Macbook Pro as source.

Well, you haven't said what headphones are on order, but a dedicated DAC would be an improvement over the "stock" mbp sound. If I understand the audio gd-fun to be a amp/dac combo, it should certainly be an improvement....what earphones will you be using? Cheers, Chris

The MacBook Pros have a surprisingly decent headphone output, really just lacking in volume available, and probably power to some degree.  With my mid-range cans, volume aside, I didn't get a big improvement from the Sparrow (the simplified version of the Fun), but the differences were more noticeable with my high-end cans.  Personally, I'd just save up for the full kit, that is, a separate DAC and amp.  You do get a bit of a compromise with a DAC and amp combined, but I haven't any complains about the Fun as a DAC -- more so the amp section which wont do justice to high-end cans such as you mentioned, though is quite listenable with them.

I would agree with getting a dedicated DAC, especially when the HD800s arrive, as they will reveal any flaws in your system. However, they really sing with a little thought put in. There might be a mbp in my future as well since I'm deciding to get more serious about computer based audio!

I agree as far as pre-Unibody MacBook Pros are concerned. The headphone output of the newer MacBook Pros is horrible: unacceptable amount of hissing, and main hum in bonus when the power adapter is connected without earth (unless you ground the chassis with your own body). I hear people say that a cheap Realtek chipset is to blame for the hissing; apparently older MacBook Pros used better chipsets by Yamaha or Sony.

 

By the way, I am also looking for a small (preferably portable), integrated DAC/amp that would work well with the MacBook Pro. I heard people say that certain USB DACs make the computer waste a lot of CPU time; which kind of USB would that be, async or adaptive? How about S/PDIF? Would I have to worry about jitter?

Edited by SwordAngel - 10/6/10 at 7:36pm

Interesting - I found the exact opposite. My 2007 Macbook Pro 15" is horrible  - the main reason I bought a uDAC. My friend's 2010 Macbook Pro Unibody 13" has no noise whatsoever from the headphone jack.
 

Haha! That would simply mean that MacBook Pros are actually very botched in manufacturing quality, from the technical point of view. Nice looks, but very unstable quality when it comes down to details. Curse you, Foxconn!

My 2010 15" MBP has a Cirrus audio chip in it.

As for small units, I wouldn't worry about jitter and all that if you aren't spending much. S/PDIF tends to be a better input but the Tenor chip-based USB input on units such as the Sparrow I reckon sounds bit better than the older and more common BB 2706/2707 that is usually found.

How does one even find out what audio chipset is used in a Mac, under Mac OS X, without opening up the case?

 

System Profiler does not say anything that specific and Apple does not seem to publish the specs down to this level of detail.

I had to remove the case on my MBP to upgrade the RAM, so I thought I'd have a look at what chip was in it.  I took a picture of it, but I can't find it.