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
@cleeds 

A hobbyist group is fine, nobody objects to that. But being a hobbyist does not mean that anything goes. In particular, sighted listening is useless to judge sound quality. Blind tests are a but better, but to seriously judge audio quality, one must measure.
defiantboomerang
A hobbyist group is fine, nobody objects to that.
Some here have objected - very loudly - and they have insisted on scientific data to accompany observations. That's just silly on a hobbyist site.

 But being a hobbyist does not mean that anything goes.
Of course. These forums have rules, as established by Audiogon. Those rules govern the site.

 In particular, sighted listening is useless to judge sound quality.
That's opinion stated as fact.

Blind tests are a but better, but to seriously judge audio quality, one must measure.
Surely measurements have their place. But most of the great audio designers insist that listening is also important. Listening and measuring are not mutually exclusive.

I suppose you’re overlooking that Atkinson NEVER played the Yggdrasil to hear what it actually sounded like.
Solid state used to have ’perfect measurements,’ but it sounded crappy. I just listen: and I hear (and play) instruments a LOT, so I don’t care what measurements say. My ear tells me what sounds closer to real. I’m surprised at the if-it-measures well- it’s-going-to-sound-like-real -ife. I’m hear to tell you it doesn’t. ( I now play piano, flute, harmonica). If you don’t here live music, you know less than you think you do. You’re unfamiliar with what it live (unamplified) music sounds like. People nowadays (and I suspect they’re younger) compare technology as a means of predicting how a component will sound, instead of realizing they really need to hear live music. When you hear it live and then hear it reproduced "perfect measurements" or not, you know what’s better. How many of you hear live, unamplified music often? I’d wager, not many. You can’t measure ambience or "air": you need to have sufficient experience with live music to know that. Sound like most people here haven’t ever been in a symphony hall. What nonsense to think measurements are dependable. Feh!
It’s interesting that so much of the time, people look at the specifications. A spec willl tell you absolutely nothing about how something might sound. (Moffatt was one of the designers on the old Theta, which, in its day, was lauded at "THE digital component to have), so I think he knows just a teensy bit more about digital sound than most people on this forum. But I do understand people not wanting to have something that they THINK will not give them superlative sound. I went ahead and purchased the Yggdrasil. It hasn’t even arrived yet, but If it doesn’t resemble live music - which I grew up with - then I will simply return it. So much easier than the constant "tsk, tsk-ing" that we resort to over the Internet - without ever having heard the component in question. And ever since the rise of the Internet, I've seen more comments by those who know nothing of the component in question, yet position themselves as experts of a sort. That way lies madness.

I remember when the JVC XL-Z1010 CD player came out, back in 1991. At the time, it cost only $700. There were many other much more expensive machines around - and they ALL reminded me of digital sound, while the JVC sounded -eyes closed - like real music (even with its faults) . People seem to be stuck in reading specs. Use your ears, mates. That’s what they’re for. I don’t even understand (nor care to) read arguments about "it only has 20 bits instead of 24". Instead, I know what’s good and what just sounds good to less experiences ears, because I (fortunately) get to go to Carnegie Hall or The Met. My goal, before I die, is to hear a concert in the Musikverein, the (acknowledged) best hall in the world. I know what live music sounds like, and that’s my reference. Whatever comes closest to (any one of) those halls - plus other halls I’ve been to - tells me how much of "the absolute sound" a component achieves. Shouldn’t we all be thinking of that? Well, unless you aren’t able - or never go to the symphony or ballet or opera and are unfamiliar with the actual sound of live instruments. I can easily understand, then, why, instead, people endlessly debate about the technical merits of things. And, of course, if you have SACD discs or whatever else there is, then you might be apprehensive when reading reviews about the poor Yggy, which can only do "basic" digital. Doleurs, Doleurs...

But, having written for several magazines for a while (TAS and Fi among them), I finally learned specs mean nothing, just like hearing the ingredients in a recipe cannot tell you what it will taste like (but it CAN give you a vague idea, based on the ingredients used). But then, that was back before the Internet, where people and intellectually debate how "bad" something must sound because it doesn’t have the maximum - or the best - specs. I’d go crazy reading if all I did was read - and listen to the it-can’t-possibly-sound-any-good. I used to hear that about my WATTS, and my Quicksilvers, and even some of my (obsoleted) PS Audio components. Since I know what a french horn sounds like, or a cello, I can just listen. It’s easier! If you don’t know what live sound sounds like (even in different halls), you can really have a hard time of it. But a forum is no substitute for knowing what actual instruments sound like. And, of course, on pop recordings, most of which elicit a dismayed "oh, man!" reaction from me, it’s hard to know anything about which digital machine will deliver the goods. But on a simple Rega turntable, I can tell instantly. Funny how the digital equipment people have elicits disdain from others who point out its shortcomings (without ever even having heard it for an hour or two). And i owned tow well-respected DACs, which sounded great - but not much like live music, so I have to smile when I read people saying "everyone just likes what they like." No, maybe some people do, but I’d wager they don’t get to concerts halls of unamplified music much. I’d sooner be impaled by a Jedi light saber than debate digital. After all, eggs are eggs, but if you use them when they’re cold, your cake/pie/souffle is NOT going to be - as they say in the Army ads, "be all that it can be." Perspective, perspective.

I’ll just see how much the Yggdrasil resembles Carnegie, or even Davies Hall in San Francisco (where I used to live). That will tell me all I need to know. But for only $2300, if it surpasses the Audio Research digital equipment my local dealer has, it’ll be placed on the Townshend Isolation platform - and there it will stay. (I don’t think it will shine even in his $100k+ system for one reason - he can’t set up a good system to save his life, so I’m not using his system as a "reference." But I’ll still benefit from hearing his DAC and mine side by side, just to see where his shines (and my Yggy doesn’t).
As for the person who said, "who’s Harley", he’s the Editor in Chief of The Absolute Sound and has been reviewing for 25 years or so. And has reasonably good ears, but has DEFINITELY heard more components than this entire forum combined.
@gbmcleod   Looking forward to hearing about the Yggdrasil and where it falls for you. I have found it responds well to isolation, so your use of the Townshend platforms will help stretch it's performance. If you are using the USB input, make sure you get the Gen 5 board installed, should yours be an older unit. Holiday Cheer!