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

Eastern Electric MiniMax DAC. With a little op-amp rolling and tube rolling, it's hard to beat. I love mine.
IMO the two DACs to beat in the sub $2000 category are Metrum Octave and Teddy Pardo DACs. The first one is more transparent and direct sounding, the other one is more smooth and analog. Do a google search on both.
It would be helpful to know what you are missing with the NAD?
A few years ago I owned the C541i and thought it was great for the $.
An Audio Note 2.1 kit DAC can be had, meticulously built by Pete Fulton, for under 2k, possibly a 3.1

These DACs are non-oversampling, tubed, although limited to 18/96, but imo are extremely hard to beat at their price level. The sound is liquid, relaxed, analog-like, extended, with excellent dynamics and 3-dimensionality.

I recently heard the EE, but have not heard the Metrum. The EE is nice, but does not compare imo to the AN DAC.

I am not in any way business-related to Pete Fulton (digitalpete) but a very happy customer of 2 of his DACs, and have talked to other happy customers of his. Also, I've owned 3 AN DACs and have always come back to them after trying others.
My suggestion.

Buy a Mac Mini, a Wyred4sound DAC 2 (asynchronus USB + pre volume control) and never again fight with disc transport limitations. Probably closer to $2200 but now you can step into 24 bit HD downloads.
"Buy a Mac Mini ... and never again fight with disc transport limitations."

Instead struggles with system configuration, internal CPU noise and the hassles of downloading your CD collection.