Schiit Happened: The Story of the World's Most Improbable Start-Up
Oct 4, 2014 at 2:23 PM Post #2,956 of 72,756

Stereolab42

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For DSDx1, this noise starts to rise shortly after 20kHz and starts to peak around 40-50kHz. So much for DSD as "hires" because for DSDx1, 30kHz to 90kHz is dominated by such a high noise floor where there is little dynamic range, at best a few bits.

 
Yes, I think most DSD proponents are in agreement that DSD128 is where the sweet spot is, since the shaped noise only begins way past 40khz there.
 
In the end, the math is only going to tell you so much. One must approach a format like DSD in the same way one approaches tubes and vinyl, believing that it's special because it has one foot in the analog word. It will probably always be niche, but so are tubes and vinyl, which many here appear to be fans of. Anyways, I've made my point, and don't want to detour the thread anymore, so I will sit back and await Jason's next chapter.
 
Oct 4, 2014 at 2:28 PM Post #2,957 of 72,756
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Thanks for responding. Regarding ADCs, I'm referring to this post and the posts surrounding it. It seems like the only ADC with a native PCM front-end has been discontinued, so they are all at least multi-bit PDM, and many single-bit PDM. (I don't understand the distinction between multibit delta-sigma and PDM, I've always seen the terms used interchangeably.) So it seems to me the purest audio chain is had by taking a 1-bit PDM ADC and directly sending the output to a DSD file, which appears to be what many of the audiophile DSD labels are doing (either using live music or analog tape masters as sources).
 
And I guess one can argue about the algorithmic complexity of the noise-shaping/feedback loop in the ADC, but when considering playback, DSD surely is substantially more "analog" than PCM. Here is a quote from Paul McGowen of PS Audio.
 
"Here’s the interesting part of this: if you take a DSD stream and run it through a simple analog lowpass filter to smooth out the on/off transitions, you get music!  This is amazing considering that if you do the same with PCM you get only noise...
DSD is a lot closer to analog than PCM ever thought to be."

Of course as you point out, to get the best music the playback circuit isn't quite that simple. But it does produce music. To me, that's very special and even a bit magical, for a file that can be stored as a stream of bits on a hard drive, just like PCM.

And I don't think the DSD to HDCD comparison is fair. HDCD had a strong corporate-pushed beginning, a brief peak and then a quick death. Apparently it was just a variation of PCM, in some proprietary format, nothing really exciting about it. DSD, in the form of SACD, also had a strong corporate-pushed beginning, a brief peak and then appeared to die... but with the birth of high-end computer audio was resurrected, and has been gathering lots of momentum in the few brief years that affordable USB DSD DACs have been around. And as discussed above I think it's so fundamentally different a format that there are plenty of reasons for people to get truly excited over it. We will see if the train keeps gathering steam.


I don't want to continue the DSD discussion endlessly, but I do have to disagree with the "magical" aspect of its playback, and in Paul McGowan's interpretation of it as being "closer to analog." I have the greatest respect for Mr. McGowan, but we definitely differ on how we view DSD.
 
While DSD can be viewed as audio by looking at it with a low-pass filter, this has nothing to do with magical qualities, and everything to do with the computation-intensive noise shaping done at the encoding phase. A 2.8MHz bitstream (or 5.6, or 11.2) has a wideband signal to noise ratio of 6dB, which is a mathematical fact. This can only be reduced in the audio band by computation that pushes the noise out of band, as explained in Stanley P. Lip****z and John Vanderkooy's AES paper:
 
Why One-Bit Delta Sigma Conversion is Unsuitable to High Quality Applications 
 
The abstract: "Single-stage, 1-bit sigma-delta converters are in principle imperfectible. We prove this fact. The reason, simply stated, is that, when properly dithered, they are in constant overload. Prevention of overload allows only partial dithering to be performed. The consequence is that distortion, limit cycles, instability, and noise modulation can never be totally avoided. We demonstrate these effects, and using coherent averaging techniques, are able to display the consequent profusion of nonlinear artefacts which are usually hidden in the noise floor. Recording, editing, storage, or conversion systems using single-stage, 1-bit sigma-delta modulators, are thus inimical to audio of the highest quality. In contrast, multi-bit sigma-delta converters, which output linear PCM code, are in principle infinitely perfectible. (Here, multi-bit refers to at least two bits in the converter.) They can be properly dithered so as to guarantee the absence of all distortion, limit cycles, and noise modulation. The audio industry is misguided if it adopts 1-bit sigma-delta conversion as the basis for any high-quality processing, archiving, or distribution format to replace multi-bit, linear PCM."
 
