I just picked this app up for my office iMac.
https://itunes.apple.com/gb/app/bitperfect/id455545700?mt=12After annoying issues with audio dropouts and distortions from the Mavericks OS and firewire/usb devices (Orpheus in my case), I was resigned that good audio was not happening with this machine. Everything seemed to be getting sample rate converted and who knows what else, it sounded terrible to me.
I started looking into audio players that were bit perfect or allowed the use of integer mode and came up with "Bit Perfect" from the app store. It works with iTunes as a player and "hogs" the audio device. Having just installed it, iTunes is now playing tracks that were recorded at various sample rates, and the Orpheus is locking up to each new SR. It seems to sound significantly better than iTunes without it. I still need to do some null testing to see if it is indeed bit perfect, though.
I can now use this machine to audition tracks that clients upload, so this is a big help.