Digital coax vs. Optical

I have been confused on this issue until today. Some say digital coax some say opitcal for sound. Eddie has stated that you must have an opital cable for best audio. I have been told that the digital coax and opitcal cables both do the same task and not one is better than the other...signal is just transmitted differently..I got two opinions on this. One was by tech support at Best Buy the other from a tech at Crutchfeild both said exactly the same thing not one is better than the other.. To coax vs. optical...The ONLY way the optical cable could be a better source is if you have to run 25 feet or more from one source to the other. Then the optical light would in essence transmit quicker. I doubt any of us would even notice the difference especially if your receiver has auto or manual "lip-sync" capabilites while watching a movie...music only; no difference at all. Please give me your opinions on this subject and what you ahve experienced. Thank you

I find that the optical has more of a tinny sound
base seems better with digital cable

I have never owned the optical cable always had the coax..I have heard through out the years differing opinions on this and when I have asked a "pro" they say there is no difference but the way it is transmitted. So why both options then? The only reasonable one that I have is for game consoles. Alot of them do not have the coax just the optical connection for dolby surround.

If optical is the default, you can be sure that it's cheaper to implement. Back in the day, the high end sided with coaxial, but even then, the differences weren't terribly evident at the mainstream level. It's really a non-issue unless really long runs or ultra-resolution comes into play. Then testing of the various options may be in order. Personally, I feel more comfortable with coaxial. I've bent and trampled a few optical cords in my day.

Length of cable isn't an issue in homes usually, unless you have some absurd 50 ft runs or something.
Technically, there shouldn't be any difference between coax and optical.
The reason why coax is said to be better is simple. With optical cables, the data is converted one additional step. From electrical modulation to light modulation and back. This extra conversion step doesn't occur with coax.
No matters though. These chips don't make a mistake. It's a 1 or a 0, always. So there should be no advantage to either.

Coax used to be more durable, I think manufacturers have optical cables down pat now though.

..is in a high EMI/RFI environment and electrical noise is a problem or there
s a ground loop fbetween the source/destination.. Other than that there's no difference in performance but coax is more flexible, has much more forgiving connectors, and virtually ANYcheapo interconnect will work fine.

Trust me, that light/time thing is pure BS.

a friend of mine and i tested two cable of about the same value and we could discover no real difference in performance.The big thing was the cable ends,the coax have a much tighter seal than the optical.I do think however as you get into expensive cables,coax performance will go up,while optical will improve if you use glass plugs instead of plastic.
thanks
bill

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Originally Posted by musicman1999

I do think however as you get into expensive cables,coax performance will go up,while optical will improve if you use glass plugs instead of plastic.

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if the 1's and 0's make it through the cable and to the error correction, it's all the same.

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Originally Posted by kexodusc

These chips don't make a mistake. It's a 1 or a 0, always. So there should be no advantage to either.
though.

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Optical "sounds" cooler though. If you tell your friends that you have optical cables in your stereo set-up, they say, "that's cool dude. You must have a great system!" If you tell them you have coax, they don't blink an eye.

Now there's something you can base a decission on.

For those of you who don't know me, this has been a joke. Please smile. ;)

I have and older Zenith and Pioneer dvd player that has opt and coax output. My opt. wire was from GE. The coax wire was some unnamed source. I had both wires connected into the Sherwood 6095R that I use. I hit the input switch switching back and forth between the two connections trying one player at a time. Both sounded good, but both did not sound the same. I felt the coaxial gave tighter control over the audio much like a higher damping factor in an amplifier. Lets say you were looking at the mark of a fine and medium ball point pen. The coax was more "fine", the opt. more "med". I liked the coax for movies and the opt. for music(the opt. had a more "tube like sound).

I know we talk alot about one's and zero's here. Recently my brother put an older Pioneer Dv-525 player on his system and then put back his Pioneer Elite Dv38. The output tested was the coaxial. Both players deliver the one and zeros but that elite player is putting out some kind of better one and zeros then the 525. There is a hell of a difference of sound between these two machines. I have long ascertained that the one and zero thing has a SIGNATURE. We can all write the same words and numbers on a piece of paper, but due to our differences in handwriting they will look similar but not the same.

