Macbook vs Squeezebox 3

I am actually in the market *right now* for a USB cable upgrade, and this is my short list, in case you're interested:
Kimber USB and USB AG
Audioquest Carbon
DH Labs USB cable
LAT International USB cable
Cardas USB Clear
Wireworld silver starlight
Ridge Street Audio Poiema
...still gathering information, also looking at digital cable upgrade, will add Acoustic Zen Silver Bytes...

I'd just stick with the SB until it's no longer usable. Eventually, you may not be able to use the streaming services that use mysqueezebox.com, but streaming local files should work forever, as long as your OS on the server remains compatible with LMS. I have saved copies of LMS for backup.

"Are you saying that I will not be able to get sound that equals or betters my Squeezebox, from my Mac, without a USB converter and an expensive digital cable? It seems like the converter is the more important piece at this point?"

Yes, that is what I am saying.

"Before putting a lot of money into this, I am going to try the Musical Fidelity V-Link, to see if that improves things at all. Do you expect that this set up would bring the Mac closer to the SB3?

I would expect it to beat the Mac Mini alone.

This is like buying a phono cartridge. A good one will sound better than a cheap one, but the expensive one gets you the live performance.

Think about this: if the source is compromised, there is not much you can do downstream to fix that.

Steve N.
Empirical Audio

I had a similar revelation with a Bolder Modified Squeezebox Touch and a Macmini I purchased with thoughts of replacing it. I ultimately decided it wasn't even worth the effort of modifying the macmini as the SBT had such an advantage and the modifications for the Macmini were significantly more expensive vs. my sunk cost.