Good looking little cute machine. The two knows can hide "old mud" . It is more/less like a good quality sound card plus head amp, the way it is build. Using op amps instead of traditional transistor circuits. It could be good though. Would be even nice it is a full function pre-amp.
ASUS is getting better and better. You should review the Xonar Essence One. It got high review from 6moon. It allows you to swap different Op-Amps for tonal preference. Interesting the lower model Essence STU also has this option but not the E3.