The Xonar Essence STU is an external Digital-to-Analogue Converter and Headphone Amp which gives the user more control over a variety options and is bound to leave audiophiles satisfied.
Design & Setup
Out of the box, the ASUS Xonar Essence STU is a sleek device that sits firmly on your desk. It comes with a stand so you can have the device vertically on your desk in order to save space. Otherwise, if placed horizontally, the padded feet occupy a larger than typical area thus enabling more stability and the padding helps absorb any possible vibrations that may come up during use.
The Xonar Essence STU comes with almost all the bells and whistles one can dream of for such a device, yet still leaving more room for improvement down the line with further upgrades from ASUS. The STU offers several ways to connect your gear to it: USB, S/P DIFF as well as analogue-In and digital inputs, which can be switched between at a touch of a button. It also comes with a headphone out, which is handy if you want to use the device for playback. In addition, there is a volume bypass switch which allows the Xonar Essence STU to be used as a pre-amp if so desired.
Mac users will be left disappointed unless playback is all you’re after as the device only fully supports Windows for the moment. Windows users have a bit more options to play with and may need to install additional drivers and reboot a few times as well as tweak some settings before the device is ready to use.
Performance & Sound
The input selector lights can be a little dim depending on how well lit your workspace is, but there‰Ûªs no problem seeing the lights in the dark however. For such a small and portable device, the Xonar Essence STU Digital-to-Analogue Converter does its job well depending on which headphones or speakers/studio monitors used in the mix.The Xonar Essence STU is a stereo device and that is how it was tested. If you like your surround sound, this device isn’t your best option.
Overall the sound quality is impressive often giving sound a more lively feel. However there’s a visible decrease in sound quality if using in-ear headphones as the DAC will distort the quality of sound received. Even if the dial is set to minimum, the Xonar Essence STU will overpower in-ear headphones and thus lead to heavy distortion of any low-impedance devices. This is likely because the device wasn’t intended to be used in such a way in the first place, instead aiming at headphones of a higher range and impedance than basic in-ears usually give you.
In general, I wouldn’t recommend using in-ear headphones or cheaper quality headphones with this device, but most self-respecting audiophiles wouldn’t be caught dead with low quality gear anyway. Also, certain headphones on the market can distort bass, which will ruin any music listening experience if these headphones are used with the Xonar Essence STU. If you’re watching TV shows or movies with the aid of the DAC, dialogue will end up distorted in parts and it can turn into a cringe-worthy experience unless you fiddle with controls and find that sweet spot where everything is okay. Uncompressed audio is where the Xonar Essence STU shows its true colors. Anything from instrumental soundtracks, classical, rock, heavy metal, and many other genres that have gone through this device in the testing phase, definitely brought a smile to my face whilst basking in crisp and balanced sound. If you thought your headphones were already high-end, the Xonar Essence STU will make them even better.
I wouldn’t use the Xonar Essence STU for audio editing, but then again this isn’t what it was intended for. Gamers and audiophiles will most likely be in heaven with the Xonar Essence STU. Overall, given the right set of headphones / studio monitors, the Xonar Essence STU does everything you need it to do, possibly more, given the right set up and conditions. It is a good option for those who don’t have an elaborate sound system set up at home, or have sub-par speakers/sound card and wish to enjoy higher quality sound without having to upgrade their gear from the ground up.