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sound differences in DIGITAL cables - Page 2

post #16 of 108
yup, price doesnt always mean you get a better cable but then again, most of monster's stuff is pretty garbage
post #17 of 108
I'm surprised no one has mentioned it yet but of course there cannot be any difference between digital audio cables. A cable either passes the digital data or it doesn't, it is scientifically impossible for a digital cable to affect sound quality unless it's broken or too long, only the presence or absence of the digital data.

In fact I once witnessed an experiment which used a piece of household string as a digital interconnect. With some fiddling about, it passed digital audio bit perfect. You think even a cheap digital interconnect is going to pass digital audio any less efficiently than a piece of string?

The only possible way a cable can affect the quality of the sound is by introducing jitter. That's even if standard cables introduce more jitter than expensive ones, I've never seen any proof that they do! However, this is pretty much a non-issue these days as most decent DAC have jitter rejection circuitry which (effectively) completely removes all transport induced jitter. Retailers of expensive digital interconnects mention jitter every time, of course, they do not mention that it's a non-issue. If they did they did, who would buy it?

I know you are always looking for ways to improve your systems but please look elsewhere in your signal chain, digital cables do not and cannot make a difference!

BTW, someone mentioned that SPDIF on Coax should not be less that 1.5m, that statement is not true.

G
post #18 of 108
Quote:
Originally Posted by tot View Post
The good thing about optical cable is that there is no electrical connection between the devices, thus reducing changes for ground loops (humming).
its worth mentioning that in proper iec958 (spdif) you should have isolation pulse trafos on both sending and receiving side. so there's balanced ground-loop-free operation in coax, as well.

Quote:
Don't be. I don't believe you are hearing jitter. It is DAC's fault if incoming jitter affects the result, and modern re-clocking ones like Ultra Micro DAC should be immune to that.
I agree with this. its not a popular position to take, but I do take it.
post #19 of 108
Quote:
Originally Posted by gregorio View Post

In fact I once witnessed an experiment which used a piece of household string as a digital interconnect. With some fiddling about, it passed digital audio bit perfect. You think even a cheap digital interconnect is going to pass digital audio any less efficiently than a piece of string?
I simply MUST get my pasta interconnect working. just to prove a point

thin spaghetti almost works and linguini is harder to fit its eliptical cross-section into the toslink jack, but it can be done.

one of these days, I'm going to DO this experiment.

what I'm not sure about, is:

red sauce or white?

post #20 of 108
Quote:
Originally Posted by gregorio View Post
I
BTW, someone mentioned that SPDIF on Coax should not be less that 1.5m, that statement is not true.

G
its semi true, as I understand it.

they are worried about 'fast reflections' getting in the way of the bits due to short cable. short cable means reflections 'bounce back' faster, in time.

reflections overlap with real data.

what is often ignored is that the signal level of the reflections are low enough that any modern reclocker won't get 'disturbed' by reflections.

I bet you could measure the reflections. but that does not mean they AFFECT the integrity of the digital pulses in any meaningful way.
post #21 of 108
Quote:
Originally Posted by gregorio View Post
I'm surprised no one has mentioned it yet but of course there cannot be any difference between digital audio cables. A cable either passes the digital data or it doesn't, it is scientifically impossible for a digital cable to affect sound quality unless it's broken or too long, only the presence or absence of the digital data.

In fact I once witnessed an experiment which used a piece of household string as a digital interconnect. With some fiddling about, it passed digital audio bit perfect. You think even a cheap digital interconnect is going to pass digital audio any less efficiently than a piece of string?

The only possible way a cable can affect the quality of the sound is by introducing jitter. That's even if standard cables introduce more jitter than expensive ones, I've never seen any proof that they do! However, this is pretty much a non-issue these days as most decent DAC have jitter rejection circuitry which (effectively) completely removes all transport induced jitter. Retailers of expensive digital interconnects mention jitter every time, of course, they do not mention that it's a non-issue. If they did they did, who would buy it?

I know you are always looking for ways to improve your systems but please look elsewhere in your signal chain, digital cables do not and cannot make a difference!

BTW, someone mentioned that SPDIF on Coax should not be less that 1.5m, that statement is not true.

