Companders

Why are you looking at such an old part ?

Graham

There is a project of an old effect, the Rocktave Divider for guitar that I would like to implement Bye

Eeyore ha scritto:

Yipes, looking at the schematic gives me the willies. For many reasons. It's a strange mix of analog and digital and unobtanium IC's. Worse yet, the circuit has probably been fine-tuned to use some of the less defined areas of the IC's operating points. It's hard to get the right attack and decay and lock-in characteristics without considerable part-juggling.

It should probably go through a complete circuit refreshening, with modern components.

Unforunately there are lots of these 70s style designs knocking about on the web using obsolete components.

Graham

Eeyore wrote in news: snipped-for-privacy@REMOVETHIS.hotmail.com:

Often, it's exactly that rough and dodgy design that makes the sound that is sought after. Not that I'd have thought a divider was anything much beyond a flip-flop thinger with a square(ish) wave output that tracked the input frequency.

Exactly... so if we suggested using some more modern companders, using gilbert multiplier cells, RMS extractors,... it might sound too "clean", or have abrupt lock-in transients.

So the poor OP probably needs to search the web -- somebody probably has a few of these chips.

son of a gun, eBay strikes again. Look there for NE570-- you can buy them in lots of 3, 4, or 50, at very reasonable prices.

web

And of course, many people coming along simply want to build something, and don't have the background to realize it is using old components.

It's been a number of years, but there was a time when people would routinely ask somewhere in the sci.electronics.* hierarchy about where to get tunnel diodes, and often it was clear that they had no real specific use for one (as in repairing something, or some esoteric use where another device hasn't come along to do the same thing), but simply wanted to build that "wireless mic" or whatever, and were unaware of how brief a time tunnel diodes had any impact on the electronic scene.

Michael

Isn't it more like they want the specific sound of a classic effect, so they want to copy it part by part. Any quirkiness of the original design is important, because someone isn't setting out to make an "octave divider" but get that sound "like so and so used on whatever".

Michael

eBay is truly remarkable in this respect ! i've used it a few times for electronic components myself.

Graham

But the original poster never asked where to get them, he simply wanted to know the difference between the NE570 and the NE571.

From memory, it was relatively small difference, but I can't think of what book I'd have the information in.

I've found them in early cellphones, the brick portables and the car units, made at a time when there was little or no surface mount devices and the ICs were mostly recognizeable part numbers. When the phones started getting smaller, obviously they had to do better integration in the ICs.

Michael

It looks like the datasheets are available still, so that might help the OP.

Graham

snipped-for-privacy@FreeNet.Carleton.CA (Michael Black) wrote in news:edkhtf$9dp$ snipped-for-privacy@theodyn.ncf.ca:

Of course, that was the point of my first sentence. I considered that they might just get one to borrow long enough to send an impulse through it and capture it with Sonic Foundry's 'Acoustic Mirror', but I doubt an octaver is something you can capture that way. Hence my second sentence.

There's a couple of tunnel diodes in my Tek465 - and you're not having them!!!

They are the same chip, the NE570 is just a higher spec selection, with max supply voltage 24V vs. 18V for the NE571.

Thankyou David ;)

David DiGiacomo ha scritto: