Cause of different sound between dacs

"I was hoping for a simpler answer and a simple way f
of making sensible choices."

Listen to them both and pick the one that sounds the best.

That's too simple.

"08-31-13: Mapman
That's too simple."

I know, but it works.

Grannyring(Bill),
Yes! The power supply and the quality and implementation of the analog output section are huge factors in determining the sound you'll hear. Bill I seconded the high quality active line stage suggestion and I know you've tried direct DAC options, welcome back.
Charles,

I am not able to audition the two. Perhaps someone with experience can comment?