[AdamM]

Here's a link i'd like to share called 'The Listening Sessions'

These guys did a massive onslaught of microphone and preamp comparisons, on numerous sources.

Many many tests and combinations.. like  hundreds  of them, with downloadable audio files

Judging quality over an mp3 is questionable in it's own regard!  But you can tell differences between them more than individual quality in itself.

Worth checking out if you're thinking about a new mic or preamp.  They just might have done a battery of tests with it.

http://www.thelisteningsessions.com/sessions.htm

Cheers,
/A