Flat out, it's the best piece of audio gear I have purchased in my 2 1/2 year long audiophile career.
My previous DAC was an M-Audio Fast Track Pro run to an external amp, so that will be the standard by which I judge the HDP. There frankly is no comparison between the two. The HDP's internal DAC is world class compared to the Fast Track Pro. It is extremely accurate without any coloring of the sound. Separation and sound stage/placement is very well produced. I get the impression that I am listening to exactly what the mastering engineer intended me to. I am starting to notice how awful some of my recordings are, this DAC will show flaws in music like nothing I have listened to before. On the flip side, I'm picking up sounds from recordings that I have never noticed before.
The amplifier was what surprised me the most about this device. The HDP has a pretty small footprint on my desk, especially when propped up with the supplied hard rubber stand. Because of its demure stature I wasn't expecting the amp to be great, but it is! In fact I have just come to notice that Jan (from Meier Audio) actually re-sells the HDP on his website - I am imagining because he's currently missing a small desktop Amp/DAC from his product line (not to mention it's a great Amp/DAC). This amp pushes my Senn. HD600s with absolute ease and I am no where near 50% of the max volume level for average listening (maybe 60-65% if I'm getting carried away). This amp has great attack and great punch and is very analytical compared to other amps I have listened to.
I think that long-term I may acquire a tube amplifier to connect to this world class DAC for when I want a warmer, more laid back sound signature, but in the meantime the HDP has found a very happy home on my desk. For $450, if you are just starting out in the Desktop world I highly recommend this device.
Equipment used for my review:
PC & MediaMonkey (FLAC and 320 MP3) :: Nuforce Icon HDP :: Sennheiser HD 600