I just got back from a good sized headphone meet. I had a chance to audition a Yulong D100 and a Lyr/Bifrost combo, and of course my Nuforce Icon HDP. I tried all three set-ups with the LCD-2 as well as a Q701 (which was my second favorite at the meet, surprisingly), Paradox mod Fostex T50rp, Ultrasone Pro900, and Denon D2000. Out of all the headphones, the LCD-2 dominated absolutely over the rest with the Lyr/Bifrost combo. There was nothing that set-up couldn't do, and do phenomenally. The only thing better than it was female vocals with the Q701 and the same combo, which was mind-blowing. In fact, I'm pretty sure the Lyr with the Bifrost is the best thing I have ever heard, hands down. Although once I tested it using the Nuforce as the amp and the Bifrost as the DAC, the differences between my Nuforce and the combo became minimal. The soundstage was wider, and in general the sound was more articulate, but the highs were a bit rolled off by comparison. I won't be getting the Bifrost as of my meet impressions, since at this point it's a minimal upgrade for a $500 unit.
Yulong D100 vs. Nuforce: The Yulong isn't leaps and bounds better than the Nuforce, but I felt it was a more energetic combo. I mostly tried this with what music the Chinese gentleman - the owner of the AKGs and the Yulong - had on his laptop, which was generally electro pop, but listening to music with which I was actually familiar produced the same result. In general, the Nuforce is a bit more detailed and textured, while the Yulong is more energetic and has a wider soundstage. I would recommend it if you prefer EDM or something that calls for a more energetic presentation.
Schiit Lyr/Bifrost Combo vs. Nuforce: This one was a bit tougher. Both DACs are energetic and detailed with an emphasis on dynamics and upper midrange/high articulation. However, the Lyr/Bifrost was more dynamic with a wider soundstage. Using the track "Slam" by Pendulum, the trumpets at the beginning of the track were a bit more detailed with the Lyr/Bifrost. The mids and lows were more fleshed out, and I felt as if some details might have been smoothed over. I didn't notice this quite as much, but mmayer felt the highs were a bit rolled off with the Lyr/Bifrost. Overall, the Lyr/Bifrost pushed ahead, but not by a wide margin. The Nuforce seems to be a bit of a more laid back DAC/amp with more articulation in the lower ranges and more extension in the highs. The soundstage was a bit more narrow and might have had a greater depth, but the narrow aspect was more prominent when switching between.
Bifrost to Nuforce amp vs. Nuforce: Most of the differences I noticed with the full Schiit combo were nowhere near as noticeable as with this combo, but there was more energy and the highs weren't rolled off. That increase in energy and dynamics was the only difference that remained as noticeable as with the full combo, so I think some of that might have come with the Lyr itself. Strangely enough when I tried the Nuforce to Lyr, there was hardly a difference at all.
On a side note: if there is any headphone that is truly neutral with a perfectly clear, honest presentation, it is the Paradox. I've never heard that kind of clarity before, and it was incredibly stark. I also had a surprising revelation with the Q701s: they're glorious for extreme metal. Although they're bass lite, they have a fantastic texture and with the Lyr/Bifrost actually produce a good amount of bass impact. The Nuforce paired a lot better with them than I anticipated; I initially used them with the HDP as a joke because of how sinfully bright I thought it would be. Although with neither set up did the Q701s sound very good with electronic music, it handled most genres very well.
