I have a MAC G4 that I've used for audio. There are several issues. If you have a high end system and you compress your music, you will notice and it will not sound good. If you take your signal from the computer's headphone jack, it will not sound good. Worse, when you increase volume, you'll hear a hum that is coming from the computer. However, if you use the computer as TRANSPORT and take the signal out of the computer through the USB or Firewire port, bypassing the computer's internal DAC, and play it through a high quality outboard DAC, you can get sound that will compete with CD players costing thousands of dollars AND you will get the convenience of having hundreds of CD's available at the click of a mouse. At first, I tried USB soundcards that cost a few hundred dollars, but it only offered a slight increase in quality over the headphone jack. But, when I invested $1,000 in an Apogee USB Mini-Dac, it was a home run. Amazing sound. Natural, musical, detailed, deep, wide soundstage -- everything. Will it compete with the BEST digital players? That will be a matter of opinion, but in my opinion, players like Wadia offer impressive sound and may give you a tiny bit more detail, but to my ears, the sound is a little digital for my taste. I don't want this to turn into a flame war and I am not trying to diss anyone's gear. But, to my ears, the hard drive plus Apogee sounds more natural and involving. I admire it a little less, but enjoy it more -- if you know what I mean.
Finally, to my ears, based on my taste, my Emm Labs gear is the best digital gear. My computer plus Apogee isn't in that league -- and the Emm Labs also offers SACD playback -- but, what the Apogee has in common with Emm Labs is a natural sound. The Apogee USB Mini-DAC costs $1,000 and the Emm Labs DAC costs $10,000, so I don't want to oversell the Apogee Mini-Dac -- it isn't in the same league with the Emm Labs. But, after listening to Emm Labs, I have become spoiled and find it hard to listen to other gear. But, I enjoy the Apogee Mini-Dac. If you have the budget for Emm Labs gear, IMO, nothing is going to touch it. That's my opinion, based on my taste. But, if you are looking for a system that can compete with players costing 3,000 to 5,000 while offering convenience, put this on your list of things to consider.
The Cosecant tubed USB DAC is also intriguing. Given my eye and ear opening experience with the Hard Drive plus Apogee, I am prepared to believe that it is possible to get amazing sound from a computer Hard Drive given the proper outbord DAC.
I have not heard the Cosecant, so I cannot offer any opinion on its sound versus Apogee.
