Thank you very much for this response. I didn't even know these things exist. Apparently there are also converters that can be put between the computer and the DAC. Now I need to find out which DAC ... will check out the Bel Canto and others. Sites I have seen seem to say that the stand alone DACs will produce better sound than the sound cards (ATI, Nivia) installed with some computers - maybe because the computer is a "noisy environment" or maybe because the sound cards are intended more for sound effects than for music. Apple makes an airport device that apparently can act as a DAC, but I have no idea how good it is. My sense so far (after several attempts to find anyone at Apple who is knowledgeable) is that Apple doesn't care much about this stuff. Seems kind of short-sighted.
what is a lazy old audiophile to do?
I am an old audiophile. Left behind by technology. I'm tired of replacing tubes, want convenience, if not simplicity (maybe simplicity). I decided to put my CD's on a computer hard drive and play from there. I have a new Pioneer SC-07 ( I know, not audiophile), new Imac with all the latest, Kef 205/2 speakers. The only connection from the Imac to the receiver is the headphones out from the Imac - (tiny). I have no idea why Apple is so uninterested in audio. I may send back the Imac and get a Dell with sound card and HDMI out, which I can connect to the Pioneer. My question: is this stupid? That is, am I trying to do something that will never satisfy my ear? I care a lot about the sound (have a thirty year old pair of Snell Type A's in the other room that I love). Can I get decent sound with the convenience of the computer? How? I don't really care about surround sound or movie crashes; I just want really good audio through my computer.