Schiit Yggdrasil -- 21 bit?


Schiit says that Yggdrasil is a 21 bit DAC. But the DAC chips that they put in the device ( Analog Devices AD5791BRUZ, 2 per channel) are 20 bit with the error of plus-minus 0.5 LSB.

How can the DAC be 21 bit if the chips are 20 bit? Using two chips per channel does reduce the RMS voltage of the noise by  a square root of 2. But how can you get to 21 bit from there?

Can someone please explain.
defiantboomerang
Thanks, David.
I just saw your response, but answered my own question earlier, right after I posed the question on here, by putting in an old ESP cord, circa 1995. I only wanted to change one thing at a time, or I’d have put the Shunyata Zitron Python on the DAC and another cord on the Arcam player. My rule, though is, One change at a time! Came back two hours later (as you probably know, cords should have time to "settle", although people scoff at that [ and I ignore that, since I KNOW that I can hear the difference between 5 minutes and two hours ]). Sure enough, it made a difference, even with a 20 year-old vintage - but quite good - cord. I’ll eventually put a Shunyata Python Zitron on it, but not now. As for the footers, I’ll do that again in a week, when I have listened to more music. Still points for now or maybe Nordost Sort Futs, althought the Townshend is - in my experience - the one that kills off the most vibration. I have used the two in combination, but not with a converter as resolving as the Yggdrasil. Since I don’t have balanced outputs on the CJ preamp (which I’m not using yet anyway), I want to give the converter every other advantage I can. Even as it is, being only 5 days old, I played Marianne Faithful’s CD of Kurt Weill’s The Seven Deadly Sins and could hear the piano pedal release waaaay back in the soundstage, something I hadn’t even been able to hear when I had a First Sound preamp or any other components I reviewed along with my own Hurricane amps (still love the realism they are capable of) years ago. Given I’m just using an NAD BEE integrated, I expect to be cross-eyed with admiration when I make that changeover.
I’ve had much more expensive digital in my home than the Yggy back when I reviewed components for TAS, Ultra Audio.com and Fi Magazine, but nothing that rivaled the Yggy in both resolution AND the musicality - and even though it’s FAR from broken in - I suspect a rather spectacular end result with the all-tubed system. I will probably buy another Townshend Seismic Platform, as I have found that to eliminate ALL airborne and structure-generated vibration. The nicest thing so far is knowing that the tonality of instruments will mature further (the upper midrange-lower treble "bite" is still apparent, but doesn’t bother me at all). Nordost’s cables take what SEEMS forever to get rid of the upper midrange glare (at least, as I’ve said in previous thread, 4 weeks 24/7).

Thanks for the response. I appreciate that.

And Gdhal, as you can tell by my response, yes, there is a rather noticeable difference when removing the stock cord. I’d suspected as much, but wasn’t sure of any conclusion until I actually did the experiment and decided that , as old as the ESP cord is, it is FAR better than what comes with the unit. I’ve loaned a friend a Nordost Heimdall cord, and I’m afraid he’s going to have to give it back it for a week or two (he won’t be happy with that, as he’s become used to the sound of his system, and he’ll notice it immediately, but hey, it’s on long-term loan to him, and he’ll just have to suck it up)! I’m pretty generous with my friends, foisting off equipment I have too much of. The only problem is that by the time I ask for it back (if ever), they’ve heard the improvement. By then, they’ve become involuntary audiophiles without meaning to! I let them hear everything I buy. This friend has heard the Townshends, both the Iso-Pods as well as the Seismic Platform and lusts after them. He’ll get one of the two eventually. But he’ll never spring for the Yggdrasil even if I take it over (and I have no intention of unplugging it, although I have an ac converter in my car, and it would take literally 30 seconds to get it out to the car. But he’ll hear the improvement, nonetheless). In fact, on Head-Fi. org, a guy decided to see how long it would take for the sound to "return." He left it off for 5 minutes and then an hour (and then two hours) and said the sound returned within two hours. Here’s his post:

"So tonight is the night. According to my very vague calculation, I was at over 1030 hours of 24/7 music play on my Yggdrasil. As promised a while ago time to turn the damn thing off. So, after this dramatic event, did music, the way I knew it, die?

5 minutes off - no sound changes really. Ok forget it, let’s do this properly.

1 hour off. Dead cold. Back to life. Right off cold the treble was a bit harsh and the rest of FR a bit disjointed. Got back to it less than an hour later (still cold to touch) and the bass, impact, speed and details were all there. The mids were butter smooth, detailed and deep reaching like before (HE-6s/Eddie Current as we know it) and the treble already great. First minutes aside, I don’t think Yggy went back to the first days’ more dubious sound. Two hours later, it’s lukewarm again and it sounds pretty damn impressive already.

I had an warmed up Theta Gen V on the side for comparison and ready to switch over to for a few days, if the sound was crap. But it’s not.

