I wanted to share this site with you: http://www.sg-acoustics.ch/analogue_audio/index.html
Unlike rod elliot's site it is not very widely known on the internet.
If you don't know which Opamp you should take for your next audio design check this out: http://www.sg-acoustics.ch/analogue_audio/ic_opamps/pdf/opamp_distortion.pdf
It is pretty actual (2009) and has a good variety of opamps from differen suplliers.
There are also some schematics for audio products (preamps, PSU etc).
Take a look at it, you won't regret it!