Price / performance just perfect!

The device makes a very sophisticated look. To use it still comes as a pure headphone amplifier, powered speakers, but will follow. The sound is excellent. Because it is fun again listening to music.
Small drawback: On the first two levels of volume is the level between left and right is not the same (left loud) but it is as low as about 3 notch again equal. Generally me a stepless volume setting would be more like it, but you can see the total package that you get for the price you can safely look away over it.
The installation went very smoothly. On Mac OSX, the device is recognized as the "Speaker". Just plug in and choose the Xonar One. Unlike Windows here no driver is necessary.