It has a gain trimming for helmets that require more punch and a "bass boost" for those who require it.
Installation is a breeze: plug the USB cable (supplied), wait for the computer to recognize it and go to the trimmings to choose the FiiO as the default output (on my Windows 7 appears as "Interface SPDIF - FiiO E10 USB DAC-"). Plug your headphones or speaker / amp and voila!
"So the sound?" you say ... Well, the difference between FiiO and my sound card (though a good model - NVIDIA / Soundmax HD audio) is more than remarkable: a lot more attack on acute, severe and very well defined impression of finesse worthy of an audiophile system. (Evaluation done with Sennheiser PMX 200)
Output "line" feeding a Creative I-Trigue 2.1 3300 there is also a clear difference with more definition and a clear and balanced sound.
Definitely recommended.