Need some basic DAC assistance for MA8900

[Reynolds617]

Hi folks:

Purchased an MA8900 a few months back and haven't really paid much attention to the DAC since I frankly didn't really understand what it was (noob alert). In any event, I've been playing vinyl, CDs and streaming Spotify from my MacBook Air.

My question is, what's the best way to take advantage of the superior DAC in the amp to get higher quality audio from my MacBook (and possibly the CD player?)?

I have headphone out on the MacBook and a USB.

Any advice for how to achieve this would be greatly appreciated, and I apologize in advance if this is a real greenhorn question.