You can also use the MacBook Pro's optical audio out. It doesn't look like it has one, but if you buy an adapter for the audio out jack that converts 3.5mm to optical, then you can run the optical cable. This is what I'm considering.
3.5mm to Optical adapter
I too am considering the Little Dot DAC I. I emailed Dave (or David) at Little Dot and he told me he was working on another DAC but it's still under development not to be released for some time.
I was hoping to use my MacBook Pro with FLAC or Apple Lossless files through the optical cable with the adapter to the Little Dot DAC I, then buy XLR cables to route the the Little Dot MK VI+, then route through balanced headphone cable to the LCD2.
I have none of these components, this is just what I'm scheming up. This whole solution I think would cost just a little over $2000 and for a balanced setup, a nice tube amp, the arguably the best headphones on the market, and a pretty good DAC. I know you could improve on the DAC but come on, for under 300 you get optical/USB input, balanced outputs, a Wolfson DAC. That's a pretty good value in my book. The only issue with the DAC is that it's prone to upgradeitis.