YMMV. FWIW. WTF. etc" [End of his post]



So, this might help those who are afraid to unplug it ( Me? I was FRANTIC trying to get the very stiff ESP hooked up before I "lost" the already stellar performance it delivered after 5 days!) So his post gave me hope. Mine was only unplugged for 2 minutes.

@david_ten  and @gbmcleod 

Thanks for the candid feedback regarding Yggdrasil "stock" power cords and footers. It's nice (for me at least) to understand there is yet another upgrade path and/or means to improvement. I'm more than content for the immediate future though.

While you may already know this, I figure it's worth mentioning as it's in the "same vein" where stock Yggy parts are concerned.

I've read much recently on the head-fi forum where at least some folks claim *big* improvement is to be had by replacing the stock glass fuse with other "boutique" brands (varying but all supposedly better). The downside here from what I understand is that it would void the warranty. But I suppose one could always wait a few years until the Yggy is out of warranty :)
Really?!? Schiit said it would void the warranty if someone used a different fuse???
By the way, I’m one of those people who’s used "boutique brands" since 2011 (I know you meant no harm by your statement). And they do change the sound for the better, mostly noticeable as a lower noise floor. I’ve tried Hi Fi Supremes, AMR, Horizon, Furutech, but have ended up sticking with Synergistic (I have each generation of their fuses). I wouldn’t bother changing the Yggdrasil anyway, as 1), it isn’t fully burned in and 2), I like it as it is.
As for the power cords, I eyed my Shunyata Zi-Tron sideways and wondered if it wouldn’t be put to better use in the Yggdrasil rather than the Arcam FMJ 23, which is now merely a disc-spinner. But I think not. Not for the time being, anyway.

I’m of the observation that isolation from vibration is more important that fuses, simply because, when your equipment is doing the cha-cha (and you can’t see it), the tiniest cues are missing. Even though I’ve have Finite Elemente equipment stands for years, putting the Townshend platform under my turntable, then getting the iso-pods and putting them under the amp, convinced me that vibration really does more than we realize, to the point that some of our older equipment was likely better then we knew at the time, but that was back in the ’80s, and the new hot thing then was Tip Toes! It’s odd to think that nobody considered the effect of speakers sitting on the carpet or floor (or maybe they did!). I followed TAS’ Enid Lumley, who proposed things that people - at the time - found outrageous - such as capacitors having a "memory." She was found, over time, to be right on the money about that. Then she said remove the speaker cables off the floor (did that one, too) and I even demonstrated that (it’s in another thread) for some Illustrious High End Luminaries that, indeed, Enid was right again (despite those who say they can hear no difference. That’s something I cannot fathom, having hearing loss in one ear, and I can hear it easily. Just not that very second. It takes around 2 hours for cables to settle after being moved AT ALL before you can hear the sonic changes). that’s what happened last night when I put in the old ESP cord and was chagrined to hear that the sound was "muddy." I had to remind myself to leave the room and come back an hour or two later (I usually give it two hours) and THEN, it was most decidedly NOT muddy, but a clear improvement. It makes one wonder why equipment manufacturers provide these generic cords, but then, who’s going to give away a $300 power cord that the customer might just re-sell for a profit, so, in hindsight, not so strange.

But even without all this folderol, the Yggy is quite the beast! I was happy just reading that it could be turned off for an hour or two and then it regained its magic after another hour or two. Maybe I’ll take it to the local dealer and let him listen to it. Of course, it will be plugged into an ac outlet I have in my car, so it won’t be without power for more than the 30 seconds it takes me to move it from its perch to the car (if I decide to do that).
How long did you find it took for the upper midrange glare to subside? I can hear it mostly on Mercury Living Presence recordings, since their microphones had a peak in the upper midrange and highs, but it’s clearly a bit "hashy" sounding at 156 hours. I hear - from the head-fi.org site - that it’s somewhere around 200 hours that that sound goes away. Did you experience that with your unit?

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Really?!? Schiit said it would void the warranty if someone used a different fuse???

Yes, according to folks posting here https://www.head-fi.org/threads/schiit-yggdrasil-impressions-thread.766347/page-426
See the most recent posts dating back from 1/18 to a few weeks prior.

...How long did you find it took for the upper midrange glare to subside?...I hear - from the head-fi.org site - that it’s somewhere around 200 hours that that sound goes away. Did you experience that with your unit?

Can't really say/write. I never heard anything "glaring" from the Yggy per se. It sounded good right out of the box. When I first got it I went through all kinds of listening tests from a comparison perspective to my existing gear. I documented my findings in this thread. https://forum.audiogon.com/discussions/new-yggdrasil-first-and-second-impressions

As documented in that thread, I eventually found source music material that *clearly and consistently* could be used to demonstrate how well the Yggy can "best" my Oppo and Emotiva, which now act as transport. However, I honestly cannot be sure if that discovery was a result of "break-in" or my increased understanding as to what specific qualities to listen for. I'm inclined to believe it is the later.