[Ableza]

 
Fair, but come on, for several years Schiit was quite happy to sell D-S DACs, so it is somewhat disingenuous to suddenly start saying well, that was a crap technology, we have moved on. Nobody is questioning the skills or knowledge of MM, nor the prowess of the Yggy, quite the opposite actually. What some of us are saying is that regardless of the technical level of discussion how things sound being a very subjective field means that there are actually people who like the D-S signature, and again, I have yet to read of any blind listening tests that demonstrate that any R2R DAC is consistently preferred by listeners. I will say again, I have no opinion yet on the matter beyond having an open mind. I think the M51 for instance sounds quite good, I actually like it very much. Now it is very possible that after hearing the Yggy I will be saying something very different, but perhaps not.

Like I said, to each his own.  No one should be arguing that any technology is the "be all end all."  If they are, they are foolish.  All I said is I will take Mike Moffat's opinion about what he thinks creates the technically best DAC over yours or anyone else's, and after I gave his solution a try I will not go back.  In fact I am planning to buy at least one more Yggdrasil.

 

[coli]

You keep talking about that "superior R2R approach" and you do not give a single freaking *argument* for it ... neither technical, nor sound tests/comparisons/etc ... nothing, nada, zilch.
Sorry man, but for all I know you could be just as well talking unicorns. Could you please add *something* to support those R2R claims !? I'm not picky, I'll take *anything* ...

Faith man! Your faith may vary.
 
Edit: I have read that multi-bit is more resistant to jitter.

 

[evillamer]

Have you guys seen the scope output on this page:
http://www.mother-of-tone.com/conversion.htm

 

[Argo Duck]

Fair point but there's a sample-size problem here. I understand there's a much larger pool of DS than R2R dacs. Selection from the smaller pool is more likely to result in sampling error., i.e. we're less likely to learn the 'true state of the art' with R2R.

Not to mention that there is presumably a greater variance in the quality of engineering solutions with R2R, simply because it's the less commonly taken path and less engineering 'know how' is available. (Disclaimer: I'm no engineer and could be well wide of the mark with this statement!).

Great to hear your Yggy/M51 trial is coming together S-D.

...yet to read of any blind listening tests that demonstrate that any R2R DAC is consistently preferred by listeners...

 

[Jose R]

  Yes, I was basically talking about "current production chips". The TDA1387 is a 16 bit DAC chip, which would disqualify it for most "current designs" - since these days a DAC that can't handle 24 bit signals would be a niche market item at best. The TDA1387 also doesn't appear to support oversampling internally, and this leads me two conclusions- depending on how you implement it. If you don't use oversampling, then it's going to be very difficult to design a reconstruction filter that is sharp enough to remove what it has to, yet avoids significantly altering the audio frequency response. (In that situation, I would expect the reconstruction filter to have such a profound effect on the overall sound quality that it would completely overshadow and differences in the DAC topology itself). If you DO use oversampling, it would have to be external to the DAC, and you would have to design and program a custom oversampling filter, in which case I would expect the sound of THAT to overshadow the inherent sound of the DAC topology.
 

 
 
So, in essence the TDA1387 is the typical junk-pile DAC chip for those not concerned with sharp rolloff at 17Khz.
 
 

  Keith:
 
Hello and glad to see you posting here on Head-Fi. 
 
I'm a long-time Emotiva fan and have been supporting Dan Laufman since the early days.  But I will trust the design decisions made by Mike Moffat over yours or Lonnie's or mine or, well, over pretty much anyone's when it comes to DACs.  As a long-time Theta-luster I was very excited when I first read about the Schiit Yggdrasil and as a first-build owner I am happy with both the performance and the price point they obtained.  The two Emotiva DACs I have owned both left me wanting more (although I have not heard the Stealth.)  Whether this was about topology or execution or digital interpolation schemes and sampling algorithms I don't know nor really much care.  I just know what stayed in my rack and what was re-sold on Fleabay.
 
As in all things audio, to each his own, but when it comes to design I'll stick with the word of the engineer who invented the market sector.

 
I own the Stealth DC-1 and I am having a hard time convincing myself to upgrade to the Schiit Yggdrasil or the Auralic Vega. It does everything I need it to do, all the inputs/outputs I need, a well implemented volume control,  and sounds pretty damn good too. It is smoother sounding than my ESS Sabre Dac (EE Minimax Junior), but both of these units offer great value at their respective price points.
 
