USB headphone amps have gained a lot of popularity in recent years. There's a lot of good reasons for having an external DAC for audio, chief among them less noise to draw better performance from higher-quality parts, and of course more power to drive high-end or even audiophile quality headphones. ASUS has been focused on bringing interesting products based on these ideas, you only have to look at their Xonar Essence line of cards to realize that.

The Xonar brand has been around for quite a while and we love the quality of ASUS’s design and build. The first Xonar product in the Guru3d Audio Lab was the D2X, a product that I called ‘a showboat’. It was ASUS’s first top-tier gaming audio card, and of course, they made an asteroid sized splash in the market. We liked it. Then, of course, if the D2X wasn’t enough quality for you, ASUS released the Essence series of sound cards. These are the ultimate expression of what ASUS could do with audio, showing their engineering chops and, dare I say it, passion. Oh, we liked them, too. Today we have in house another Xonar, the ASUS Xonar U7 External USB sound card. It is the performance enhanced version of the Xonar U3, a thumbdrive sized USB audio adapter. The U7 is not the average external USB DAC/headphone amp. It is loaded with features, offering 7.1 surround sound audio with 192KHz/24-bit capability, 114dB SNR, line-level outputs, S/PDIF input/output, and selectable gain for those audiophile headphones you were trying to convince yourself into buying (do eet, do eeet!). While it’s not a ROG branded product, the Xonar U7 is designed to work with the ROG Vulcan or Orion headsets. But, you can use it with any headset of your choice. This means you get both a dedicated headphone amp and microphone input, in a nice external USB powered package with some impressive specifications. The U7 also has a knob. We like knobs.