I have been intending to add my two cents or so, but the sound of the my Gungnir has continued to evolve till yesterday, so I held off a bit. It's been crunching numbers for a good 120 hours at this point, and I've had it in several situations, so I think I have a fair measure of it by now. First, I'll preface with some listening biases and a dirty confession. I listen mostly to Classical music and am one of those Luddites who believes that the measure of a system is its ability to recreate the illusion of live, unamplified music. I do listen to a wide range of pop, rock and progressive fare. Hip Hop, Rap and Electronica are not my things. My dirty secret is that I listen mostly in pen air with speakers. I haunt Head fi for the quality of the commentary on digital sources and portable music.
I fed the Gungnir via a Macbook Pro Retina using Pure Music. The computer refused to recognize the Gungnir connected directly to its USB 3.0 ports, but saw it when I connected it via a USB 2.0 hub. I got very prompt replies to my concerns from Schiit. They had not tried Macs with native USB 3.0 ports, yet, but were mystified that there seemed to be a compatibility issue since USB 3.0 should be totally backward compatible. It may be a hardware issue to take into account. However, I cannot discount the possibility that the fault may lie with Mountain Lion which is the buggiest Apple OSX that I have ever seen, thus far. Playback has been through a variety of preamps and transducers, but, mainly Symphonies Magnums, VXT 8's for near field listening and Wilson Sophias for the main system.
On first inspection, the Gungnir does nothing but impress. The fit and finish is superb, and it is solid and heavy as a billet of solid aluminum. On first listen, however ... As Doug Adams said so well, "Don't panic". It does sound harsh and strident and, well, a bit raspy out of the box. There was detail, aplenty, but at the expense of a very fatiguing high end. I turned the output off and went away for 24 hours. When I returned to listening, the top end has smoothed out a good bit and the jaggedness that a prior poster had referred to was fading nicely. It was another 48 hours till I really had time to listen, and, then, the Gungnir was a revelation. More on comparatives later. but I'll get the obvious one out of the way now. It is a CLEAR upgrade over the Bitfrost that I had borrowed. The later was nice, but the Gungnir improves on it in clarity, upper and lower end extension, and, especially in imaging abilities. Gungnir gives a very solid, but not overblown bass foundation with pipe organ pedals very firmly and cleanly enunciated. The highs are very nice and airy without the annoying harshness that I came to associate with digital in its early days. So, tonal balance seemed nailed for me, but this isn't what sets Gungnir appart from the rest, IMO. Gungnir portrays a sense of space and dimensionality of the instruments better than ANY digital source that I have heard to date. (Sadly, I haven't heard the M51, yet.) Gone is the spectacle of paper instruments on a cardboard stage. The orchestra has deapth as well as width. Instruments occupy a three dimensional space. Janos Starker's cello blooms with a body that rivals my analog setup. Concert halls reverberate and one hears the walls reflect the voices of massed choirs. Well done, indeed. What really delayed my comments is that Gungnir has another remarkable trick up its sleeve. To an astounding degree, it makes mediocre recordings sound very nice indeed. Sadly, not every great performance got a good recording, but Gungnir somehow helped me forget that and I ended up whiling away the weekend seeing what old warhorses sounded like. I've been at the audiophool business for a good quarter of a century, and this hasn't happened to me in a long time. If this is the midrange unit, I can't stand the anticipation for the reference.
On a few ballpark comparisons... Well, it was sort of sad. The Bitfrost wasn't bad, but couldn't begin to do the spatial magic that the Gungnir could. Dacmagic Plus need not apply. My venerable, and much loved CAL Tempest can't compare on the frequency extremes. My prior champ, the frightfully inexpensive Ross Martin Dual Bare Beast was also bettered, mostly in the realm of imaging and body. I am sort of looking forward to borrowing some 1k plus DACs to see how they do in my system versus the Gungnir, but I doubt I'll feel any regret returning them.
The final test, for me was to compare a 24/192 download of Janos Starker's Bach cello sonatas with the vinyl version from my collection with a table, arm, cartridge combo costing a good 10 times the cost of the Gungnir. It was disturbingly close, and the Gungnir/Macbook Pro is sure a lot less fiddly.
A couple of final notes. I did compare USB to Audiophileo 2 provided SPDIF. The later was marginally smoother, I think, but I really cannot convince myself for sure. I did not use an optical input. Cables do matter, but I'm still sorting that out. Finally, Gungnir did benefit from good isolation feet. My current fav for bang for the buck are the Tenderfeet from Herbie's Audio Lab. Good stuff.
This has been an embarrassing gush. I consider myself a pretty harsh critic of digital music reproduction, but I am rethinking that. Higher sampling rates and gear like this make the expense and trouble of maintaing turntables increasingly tough to justify. Many congrats to the fellows at Schiit. Consider me a fan boy.