DAC for 2016 MacBook Pro

Hi all, looking for suggestions for a reasonably priced DAC that I can use with a MacBook Pro running Audionirvana and that I will hook up to a WES Audio GES Amp in my office for listening with my Stax headphones. Under US$1,000.
Many thanks
 I use an Ayre Codex dac with my MBP via phasure Lush USB cable and an ISO Regen from Uptone Audio.  I listen to CDs using a Meridian player with Toslink digital out to the Codex.  The music via USB is excellent.  Just remember to remove the Mac charger while listening.

I would check out Resonessence Labs:


or  Chord Electronics:


A bit more expensive, but maybe you can find a deal or get one used.

Steve N.

Empirical Audio

Apologies for the delay but a belated thanks to all the recommendations which I am checking out.