suggestions for updating via DAC.....

Im looking to upgrade my system, and thought a DAC may be the way to go, since I still listen to a decent amount of CDs (I do have a bit of music on my iphone (although at lower resolution)). Any suggestions for a DAC at 2K or lower? Or any suggestions for bettering my system another way? I'm open to suggestions.

My system:

musical fidelity a3c amp and pre-amp.
martin logan aeon i speakers
NAD 542c cd player
music hall 7.1 turntable with clear audio virtuoso wood cartridge

THANKS!!!