G
man you should give it a rest

how do you know it is bit perfect.
post #22 of 108
Quote:
Originally Posted by endless402 View Post

how do you know it is bit perfect.
take A, take another B, invert B and sum. you should get a steady (whole lotta, actually) zeroes.
post #23 of 108
I myself was surprised when I compared HGA silver with BJC coax for digital audio. HGA silver was brighter! should be the same since they are both passing 0's and 1's. But no! can't explain it - both are 75 ohms with respectable RCAs and solder connections.

so there it is! But I know it's not placebo....
post #24 of 108
Quote:
Originally Posted by glitch39 View Post
I myself was surprised when I compared HGA silver with BJC coax for digital audio. HGA silver was brighter! should be the same since they are both passing 0's and 1's. But no! can't explain it - both are 75 ohms with respectable RCAs and solder connections.

so there it is! But I know it's not placebo....
have you measured or quantified this?

placebos only fool humans. a scope is never bothered by pills, of any sort
post #25 of 108
Quote:
Originally Posted by gregorio View Post
A cable either passes the digital data or it doesn't, it is scientifically impossible for a digital cable to affect sound quality unless it's broken or too long, only the presence or absence of the digital data.
Correct, and also correct in that you state:

Quote:
The only possible way a cable can affect the quality of the sound is by introducing jitter. That's even if standard cables introduce more jitter than expensive ones, I've never seen any proof that they do!
This would explain why I've heard a difference with different connections and cables.

Quote:
However, this is pretty much a non-issue these days as most decent DAC have jitter rejection circuitry ...
I would say that most people on Head-fi are not using DACs that have any kind of deliberate jitter rejection circuitry, such that with them, you can hear a difference when using different cables.

Maybe the best thing to do would be to measure the levels of jitter in different cases yourself. Some people who have are Dan Lavry and Kingwa of Audio-gd. Each have posted their thoughts in various places on connections and jitter.
post #26 of 108
Quote:
Originally Posted by Currawong View Post
Maybe the best thing to do would be to measure the levels of jitter in different cases yourself. Some people who have are Dan Lavry and Kingwa of Audio-gd. Each have posted their thoughts in various places on connections and jitter.
what we need is how it *affects* the sound. the end-to-end effect.

even if you quantify the jitter, how does that affect the sound? compared to how other things affect it (the analog sections, not to mention the mixing and 'mistakes' done at mastering).

I really think its a mtn out of a molehill, these days. and most dacs do reclocking, at least that's my understanding from reading the spec sheets on various chips.

so what I'd be curious about is - if you can measure and identify the various grades of good and bad jitter cables - and then pipe their outputs to the various dacs and show what the dacs do and don't do about the various amounts of jitter.

has this work actually definitively been done? it seems against the industry's interests to actually expose how unimportant this jitter-in-the-cable stuff really is.

also, I've never heard anyone describe the 'sound' of jitter. why is that?
post #27 of 108
Quote:
Originally Posted by glitch39 View Post
I myself was surprised when I compared HGA silver with BJC coax for digital audio. HGA silver was brighter! should be the same since they are both passing 0's and 1's. But no! can't explain it - both are 75 ohms with respectable RCAs and solder connections.

so there it is! But I know it's not placebo....
Haha, so you can't explain it, but you can tell us with confidence it is not placebo? How come??
post #28 of 108
post #29 of 108
Quote:
Originally Posted by Currawong View Post
I would say that most people on Head-fi are not using DACs that have any kind of deliberate jitter rejection circuitry, such that with them, you can hear a difference when using different cables.
I have to strongly disagree.

if there is any audience that uses modern dacs, its THIS crowd and you know it!

thousand dollar dacs are almost the norm around here (or ones not shy of that price point).

I think only the very earliest (and I do mean *very* early) dacs truly sucked.

I do believe that people are looking to make more of this than this is to be had. boredom? who knows its a good problem to have - to not have any other real issues to chase around, but to blame digital cables for 'changing' the data and not giving the receiver-chip designers enough credit to be able to capture and separate clock from data.

I've been using digital audio for about 15 yrs now. I started doing DAT taping stuff (I was doing diy even back then) and even when we used really bad parts, we still got the spdif signal thru and things still seemed to work. even when we were fumbling our way thru, 15 yrs ago, when spdif was still pretty new.

today, I really don't see jitter as any real-world problem for the receiver chips and dacs. I think a lot of hand waving goes on, but not a lot of pointable conclusive evidence to show that its still a problem that *cable companies* need to care about. afterall, one of the design goals of digital audio was to stop need to *care* about cables. that's why they picked ubiquitous 75ohm video cables and even picked the 'wrong' connector (rca) for the connector of reference. and even with 'wrong' connectors, it still passed bits thru fine.
post #30 of 108
Quote:
Originally Posted by Nerull View Post
good paper, thanks for the link!

I noticed on p32 that they talk about using RAM and being able to run 2 pll's, sort of sounds like you have a 'long range tracker' and a short range one.

and the paper date was from the early 90s, when things *were* pretty young, still. ram was not cheap and having deep pipes in chips was not as common as today.

so, I do wonder, given how chips can be architected today, if a lot of that paper still applies. it talks about '100% dacs' and impulse dacs. those are 2 schemes but I bet there have been a dozen since that paper's date (?)
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