First, Very High-Level, Impressions (Sound) …
While I’ve been running the Bifrost 2 solidly since it arrived, I’ve only gotten to spend a couple of hours with it paired with an amplifier I’m familiar with, so I do mean “very high level” impressions here:
Bifrost 2’s signature is very similar to Gungnir MB “A1” and Yggdrasil Analog 2 (think more low-end slam/impact and presence - along with markedly improved bass quality/texture, a bit “moister” overall, less-in-your-face/forthright treble, though perhaps a hair darker than either).
In terms of technicalities, it performs on par, maybe even ahead of, Gungnir MB “A2”, at least on a USB connection (haven’t tried it via S/PDIF yet), and is surprisingly close to Yggdrasil Analog 2.
The single-ended outputs are no longer second-class either, which was a factor with both Gungnir and Yggdrasil. They might measure differently, but as of right now I’m not hearing a difference.
I can see why people are referring to this as a “mini Yggdrasil Analog 2”. The “mini” part is important, both in terms of physical stature and sound; Yggdrasil still has sonic-technicality advantages - but it’s tonally very similar and a lot closer technically than I’d have dared speculate; better in some aspects in fact.
The original Bifrost MB struggled, at times, to distinguish itself from the much-cheaper Modi MB. There’s none of that here. This is clearly better than either, across the board.
Now, whether this is all more attributable to the DAC/analog stage changes, or the “Unison” USB interface, I can’t say (at least not at the moment). It doesn’t really matter, I guess, as you can’t get one without the other … and it’s overall performance that counts.
I’d say that the qualitative difference here vs. the original Bifrost MB is perhaps bigger (or at least more noticable) than the delta between the original Yggdrasil/USB Gen 3 to the Analog 2/USB Gen 5 version. Pretty impressive when you consider that this whole DAC is only $50 more than just the Analog 2 upgrade for Yggdrasil.
Lots more listening to do, and comparisons to make, in much more detail … but first impressions are definitively, and strongly, positive.