570/571- vs 572 Was RE: [sdiy] Automatic gain correction for Overdrive

[jhaible]

> The 571 is a good noise source. It was designed for telephone systems and
> probably isn't good to use outside of that. I've built several Noise
> reduction units around both chips and whilst the 571 works in this
context,
> it can often defeat the purpose with it's own noise. The op-amp is lousy.
> Really truly awful. The 572 gets round this problem by not having one. You
> need to use an external Op-amp of your choice.

If you are using the 571, you can also ignore the internal opamp and use a
better
one. Still not the same as a 572, but SNR is much improoved.

JH.