Just for anyone who might be into classical and might be thinking of running a Bifrost 2 with their planers...
After much deliberation and help here I managed to secure a pre-owned Bifrost 2 to audition (seems like the only available Bifrost 2 in the UK?) and was really looking forward to seeing how it improved on my little Soncoz LA-QXD1 I am looking to upgrade. I've read all the reviews so was expecting the R2R type 'realness' yet still an open airy top end, what I got in comparison to the Soncoz was a more deliberate presentation, not at all unpleasant, but something was definitely lacking. After lots of swapping backwards and forwards (both units had been on and playing all morning so nicely warmed up) I realised I needed to get serious because what I was hearing wasn't what I was expecting from a £199 vs £720 comparison.
So I organised a Roon group and connected both DAC's via USB to identical P4's running Ropieee so all I needed to do was mute and swap the RCA's to my Rebel amp between each listening. I really wanted to hear the better and more expensive DAC make a clear case for itself, but it definitely didn't do that. First of all I'm not too sure why Schiit make all this fuss about their USB input, its ok, so is the Soncoz - but coax had the slight edge via the Allo DgiOne HAT (when I tried that in desperation trying to find the Bifrost's best side!). I was expecting Unison to improve the Pi USB as that's what I presume it is for, but it seems the Pi4 USB is quite fine enough anyway.
Listening to a varied selection of music it was hard to put my finger on what was missing when I switched to the Bifrost, certainly everything was there, just put together a bit differently. So I resorted to exclusively comparing the two with the music they will be used to listen to, classical, and chose a favourite Sibelius symphony with lots of texture, rumble, massed strings and the works. Here it became obvious the Bifrost was not resolving the same kind of detail the Soncoz was, you could say the Soncoz was just less subtle and sharper in the treble, but it was more than that. In passages you would consider fillers leading to the main deal on the Bifrost, the Soncoz delivered those subtle audible 'build up' clues that made the hairs on the neck stand up. The bowing texture of massed strings for instance was really obvious, it was clearly lots of strings and lots of bow hairs. When switching to the Bifrost however the same sounds were most definitely there, but the texture and detail was recessed. I'm not going to use words like smeared or rounded off as that's not the case, but for classical music the way the Bifrost put those digit back together made whole sections of the piece uninteresting to listen to, subtle clues were not presented as the finer details were absorbed into the mix. Maybe there is a case to be put for delivering all the data without prejudice in the way these modern delta sigma DAC's do, leaving the ears to pick out what to focus on - even though I am and always will be a fan of manufacturers that go a different route and bring some organics into their designs.
What I am describing is most likely the expected multi-bit effect, and I am sure if you weren't comparing with a typically clean and clear delta sigma DAC and you were perhaps making a better case for the Bifrost with the type of music you were listening to (several reviewers have said its so much fun on dense rock and electronic) all would be hunky dory. I have experience with R2R DAC's in the main system and always the difference is more about 'reality' and the tonal representation, detail is there but its less digital and more 'real', maybe for that you need a proper resister ladder and not a multi-bit chip? The real eye opener however is how the little baby Soncoz stood up and delivered such a performance that I can now look upon with greater respect! Today it seems great DAC's start at £100 (the little Topping E30 I had also punched well above its weight!) and the difference as you go up the 'ladder' is not what you might expect!
I might try the Soncoz SGD1, not for vast improvements as I wouldn't expect that now, but maybe for more of the same Soncoz style with a little bit of layering, placement and depth information possibly? Its fun and its my hobby, and I dare say I shall have dozens of DAC's and amps and headphones before I slope off into the big hifi show in the sky, but what an interesting time to be buying electronics! I am not of the ASR opinion that all DAC's sound the same and that measurements are all, but certainly the quest for great measuring DAC's has levelled the playing field don't you think? Plus getting that synergy right with different methods of delivering those digits and matching that with appropriate amp and phones is a lifelong pursuit.
Just thought I would drop my findings here, your mileage I am sure may well be different as not only do we have different systems but more importantly different ears!