A quick question: is it necessary to upgrade one's USB input into some kind of audiophile USB sound card in order to fully maximum the potential of one's DAC?
I ask because this gentleman here seemed to have done just that (or I suppose, his set-up coincided when he was selected for the review of the Dragonfly v1.2 DAC): http://www.audiostream.com/content/audioquest-dragonfly-v12-usb-digital-audio-converter
He has a "SOtM tX-USBexp" that supposedly improves the quality of the DAC.
But just how much of a performance boost does it offer any DAC, and in what manner?
It confuses me a little, as I'm quite new to high-end audio, because at first I was told that I should get a DAC to improve the sound of my headphones. Now I come across this article and it appears that not only is it enough to get a proper external DAC, you must get a proper USB input for it too. It's beginning to feel like one of those Russian nesting dolls, it just gets closer and closer to something, it's like an asymptote that never touches. Like, where is the "source"?!
Hopefully someone can explain this to me.