This paper specifically addresses 1X DSD. 2X and 4X DSD address some of the shortcomings outlined in the paper, but as you know, 2X and 4X DSD recordings are very, very thin on the ground, and the number of 2X and 4X DSD recordings that remained DSD all the way through processing is markedly smaller. The link regarding three new ADCs that support DSD recording does not address the fact that the output of the vast majority of studio ADCs is PCM, and that most all studio processing is done in PCM, so any DSD recording is likely to be of mixed provenance, unless taken directly from a single-mic recording feed, or taken off of original master analog tapes (which have their own issues with noise.)
 
It's important to note that this is not a screed to tear down DSD, it is just to try to show there is no magical "direct to the source" format. Similarly to DSD's provenance issues, most modern PCM recordings go through an intermediary multibit delta-sigma stage within the A/D converter before being output as PCM, and (these days) are usually converted to a multibit delta-sigma output as part of the D/A conversion process. Records go through RIAA equalization and are completely dependent on the mechanics of the cutter used to make the master pressing, as well as the quality of the vinyl, the quality of the cartridge, the quality of the phono preamp, etc. 
 
If you're interested in delving more into the grey areas in PCM vs DSD, arguably the best comparison of DSD to PCM at the current state of the art is here, done by Charles Hansen of Ayre:
 
World’s First Valid Comparison of PCM versus DSD 
 
So what does all this talking get us? In the end, we have different philosophies.
 
DSD advocates believe that upending the entire recording chain (and somehow maintaining DSD through the chain) with playback through a pure DSD DAC will end up creating audio nirvana. It is important to note that most DACs that play back DSD actually (gasp) convert it to multibit delta-sigma during the D/A conversion process, so they are not pure DSD.
 
We believe that the widespread use of multibit delta-sigma D/A converters, as well as the use of mathematically intrusive strategies such as asynchronous sample rate conversion and open-form digital filters has limited the capability of the PCM format. As with DSD, only a handful of PCM DACs actually use R2R D/A conversion, so it is not pure PCM.
 
So, two different philosophies, two different approaches. We'll see if we can get closer to the original with Yggdrasil, and other companies will see if they can get closer to the original using DSD.  We'll see what the listeners say when they're both fully realized.
 
In the end, the market will likely shrug at both, since, by and large, it will be streaming compressed music via monthly subscription, rather than buying 2X DSD or 24/96 PCM. 
 
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Oct 4, 2014 at 2:34 PM Post #2,958 of 72,756
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How a recording was made, processed, and mastered matters more than the equipment. 

 
Boom. This.
 
The DSD/PCM war can be viewed as nothing more than a distraction, keeping us from addressing the elephant in the room: recording quality.
 
And that's my final word in the matter (at least until next week, since the chapter deals with Yggdrasil and "digital today.") I believe I've covered a lot of the content there in commentary, so again, apologies if this seems like a rehash.
 
Schiit Audio Stay updated on Schiit Audio at their sponsor profile on Head-Fi.
 
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Oct 4, 2014 at 2:52 PM Post #2,959 of 72,756

Ableza

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Also, math = magic for those who don't understand math. 
rolleyes.gif

 
Oct 4, 2014 at 2:59 PM Post #2,960 of 72,756
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  Also, math = magic for those who don't understand math. 
rolleyes.gif


Considering how I felt about differential equations (before getting into S, jw, and Z simplifications), I can totally understand this.
 
Schiit Audio Stay updated on Schiit Audio at their sponsor profile on Head-Fi.
 
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Oct 4, 2014 at 3:02 PM Post #2,962 of 72,756

Ableza

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  . It seems like the only ADC with a native PCM front-end has been discontinued

Not sure what you mean.  There are plenty of ADCs out there in the pro audio world and they all use PCM encoding.
 
Oct 4, 2014 at 4:59 PM Post #2,963 of 72,756

senorx12562

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"In the end, the market will likely shrug at both, since, by and large, it will be streaming compressed music via monthly subscription, rather than buying 2X DSD or 24/96 PCM."
 
Boom. This. (Back at ya Jason).
 
Factors other than sound quality, like convenience, cost, portability, and others, will always trump SQ for a majority of the market, Especially cost. Thus the success and inevitable dominance  of the subscription streaming model of selling music. And the inevitable eventual failure of DSD as anything other than a (very small) niche market. $25 an album for a download? Not including the people who frequent this site and others of its ilk, I'd wager that the majority of the market won't spend much more than that on their headphones (which of course means that they couldn't tell the difference anyway). The number of people for whom SQ is the most important consideration is vanishingly small, and maybe just vanishing. Sad but true I'm afraid.
 
