Mention the word “soundcard” and the picture that gets conjured up is one of geeks messing around with motherboards, tweaking this wire and twirling that one. But what if a soundcard was something as simple as plugging into a USB port of your computer or netbook and getting better sound? Well, that’s exactly what the Asus Xonar U3 is. About the size – and shape – of a pen drive and weighing little more than twenty grammes, this little beauty fits into the USB port of your compute...