The DC-1 is just exceptional.

 

[Tuco1965]

So, in essence the TDA1387 is the typical junk-pile DAC chip for those not concerned with sharp rolloff at 17Khz.



I own the Stealth DC-1 and I am having a hard time convincing myself to upgrade to the Schiit Yggdrasil or the Auralic Vega. It does everything I need it to do, all the inputs/outputs I need, a well implemented volume control,  and sounds pretty damn good too. It is smoother sounding than my ESS Sabre Dac (EE Minimax Junior), but both of these units offer great value at their respective price points.

The DC-1 is just exceptional.

Leave Head Fi and enjoy your gear. I say that meaning that you seem pleased with what you have. Put the wallet away unless you're buying more music.

 

[blasjw]

   
 
So, in essence the TDA1387 is the typical junk-pile DAC chip for those not concerned with sharp rolloff at 17Khz.
 
 
 
I own the Stealth DC-1 and I am having a hard time convincing myself to upgrade to the Schiit Yggdrasil or the Auralic Vega. It does everything I need it to do, all the inputs/outputs I need, a well implemented volume control,  and sounds pretty damn good too. It is smoother sounding than my ESS Sabre Dac (EE Minimax Junior), but both of these units offer great value at their respective price points.
 
The DC-1 is just exceptional.

Sadly mine wasn't.  It sounded like garbage (worse than the XDA-2 I had before it) and I ended up selling it on eBay.  The buyer complained of additional problems and had to arrange for a replacement from Emotiva.  Not sure what happened after that.  

 

[KeithEmo]

   
 
So, in essence the TDA1387 is the typical junk-pile DAC chip for those not concerned with sharp rolloff at 17Khz.
 
 
 
I own the Stealth DC-1 and I am having a hard time convincing myself to upgrade to the Schiit Yggdrasil or the Auralic Vega. It does everything I need it to do, all the inputs/outputs I need, a well implemented volume control,  and sounds pretty damn good too. It is smoother sounding than my ESS Sabre Dac (EE Minimax Junior), but both of these units offer great value at their respective price points.
 
The DC-1 is just exceptional.

 
I'm glad you're enjoying your DC-1

 
 
I wouldn't be quite so harsh on the TDA1387 .... it's simply a good quality "basic DAC", which looks like it might lend itself very well to some types of DIY projects.
It just lacks many of the features that are available on most of the "better" audio DACs that are currently available.
 
For example, if you're listening to Red Book CDs, then the 16 bit precision isn't a limitation that matters.
And, while you will end up with a rolled off high end if you use it at 44k, some fans of NOS DACs seem not to mind that.
As another possibility, you could RIP your CDs (at 16/44), then oversample them to 192k using computer software, and play the output through your NOS DAC.
This would allow you to extend your high frequency response well above 20 kHz while still using a relatively simple analog reconstruction filter.
(There is at least one player program that offers several options for resampling in software - and recommends just such a DAC to go with it.)
And, if you're into programming and hardware, you could even create your own outboard hardware based oversampling filter to go before it.
 
However, that's much too long a list of shortcomings and limitations for the TDA1387 to be a commercially viable component today.
(When, for a few dollars more, I can get an alternative component that doesn't have those limitations and shortcomings.... which is why the TDA1387 has been replaced.)

 

[KeithEmo]

Have you guys seen the scope output on this page:
http://www.mother-of-tone.com/conversion.htm

 
It's very.... interesting.....
 
Unfortunately, it doesn't actually say very much. The author seems to think that Delta-Sigma DACs fail to accurately reproduce something he calls "timbre" - whatever exactly that is. He then goes on to show some pictures of what the signal looks like while it's on its way through a Delta-Sigma DAC (note that those pictures aren't of the analog output; they're of the signal partway through the process). It's sort of like asking you to compare two cars by showing you a partly assembled chassis sitting on the assembly line.
 
The simple reality is that the outputs of both R2R and Delta-Sigma DACs require filtering if you want to end up with the correct analog audio that's encoded in the signal. There's a very good reason why the author hasn't bothered to show pictures of what the actual analog output looks like - because you wouldn't be able to see the difference - because the differences are far smaller than anything you can see with the naked eye on an oscilloscope trace. The fact that the signals that exist partway through the process happen to superficially look "prettier" or "uglier" doesn't mean much - unless you're looking for pictures to hang on the wall.

