Since upgrading to 10, all my music sounds flat and tinny. I have an audio cable running from my Mac Pro into my stereo. If I play a song via iTunes, it sounds

Since upgrading to 10, all my music sounds flat and tinny. I have an audio cable running from my Mac Pro into my stereo. If I play a song via iTunes, it sounds like crap. If I plug the cable into my iPhone and play the same song, it sounds fine. Anyone else experiencing this?