Thoughts on a bunch of DACs (and why delta-sigma kinda sucks, just to get you to think about stuff)
Jun 25, 2015 at 4:32 PM Post #6,031 of 6,500
   
 
You can use that same or similar software to "sharpen" a picture of something else, such as a human face, or a license plate number. You can even base some of your assumptions on the way in which pictures tend to get blurred when a camera isn't perfectly focused. This will give you a "pretty good guess" that sometimes produces remarkably good results. However, it also sometimes produces bad results, because your assumptions aren't always true. (Modern software can even be written such that, assuming you are hoping to make a license plate number readable, the software can "detect how well it worked", and even adjust its operating parameters accordingly. This would allow it to try different settings, and finally use the one that produced a result that was closer to what it expected or "hoped for". However, in reality, it's still a guess.) To take the extreme example, if I was the photographer, and I DELIBERATELY shifted the picture out of focus, then your assumption that it should be sharp is wrong, and, even if you could do so perfectly, making it sharp will "destroy" it.
 
Personally, I would leave anything that deliberately alters the signal in the "mastering process". (If I was remastering a CD, and I happened to know that it was converted with a specific brand of A/D converter, and also had a way to correct the specific errors introduced by that encoder, then I would so so.... although, even then, if my correction process generates other new errors, I have to decide whether my new version is really "better" or not.)
 
(This question comes up frequently in legal cases. If I start with a fuzzy blob that's supposed to be the bad guy's face on a security video, with enough signal processing I can probably "sharpen" it to the point where it looks like a human face. However, can I trust it to look like the right face? Or did my software do such a great job that it essentially created a face from insufficient information, in which case who it happens to look like is almost purely random? Or, even worse, does it offer so many options that, if I keep trying different settings, I can produce a result that looks like whomever I want it to - at which point I cheerfully declare "that's the guy" and stop trying new options?)

 
There has been quite alot of technology that tries to "restore" audio. Example will be BBE Sonic Max or Creative Xfi Crystalizer or Pioneer Sound Retriever to name a few.
 
http://www.tomsguide.com/us/creative,review-490-3.html
 

 

 
These audio processing software alter the transients quite abit. If done incorrectly or with certain music types, will likely exceed the volume headroom and distort.
 
Jun 25, 2015 at 4:45 PM Post #6,032 of 6,500
 
If you have $10k invested and cant hear the difference between gear, thats a personal problem. I cant imagine what would satisfy you in this argument other than coming to our houses and watching us pass an abx test. Why dont you stop worrying so much, sell your gear, and maybe take some cooking classes or somethint.

 
There are at least a few people in this world who are "pitch perfect"; these souls can tune a piano by ear, and would almost certainly notice if a CD (or a record) were playing 0.1% fast. However, I'm not one of them, and I'm pretty sure I wouldn't notice such a speed error at all. However, it's still true that a record or CD should play at the correct speed, and that failing to do so is an error. Therefore, I can't make claims like "it doesn't matter" or "it's inaudible". (I can reasonably say that I can't hear it, or that xx% of the population can't hear it, or, if I was in the marketing department of the product being discussed, I could even say "not enough of our customers can hear it that it's worth us fixing it", but none of that even suggests that it doesn't exist, or that it it "totally inaudible".)
 
And we can leave the argument about whether I'm lucky - because I could buy a cheap piano and never notice the difference; or whether I'm deprived - because I'll never be able to experience the true joy of a perfectly tuned piano; for philosophy debates.

 
Seems like Absolute pitch is a god given/natural born talent/perk(fallout 4 anyone?).
 Researchers estimate the occurrence of AP to be 1 in 10,000 people.

 
https://en.wikipedia.org/wiki/Absolute_pitch 
 
It seems that you can be trained to be relative pitch
 
https://en.wikipedia.org/wiki/Relative_pitch
 
Jun 25, 2015 at 5:06 PM Post #6,033 of 6,500
   
I would much prefer to pair a Sabre DAC with somewhat laid back headphones whose sound character complements it - like planars.)
 
 
 
 
 

I certainly subscribe to your way of thinking, but I'm not sure the new planar offerings from HiFi Man for instance would be a slam-dunk compliment as the 560 and now 1000 are very well extended with plenty of high frequency energy. Still, I get what you mean and agree. I wouldn't get a detailed implementation of a Sabre chip and use it to listen to poorly mastered rock with a Grado SR325. No sir. Now throw in an HE 500 or Oppo headphone ... different story.
 
Jun 25, 2015 at 5:34 PM Post #6,034 of 6,500
I certainly subscribe to your way of thinking, but I'm not sure the new planar offerings from HiFi Man for instance would be a slam-dunk compliment as the 560 and now 1000 are very well extended with plenty of high frequency energy. Still, I get what you mean and agree. I wouldn't get a detailed implementation of a Sabre chip and use it to listen to poorly mastered rock with a Grado SR325. No sir. Now throw in an HE 500 or Oppo headphone ... different story.


Oppo, older hfman, any audeze, senn 6x0 and prolly many others that I never tried .. and an even bigger selection of dark/smooth speakers. Or just use pretty much any tube amp or most of the small portable amps ... or (the horror), use an EQ :)
 
Jun 25, 2015 at 5:53 PM Post #6,035 of 6,500
"perfect pitch" isn't necessarily a great thing to have - pitch standards have changed over the centuries, there are still a few concert pianists that like the last previous standard lower pitch - the whole orchestra has to tune to their piano
https://en.wikipedia.org/wiki/Concert_pitch
 
relative pitch is what most everyone uses, gives the sensations of consonance/dissonance with chords, temperaments
 
even the uncorrected Sana Clip+ is fine to listen by itself with its software 0.25% pitch error
 
Jun 25, 2015 at 7:11 PM Post #6,036 of 6,500
Can anyone explain why hi hats sound different on sigma delta vs r2r (ch ch ch vs tsh tsh tsh)

Is it because of accumulator overload or non-filterable aliasing or lack bits in modulators(quantization errors) or feedback issues?

