jitter reduction?

One of the principle benefits of using a computer transport is that virtually all of the jitter associated with a traditional transport is eliminated. The other main problem area is associated with the SPDIF implementation.

Yes, you can buy various reclockers but IMO (and the experience of virtually everyone else on these forums) it is unnecessary.

What will greatly affect the quality of your playback is how you rip (import) your CDs. Use Apple Lossless with Error Correction on (under Preferences/Advanced/Importing) and all other sound features (Preferences/Playback) off.

I ran a Toslink from my G5 to my TriVista for a long time with excellent results.

Here is a paper on the subject:
Eric Benjamin and Benjamin Gannon, "Theoretical and Audible Effects of Jitter on Digital Audio Quality", 105th AES Convention, San Francisco, September 1998. This paper concluded that the threshold of audibility of jitter on normal music signals is around 20nS.

Since the average cheap CD player is around 1 ns then in theory one should be fairly safe even with a portable player for next to nothing. In practice this is not good enough for most audiophiles however, and jitter has become a hotly contested subject. Many people claim to hear jitter and can tell you what it sounds like.

While I have not yet incorporated my Mac into my audio system, I can state that I have heard great improvement with the Camelot Dragon Pro II when it comes to jitter reduction. Some of the notable names, Genesis Lens and Monarchy, work but the Camelot gear was clearly better.

I discovered that with higher quality transports with their supirior powe supplies and build quality—I use a Wadia now—I did not feel the need for additional jitter reduction, though on even some top notch transports, the Camelot Dragon Pro II did add some focus.

I find that the most noticible effect of jitter reduction is improved bass. Inner detail gets better. You begin to hear individual voices and instruments more clearly.

I am interested to incorporate my computer into my system, but after consultations with other audiophiles, I expect that like the rest of any good system, the quality of the sound will depend on the quality of the DAC, cables, power supply and other components. I know you can't cut corners.