Hey,Why don't you build the amp with OPA2132? It is very easy to use because I know it can withstand anything (other than electro-statics ... you know sweaters in dry-weather thing.)
DC offset stuff is very difficult to understand unless you play with the actual thing. I myself didn't believe it till I saw it on a multimeter. (But the calculation is fairly easy. 
Input offset current multiplied by bias impedance (sorta) )
This problem is rather insignificant if you are willing to bias the opamp with low resistance. I think it would cause you much problem unless you have TUBE CD player or TUBE preamp. (or a very, very special solid state preamp) In fact, 1k ohm seems to work good enough with my MP3 players, computers, and CDP. ... I have seen many CMOY-like amp with NJM4556 and NJM4580 in this manner. (Being Japanese, I see these more often.)
However, I vividly recall when I was a noob, I felt deathly uncomfortable with non-zero offset. So that is why I think you ought to go with OPA2132. On top of it, I am obsessive-compulsive so I think I spent a good part of a month once.
Being a Gentoo user yourself, I think you are also obsessive-compulsive. (Or I would usually call people like you "crazy". Debian seems more reasonable for me. ... Lately I wimped out more and went Ubuntu. Super-Noobified.) Heh.
Tomo
posted 03-02-2008 06:46 AM CST (US) 