 
Its not really an explanation but the cause seems to be noise floor modulation - in other words signal-dependent changes in the background noise. Its not the first two of your suggestions, could be a combination of the last two. Quantisation needs to be correctly dithered to avoid modulation noise - that means a certain amplitude and probability density function noise source needs to be added in prior to word length reductions. From my (fairly limited) knowledge this precise dither source isn't used at the quantizer in S-D converters. If anyone has links to show me I'm wrong here and that it is, I'll be glad to follow them up.
 
Jun 25, 2015 at 7:15 PM Post #6,037 of 6,500
Can anyone explain why hi hats sound different on sigma delta vs r2r (ch ch ch vs tsh tsh tsh)

Is it because of accumulator overload or non-filterable aliasing or lack bits in modulators(quantization errors) or feedback issues?

Here's a quote from Børge Strand-Bergesen which I think sums it up nicely:
 
SABRE ISSUES
An intriguing side issue was brought up by Strand-Bergesen when he was explaining why he chose the AKM DAC chip to sit inside his chassis. One of the DACs under consideration was the current DAC flavour of the month, the ESS Sabre. Unlike many manufacturers out there, though, Strand-Bergesen rejected the Sabre out of hand, he believes that the design of this DAC is fundamentally flawed, “It’s riddled with maths trouble. The digital maths is disappointing. It will overflow internal registers, chopping up and generating a lot of output edges. It sounds distorted around the treble area. With a high power amp, it could kill the treble. I have a friend of mine who has access to the in-house data sheets of the Sabre. He actually has a work-around for it. Well, for the 9012 and 9018 chip models. Although on the 9022 and 9023, you cannot initiate the work-around because there are no pins to access the internal registers and bypass this problem.”
 
Jun 25, 2015 at 7:25 PM Post #6,039 of 6,500
  He believes - that statement doesn't give anything much of evidence on which he's based his belief. For example, when does the overflow of the internal registers occur? Looks to me too much like FUD.


I don't know, sounds pretty convincing to me.  As far as "when does the overflow of the internal registers occur?", why don't you ask him?  Maybe he can explain it in glorious detail. 
beyersmile.png

 
Jun 25, 2015 at 7:26 PM Post #6,040 of 6,500
If that guy is correct then it seems like a slam dunk conclusion and correlates to the ears of many who have heard a bright/neutral headphone with the average $250-$1000 Sabre. That isn't always a great pairing, but take the darker sound of the LCD-2.2 and you have a good combination for many. 
 
Also moving back to the people who were talking about the DT880/HD800 with their treble peak. Taking the DT880 and pairing it with the R-2R Theta does not remove the treble peak or make it much more resolving. The Theta has a noticeably more circular soundstage and image versus the AKM Bifrost Uber and treble that is natural. I think the tonality of the Bifrost Uber is pretty spot on, but the overall image/soundstage/phase correction is influenced more by the burrito-filter DSP chip.
 
Oh yeah and of course in the dynamics/transients/bass/slam department the Theta walks all over the Uber
 
Jun 25, 2015 at 7:30 PM Post #6,041 of 6,500
   As far as "when does the overflow of the internal registers occur?", why don't you ask him?  Maybe he can explain it in glorious detail. 
beyersmile.png

 
Maybe he could but since I have other reasons (unrelated to his claims) for not using Sabre DACs, I can't see how it would benefit either of us for me to ask. I put the question not because I'm curious to know the answer (I've looked at too many plots of THD+N for Sabre to know it can't be happening on normal sinewaves) rather to show how his statement could be made more persuasive.
 
Jun 25, 2015 at 7:34 PM Post #6,042 of 6,500
As you know in any type of digit based conversion, currency or floating point to integer, there's always chance for rounding errors.
 
In the Sigma Delta world, when the PCM 16bit 44Khz data is converted into 5bit 1MHz Bitstream(for example), won't it introduce some form of rounding errors as well? Especially if we don't know if they use double precision or single precision or etc. Also during the process of conversion, won't any kind of electrical interferences and jitter affect the precision?
 
Jun 25, 2015 at 7:38 PM Post #6,043 of 6,500
Converting from 16bits down to 5bits certainly generates lots of rounding errors - called 'quantisation noise'. Its the job of the S-D modulator to make those errors inaudible - by forcing them up to higher frequencies (above 20kHz). Single or double precision applies only to floats, but here its fixed point.
 
If electrical interference or jitter affects the result of a truncation, the design's broken. Digital is able to ignore noise completely below a certain level.
 
Jun 25, 2015 at 7:55 PM Post #6,044 of 6,500
The only thing about ESS is the lack of detailed datasheets(not including those NDA ones) like those you find on TI or AD or even AKM dacs. Especially things like Monotonicity, PSSR, Digital Filter Graphs etc.
 
Jun 25, 2015 at 8:02 PM Post #6,045 of 6,500
  Converting from 16bits down to 5bits certainly generates lots of rounding errors - called 'quantisation noise'. Its the job of the S-D modulator to make those errors inaudible - by forcing them up to higher frequencies (above 20kHz). Single or double precision applies only to floats, but here its fixed point.

 
Nothing's wrong with this carpet or room, it's very clean and nice. 
wink_face.gif

 

 

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