it is very, very elegant.

I've never seen other 570 applications that are equally brilliant - is there
anything similar in the book from Midwest Analog Products ?

(The external opamp stuff you mentioned is directly from the data
sheet, as well as some fast attack / slow release limiters using external
diodes and comparators, btw.)

JH.