I just got my Little Dot 2It is my first tube amp, in fact, my first headphone amp period. I purchased it with the hope of adding a little more life to MP3s off my iPod. You see, I got tired of having to sort through my collection of 500+ & growing CDs through my 300 discs player. You can see the obvious problem. So, I took a chance and ripped every CD that wasn't already (about 300) to MP3 320kbs/48,000 sample to get my music more organized and shrink my huge entertainment system. Anybody who says that a 128 or 192kbs MP3 is equal to CD quality has never heard a comparision between them through high quality headphones (high quality for me is AKG 271S, Shure E4c, UE Super Fis, and few more). At anyrate, I had hoped that the tube amp would improve the sound of the MP3's through my ipod, despite several things I read to the contrary. Read a few things that supported my idea too. At anyrate, the Little Dot 2 drastically improved the MP3s to the point I'm kicking myself for not getting the pre amp version. I did a blind test on my fellow audiophile with a 30mm Audio Technica between my Sony amp, the tube amp, and just the ipod. In three test, each time he identified the tube amp as having the best overall sound. The fact that it is not UL does concern me a little, but if you treat it like a burning cigarette, I think you'd be fine . My next thought/research will be finding better tubes, as it seems those can make or break the sound from a tube amp.