need a ne570 for delay builds, are the cool audio v751D replacements ok?

[njkmonty]

need some ne570  for delay builds, are the cool audio v751D replacements ok?

about to build a dm2, deluxe memory man and a EHX Echo Flanger

they all require the chip however  last time i got some from eBay  half were dodgy

is a commander chip like an op amp, " just throw it in?  or is there a big differences  like with BBD chips?

[greaser_au]

Coolaudio reckon their V571 is a functional replacement of the NE/SA571.  I was surprised to see that their data sheet is dated 2008!

IIRC the NE571/SA571 is a slightly lower performance pin-compatible version of the NE570, and a cursory comparison of the 'electrical characteristics' tables of the two Philips data sheets indicates the only 'serious' difference between them is that the 570 is good for a Vcc of 24V,  and the 571 is limited to 18V.

The fact that the application note (Philips AN174) seems to use the two devices interchangeably suggests that as long as your Vcc will not exceed 18V it should be a drop-in replacement in most applications.   Not a very useful response, but I'd suggest that it would be worth a shot to try a 571 if you can get your hands on one. 

david
greetings from sunny Adelaide    

[Kipper4]

http://electricdruid.net/noise-reduction-with-companders/

[Scruffie]

Short answer, yes they're good I've put one in a vintage memory man before and it sounded exactly as it had before.

One thing I have noticed on a few occasions and I don't know if it's to do with manufacturer variation or user error is that sometimes the SA571 don't bias up the same as the NE/V chips.

[Kipper4]

Just out of intrest what biasing changes did you have to make Scruffie?

[Scruffie]

It wasn't on my builds, I don't think i've ever used the SA brand my self, it was helping other people debug theirs. I can't remember the exact details but it happened for a few people and the outputs were misbiased either up or down so signal wasn't passing, could mean the internal resistor values are different but I have no hard evidence to back it up and the problem could have been on their end, just an observation I thought might be worth mentioning.

[duck_arse]

the 571 shows a higher distortion figure than the 570. there is also the 572 which seems equivalent, and 22V supply limited.

[greaser_au]

The 572 allows separate attack and decay for the gain cell control, but the trade-off is that it has no internal opamp. For the applications in question, a separate opamp  will be required for each half,  but given the performance of the 570/1 opamp (it's a 741-grade) this probably isn't a big problem.

david