And as for vinyl, when CDs came out, I was overjoyed that vinyl was seemingly going the way of the dinosaur the remains of which were used to make it. Eventually, after one move, my old Harmon Kardon T-60 was never unpacked, and the 4-500 albums stashed in a closet and mostly replaced with CDs. Then when I became aware that many (most?) audiophiles at least claimed to prefer the sound of vinyl, I was like "Hey, I have some of that, what am I missing?" So I got out the TT and the albums, only to discover that my modern receiver didn't have a setting with enough gain to play albums, so I had to go buy a phono pre (NAD pp2). So I get everything set up and settle in to listen to some albums, waves of nostalgia rolling over me, only to discover that I still preferred the sound of CDs, even to the MFSL half-speed mastered, 180gram virgin vinyl editions. No surface noise, don't have to get up every 20 minutes (30 if it was a Todd Rundgren album), better dynamic range, all the reasons I fell in love with CDs in the first place. Now maybe my equipment is too crappy to get the best out of vinyl, but I've always had the best equipment I could afford and I'm not getting any richer, so that won't change. Needless to say, my TT is in a box again, and everytime I move I want to just leave the albums, but so far I can't bring myself to. I checked ebay, and a T-60 was going for $250.00. Hmmmmm. It's like old muscle cars, people have a thing for them, but the truth is that a modern Civic Si will probably blow its doors off, especially if there are any corners involved, and is three times as efficient. 


 


 
Oct 4, 2014 at 5:06 PM Post #2,964 of 72,756

smitty1110

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Considering how I felt about differential equations (before getting into S, jw, and Z simplifications), I can totally understand this.

Try explaining group theory to people, or topology. I did a little sketch of a proof to my coworkers the other day with group theory to show how individuals and households for ads are related, and how to generalize to higher levels, and it blew their minds.
 
Oct 4, 2014 at 9:54 PM Post #2,965 of 72,756

valiant66

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I have a DSD capable DAC. It's pretty unlikely that I'll ever purchase any DSD music. I might download the samples on the Oppo site. Or not....

 
So... since you're unlikely to buy DSD music, why did you pay the (I assume extra) $$$ for a DSD capable DAC?
 
(I don't mean for that to come across as confrontational, I'm honestly curious.)
 
Oct 4, 2014 at 10:02 PM Post #2,966 of 72,756

valiant66

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  ...as explained in Stanley P. Lip****z and John Vanderkooy's AES paper...

 
Ha ha ha ha HA! LOL. I never put it together that Stanley P.L.'s name might tickle the bbs censor! (This is in reference to your company name having an extra "i" for just that reason...)
 
Very funny. I almost never LOL in text, but I had to this time because I really did. The cat ran away in shock... :wink:
 
Oct 4, 2014 at 11:55 PM Post #2,968 of 72,756

Vansen

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Boom. This.
 
The DSD/PCM war can be viewed as nothing more than a distraction, keeping us from addressing the elephant in the room: recording quality.
 
And that's my final word in the matter (at least until next week, since the chapter deals with Yggdrasil and "digital today.") I believe I've covered a lot of the content there in commentary, so again, apologies if this seems like a rehash.

 
I roll through most of my [work] day with my CIEMs off my iPhone. I constantly think to myself, "this could have been recorded or mastered better." However, at the risk of being lynched, I can't really recall many times that I thought, "I wish I would have ripped this album as lossless instead of MP3."
 
Oct 5, 2014 at 12:31 AM Post #2,970 of 72,756

tonykaz

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Since When ?  
  Over all the years of Music Reproduction we have never had access to an Established Component Designer or Manufacturer ( perhaps NwAvGuy being the exception ) , especially one that pulls back the Curtain to show how the magic is created and built .  Or the same person fielding consumer interest related issues in any kind of Public Format .   
  This is kindred to having our own Steve Jobs sending us notes about Industry related tidbits . 
  Quite an education .   We probably should be paying Tuition !  or continue to buy Schiit Products ( what I'll do ) .   
  As a manufacturer I'm concerned with the Big Glossy Rags supporting promotional pushes by the Marketing groups trying to kick-start support for DSD , Vinyl or some other deJour idea ,  triggering Buyer Remorse and mis-trust issues .  We call this sort of thing "Burning the Customer" ! , manufacturers share the blame here but pressure from Sales Teams can get intense , stuff like DSD creeps in and causes problems .  
A well informed buying public is a good answer to mis-direction in the marketplace .
 I am pleased that Jason Stoddard is guiding thru these tricky issues , where are all the other manufacturing designers and why aren't they offering some thoughts and insights ?? , Seminars at RMAF are not enough , clearly .
  We have the Internet and forums like this , maybe we should petition people like the quoted Gordon Rankin and others to participate , it is the 21st Century after all , the market Pie is just getting bigger every day , we need qualified people to clear the air properly .
Tony in Michigan 
 

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