I am using an Apple Mac Mini to play Apple Lossless files ripped from CDs directly to a Denon AVR-3311CI amp through the HDMI cable. There is a sort of "mushiness" to the music that is not present if I play the original CD on a DVD player connected through the coaxial S/PDIF input to the Denon. I played the same CD on a Blu Ray player that connected to the Denon via HDMI and I believe it sounded very slightly mushier than through the standard DVD player.
I am not much of an audiophile and didn't set up this stereo system with high quality in mind. But now I'm terrified that I'm starting down the road that leads to buying $1,000 speaker cables. :-)
Anyway, my best guess at the moment as to what is causing this mushiness that I am hearing is that there is too much jitter in the signal from the Mac Mini to the Denon. Does this sound like a reasonable conclusion? Is HDMI particularly susceptible to adding jitter? Do you think it would be worth looking into a USB to S/PDIF converter and a DAC? Is there another possible cause that I should examine?