Op Amps

[Josh Rowe]

Hello All!

I've been following the discussion about op amps over the last few 
days, and I have a few questions about all of it.

1) I hear a lot of talk about noise levels of different op amps.  I 
presume when most of you talk about noise levels, you are referring 
to equivalent input noise voltage.  Here are some of the eq noise 
voltages -- LF351, LF411, TL081 : 25 nV/sqrt(Hz) typ;
  OP07 :  350 nV/sqrt(Hz); OP176 (update to 5534 according to AD) :
 6 nV/sqrt(Hz).

With these voltage levels, won't the thermal noise from a resistor be 
much greater (in the uV) than any of the op amp noise levels?  I got 
the equation for resistor thermal noise from a book by Malvino
 (sorry I don't have the title at this paticular moment--I can post
 it tomorrow if anyone wants it).

2) What is the full info on the article by Jung (is that correct?) 
about op amps for audio applications?

If I've made a mistake somewhere, feel free to point it out.

Josh Rowe
jrowe at everest.acpl.lib.in.us