lmao, now I know you are completely 100% fooled by your own subjectivity.
Different Quality Digital cables alter SQ? Hehe. The DAC is everything to the Digital Cable....if the sound is altered then its the DACs fault since the digital cable simple sends bits...um that would be 1s and 0s. No way a cable alters 1s and 0s.....😱
Its been over 6 months since I started reading this thread and I think its been posted several times but I will ask again.
Why haven't you done the complete and fully controlled tests to just backup your opinion?
DAC design is very specific, and out of reach of almost all amateurs. It's very easy to create jitter via non-optimum supply wiring for instance. Which amateur has the knowledge and intrumentation to verify this?
[snip]
... or not designed at all. 😉
jd
Hi Janneman,
Julian Dunn (who died unfortunately in 2003) first explored some of the jitter problems, most of his papers are in the AES library, but some can be found at his website:
Nanophon - Digital Audio Papers
AFAIR in the Hawksford/Dunn paper, at least some measurements (and simulations) were done, not only at the DAC clock but at the analog outputs as well.
Anyway it is of course common sense that clean clocks not influenced by the incoming data or connection to other components will lead to clean outputs not suffering from jitter effects.
But the important part of this story is, that the usual argumentation back then, why jitter at the interface couldn´t lead to audible was dead wrong, simply because it overlooked a certain aspect of clock recovery circuits.
I don´t know if that must be called ´incompetent´as it is quite seldom that human beeings are able to contruct and build _perfect_ gear. More often something is overlooked and the products have to evolve over some time as several mechanism were better understood with more research.
As it was the case with AES-EBU (S/P-DIF). BTW, the TOS-Interface quite often produced a whole lot more jitter than the coax version- remember that a lot of listeners in those days noticed that the TOS connection sound worse?
Wishes
Julian Dunn (who died unfortunately in 2003) first explored some of the jitter problems, most of his papers are in the AES library, but some can be found at his website:
Nanophon - Digital Audio Papers
AFAIR in the Hawksford/Dunn paper, at least some measurements (and simulations) were done, not only at the DAC clock but at the analog outputs as well.
Anyway it is of course common sense that clean clocks not influenced by the incoming data or connection to other components will lead to clean outputs not suffering from jitter effects.
But the important part of this story is, that the usual argumentation back then, why jitter at the interface couldn´t lead to audible was dead wrong, simply because it overlooked a certain aspect of clock recovery circuits.
I don´t know if that must be called ´incompetent´as it is quite seldom that human beeings are able to contruct and build _perfect_ gear. More often something is overlooked and the products have to evolve over some time as several mechanism were better understood with more research.
As it was the case with AES-EBU (S/P-DIF). BTW, the TOS-Interface quite often produced a whole lot more jitter than the coax version- remember that a lot of listeners in those days noticed that the TOS connection sound worse?
Wishes
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Yes, I agree but the fact is that many, if not most equipment on the market then doesn't have good DAC's, in which case cables can influence SQ. It doesn't help to make statements of how things should be done while in reality it is done different most of the time.
That's a nice procedure
So:
- you use a crappy DAC, then swap digital cables, hear differences and decide "this cable is better/worse".
Which is equivalent to:
- you use a crappy power amp *, then swap speaker cables, hear differences and decide "this cable is better/worse".
* E.g. known as unstable in capacitive loads, or low damping, etc...
I think it is important to know this. If you aware of these issues you may decide to spend, for instance, $ 1500 for a Benchmark Media DAC or $ 2500 for an Ayre DAC or any of a lot of competently designed DACs which are immune to jitter on the digital signal, instead of blindly spending the same or more on cables in the hope that the two errors cancel 😉
jd
Yes that's how it often goes, but if at this point in time your DAC changes sound with the digital cable, that DAC is not a Good DAC...
jd
@ syn08,
most designers of gear at that time wouldn´t have noticed that they had designed `crap´ if not people just had listened and complained about the sound quality.
Today that shouldn´t happen anymore, but what if you like the sound of your dac and it unfortunately isn´t perfect in respect to jitter?
Wishes
most designers of gear at that time wouldn´t have noticed that they had designed `crap´ if not people just had listened and complained about the sound quality.
Today that shouldn´t happen anymore, but what if you like the sound of your dac and it unfortunately isn´t perfect in respect to jitter?
Wishes
Uh... yeah. Better or worse for that particular connection. And it certainly does not come down to more expensive or fancier. It's probably just a better impedance match.
If all digital sources and DACs used nice BNC connectors, we might never have this problem. A good Belden or Canare cable would do the trick.
That's one reason I like the ESS Sabre DACs. They don't even try to recover the embedded clock. They pull the signal apart and put it back together reclocked. Jitter be gone. =) A good spdif receiver chip can do almost as well.
I don't think you can say better or worse. Very often it boils down to what you like, and if you would measure it you may find that you actually prefer the one with the worse performance. That's what often happens in audio, with cables, amps, what have you. You can't say, I go to live performances, so I can select the 'best' performance. The technical errors of equipment have no equivalent in the (live) music itself, so your only reference is what you like or not like.
Edit: you may also find that the cables that sound 'different' in those cases are often cables that have extreme technical parameters, like high cap combined with low L or low cap but high resistance, whatever. Because the cable will be selected more if there is a clear difference, they *have* to be made extreme...
jd
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That´s of course true, but see my response to syn08. It sometimes doesn´t help to know that your DAC isn´t perfect. 🙂
But the story has another point; afair there never was a dbt on interface flaws before, but Julian Dunn nevertheless decided to investigate the interface problem, just because a lot of people were complaining after listening.
A good example of a professional open mind approach i´d think.
And i often find it a bit surprising that sometimes the same people who said at the beginning of a study that any audibility is _impossible_ are those, who said at the end, that any gear suffering from this problem must be crap. 🙂
(No i don´t mean you, nor syn08)
Wishes
And all those that "just had listened and complained about the sound quality" were using "good" digital cables in the decision process?
One point about design flaws is that often time IC manufacturers fail to specify parameters that end up having ramifications on design. Some times these parameters may change due to process shifts.
(1) Unspecified parameters are difficult to design to and get the design right.
(2) If an unspecified parameter shifts, by definition the part is still "good" even though it may negativly impacts the end product.
(1) Unspecified parameters are difficult to design to and get the design right.
(2) If an unspecified parameter shifts, by definition the part is still "good" even though it may negativly impacts the end product.
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Hey, for the evaluation of ´crap´ even bad cables were good enough; for todays fine equipment surely the best is needed. 🙂
Apart from that.....nice one! 😀
Wishes
Apart from that.....nice one! 😀
Wishes
Group A claims an audible difference from a change in some parameter, Group B sees no possible mechanism and claims it's fictitious. Group B draws conclusions about the motivations and perceptual competency of Group A as a result.
Further investigation reveals a mechanism by which Group A's claim has potential validity. A flaw is recognized and rectified. Group B now takes possession of that flaw and the attendant knowledge to rectify it, in a sense hijacking it from group A. "Of course jitter is a factor, everyone knows that". Insert jitter, IMD, auditory masking curves, etc.
But having convinced themselves Group A is deluded, Group B's assessment of Group A doesn't change because Group A still believes in things without explanation. Go to Step 1 above.
You would be surprised how easy it is to really mess up reclocking. I'm not saying the ESS isn't good, I don't know it so I have no opinion on that.
But complacency is a sure road to Bad DACs 😉
jd
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