Preferred Audio Output, USB or 3.5mm?


What is the preferred 2CH audio out selection from an iMac (or PC) to my preamp, USB or the 3.5mm headphone jack? Either output will run through a separate DAC before the preamp. Mainly listening to iTunes or Pandora.
stevensctt
The latest MacBook Pro Models (2010) provide an audio signal via the "mini display port". An adapter may be purchased that converts this mini port to a female HDMI. Just a thought for those who may not know... I am currently using my MacBook Pro USB output to send an audio signal to a Grace m902 headphone amp with a set of Grado PS1000 headphones. The sound is quite good...
They should have HDMI. I know you can get an adapter. But why should you have to? It needs to be connected to a TV at least. Does the mini display port pass audio? I'm sure Apple will catch up at some point.
Rwwear: Yes, the mini display port on the latest MacBook Pro model does provide an audio signal.
How would HDMI be better?

Pick up an asynchronous USB or FireWire DAC and jitter will not be a concern.