Alpen is the key.... not only for regular bowel movements, but it also unlocks a super-electric-dream-highway connection between source and ears.
I bought it to use as a DAC for the optical output on my laptop when I travel. I haven't tried it on that yet. I thought I would try it between by Cowon D2+ and Yamaha EPH-100 IEMs. I have to admit, I was apprehensive on purchase, not a believer of hype, but the E17 is something else.
Currently listening to AC/DCs High Voltage, ripped from CD to FLAC. I don't really have the inclination to type reams of text describing the intricacies of how it sounds. However, as a lover of music for more years than I care to mention, I can say that of the thousands of pounds I have spent over the years on all sorts of hi-fi, musical instruments, gigging kit, whatever.... for the money, this combination is up there with the best.
My word... Nirvana's Breed just started as I'm typing. Hairs on the back of my neck standing on end? Oh yes...
The D2+ and EPH-100 are pretty good bits of kit in their own right, but while 2 was company, 3 is definitely not a crowd.
E17 - quite possibly the best £100 I've ever spent.
YMMV etc etc...