Because not listening to it at all gives you more pleasure than listening to it with the best equipment you've got?
I think you should consider the possibility that you may be an audio geek after all.
Still no CD player: you let iTunes rip the CD using Apple Lossless.
Besides, you assume mp3's are 128 Kbits. When you get to 320 Kbit mp3s, most hi fi geeks can't make out the difference in blind tests. (they can always if the test isn't blind and they know which source is which – just like wine taste experiments).
Tests in which I knew what is what were completely worthless. I nearly always thought that I could tell the difference and that ability magically disappeared in blind tests.
I can tell the difference between 128 KBit/s MP3 and a CD, though.
Some resources on the topic: http://www.turnmeup.org/ Some examples: http://www.youtube.com/watch?v=3Gmex_4hreQ http://mastering-media.blogspot.com/2008/09/metallica-death-...
My advice: Spend $50-100 on a good pair of headphones, and you'll find more justice there than in hi-fi setups costing thousands of dollars.
I'm no audio geek, but I can easily tell the difference between CD and mp3 for some of the music I listen to. I even have a CD of Beethoven's Ninth which I've never actually listened to because the audio equipment I have can't do it justice.