Powering Monitors: Dedicated DAC or Recording Interface?

I need an external, USB DAC that can control a set of powered studio monitors. Something simple that goes between my computer and the monitors and lets me control the monitor volume. I have no need for recording or mic inputs or any super fancy bells and whistles. This is for music playback only.



Requirements would be:



USB input from computer

Balanced XLR or TRS output for monitors

24bit/192k processing

Output/monitor volume control



A phase reversal for the monitors would be awesome. But not required.



Does it matter if I go with something like the Focusrite 2i2—which is more of a recording interface with mic pres (that I'd never use)—or something like the Cambridge Audio DacMagic Plus—which is a dedicated DAC?



The new Roland Super UA looks interesting too.



Thanks!

Powering Monitors: Dedicated DAC or Recording Interface?