 

[evillamer]

Well all this talk... Maybe it's time for Emovita to step up to the game and design a TOTL Sigma Delta DAC that sounds(& measures) better than ANY of the current top R2R Dacs (Metrum Acoustics Pavane, Schitt Yggdrasil, Totaldac D12, MSB Select/Platinum/Analog). And silience all Sigma Delta Critics once and for all?
 
e.g. Get to #1 position of Purrin's dac list, e.g. Exceeding Atomicbob's Yggdrasil Jitter measurements

 

[vhsownsbeta]

Well all this talk... Maybe it's time for Emovita to step up to the game and design a TOTL Sigma Delta DAC that sounds(& measures) better than ANY of the current top R2R Dacs (Metrum Acoustics Pavane, Schitt Yggdrasil, Totaldac D12, MSB Select/Platinum/Analog). And silience all Sigma Delta Critics once and for all?

e.g. Get to #1 position of Purrin's dac list, e.g. Exceeding Atomicbob's Yggdrasil Jitter measurements

LOL. I don't think Keith is trying to 'silence all Sigma Delta critics', he is merely offering an alternate viewpoint.

 

[evillamer]

 

Well all this talk... Maybe it's time for Emovita to step up to the game and design a TOTL Sigma Delta DAC that sounds(& measures) better than ANY of the current top R2R Dacs (Metrum Acoustics Pavane, Schitt Yggdrasil, Totaldac D12, MSB Select/Platinum/Analog). And silience all Sigma Delta Critics once and for all?

e.g. Get to #1 position of Purrin's dac list, e.g. Exceeding Atomicbob's Yggdrasil Jitter measurements

LOL. I don't think Keith is trying to 'silence all Sigma Delta critics', he is merely offering an alternate viewpoint.

Hey! Hey! hey! Don't diffuse my post. I was just trying to get a new DAC on the market.

 

[Sapientiam]

  Now what does this all have to do with 44.1 resolution and 8x oversampling?  'Cause you can get the response cut you need to avoid audible aliasing with a relatively gently sloped (less ringing) filter if you start the cut at 352.8 or 384KHz rather than 44.1 or 48KHz.  So that's why 8x oversampling became a standard so quickly: it allows use of filters that don't ring as much for a given amount of anti-aliasing effect.
 
Edit: Another way to say that last bit is that 8x oversampling allows filters that have both acceptably low aliasing and acceptably low ringing to be designed more simply and cheaply.

 
I'm already aware of what you've been explaining here so I'll cut to the chase which was my question to you regarding the claimed reason(s) 8X OS became the industry standard. If the designers involved in the chips (OS filter chips like NPC5813) which helped establish 8X OS as a kind of defacto standard - were following the principles you've just laid out, why did they introduce pre-ringing into those designs? All those oversampling filters from the mainstream manufacturers have it. There was no need to do this, since they used FIR filters the impulse response could be whatever they chose within the limit of tap number (which impacts on die area hence cost). To me this doesn't look like the rationale that 'ringing is bad for the sound, pre-ringing is the worst kind' was their guiding principle at all or they'd have moved all the ringing to after the impulse.
 
In my second paragraph I asked if you had any evidence to support the assertion that some people prefer unfiltered NOS due to the imaging distortion. I take it since you've been silent on that that you have none?

 

[Sonic Defender]

   
e.g. Get to #1 position of Purrin's dac list, e.g. Exceeding Atomicbob's Yggdrasil Jitter measurements

 
At what point is jitter audible? I seriously doubt any decent D-S has audible jitter. While I know as a technology it is questionable in a few key metrics, but forgive me for suggesting that I have also never before seen any study that demonstrates audible jitter in quality DACs of any stripe. I just can't accept the even if you can't hear the jitter it effects other things you hear without some kind of test that demonstrates this.

 

[purrin]

 
So, in essence the TDA1387 is the typical junk-pile DAC chip for those not concerned with sharp rolloff at 17Khz.

 
A lot of those vintage R2R chips, near the dawn of digital, belong in the junk pile. Personally, I'll take a solid D-S implementation instead.