That would work fine if I wanted that (in fact have done that, and it is fine). But it is not what I am talking about.
Either late at night, or out on the go, I want to be able to use a good pair of headphones, and plug into a good high-quatlity sound source - namely a portable DAC like the Oppo HA-2, or a digital player with a built in high quality DAC, like the Fiio X3 or X5, to play cd quality or higher flac files.