Forgive the rest of these people, they do not understand. They claim that if you connect a $50 DVD player by optic cable to say a $1500 receiver the sound of a CD will be exactly the same as if you connected a $500 DVD player by optic cable to a receiver. They also claim that a $10 optic cable will sound the same as a $100 optic cable. In regards to the former, you & I obviously have experienced the differences in sound but other people who for the most part haven't actually done a real life comparison, but yet are all to willing to dismiss someone elses comments , out of ignorance. To quote Mr. T, I pity the fool.:16: :17:

ed

you are saying two different things.That different dvd players will sound different and that different cables will sound the same.Different dvd players may have slight differences in sound due to better quality internal components reading and transmitting those 1's and 0's.If you listen to a $29 dvd player and a $2500 player may sound a little better,but even then it may be hard for the average person to detect.But then you also say different cables sound different,but the cable comes in after those 1's and 0's have been read and sent to the output stage.In the analog world cables make a difference,digital world no.
bill

Ed-

I appreciate your posts, really. But this topic is making me mental. It's 1's and 0's. The grey area in between exists only between your ears. There's nothing wrong with that, every one is entitled to have opinions that are not grounded in reality. But to not recognize them as such is ignorance.

It's 1's and 0's, OK, but isn't there also the matter of jitter?

I had the impression from people who've tested such things that coaxial typically results in slightly less jitter, but the difference is not audible.

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Originally Posted by EdwardGein

Forgive the rest of these people, they do not understand. They claim that if you connect a $50 DVD player by optic cable to say a $1500 receiver the sound of a CD will be exactly the same as if you connected a $500 DVD player by optic cable to a receiver. They also claim that a $10 optic cable will sound the same as a $100 optic cable. In regards to the former, you & I obviously have experienced the differences in sound but other people who for the most part haven't actually done a real life comparison, but yet are all to willing to dismiss someone elses comments , out of ignorance. To quote Mr. T, I pity the fool.:16: :17:

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Dont forget when running through the optic, the receiver is doing the bass management and the Dac's. Really, but for just reading the signal and sending it,thats all the player at any cost is doing.

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Originally Posted by musicman1999

ed

you are saying two different things.That different dvd players will sound different and that different cables will sound the same.Different dvd players may have slight differences in sound due to better quality internal components reading and transmitting those 1's and 0's.If you listen to a $29 dvd player and a $2500 player may sound a little better,but even then it may be hard for the average person to detect.But then you also say different cables sound different,but the cable comes in after those 1's and 0's have been read and sent to the output stage.In the analog world cables make a difference,digital world no.
bill

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The difference in the digital audio quality out of my brother's Marantz 5400 receiver of the Pioneer DV-38 and the DV-525 players was far more than slight, more like quite significant on his system. Years ago, like back in the late 70s, he had a rather powerful stereo system with large floorstanding speakers. I tested two phono cartridges, the Shure M91ED and the V15 type 111. On that system, the M91ED sounded like mud in comparison to that V15 111. On the same token, I was using a Fisher 35 watt tube amp on two Marantz IMP 6Gs. I performed the same test and found there was not too much difference in audio quality between the two cartridges on that system.

Yes, jitter or timing problems are theoretically possible with optical cables, and it is possible to design optical cables with an eye toward minimizing jitter--that is, the possible scattering of light that could make the reading of those digits slightly less reliable and steady. It's also possible to vary materials in optical cables to ensure signal stability over long runs. But loss of a digital signal is unmistakeable; sound disappears or drops out. It isn't a delicate sound-quality issue. Although, theoretically (at least according to some wags), the smearing that jitter can cause may be audible, the vast majority of people--experts and amateurs alike--maintain that such differences are either very hard to hear or absent altogether. To claim that an obvious difference in sound quality between different optical cables is routinely evident flies in the face of both science and universal experience. If someone is capable of discerning sonic variations in optical cable, I can't imagine why he would ever have to ask other people endless questions about whether sound quality really varies in far more obvious contexts.

ED, some time ago, my brother's audiophile friend had bought a DAC for his CD player that featured a opitcal output. One day he came over and stated that he had been getting rather lousy sound so he sold the DAC and bought another one that used a coax cable instead. He was pleased with the result. He also gave my brother the optical cable which was from AR. It sat around for a year or two in our home. When I got my first D.D. receiver I had bought a GE opt. cable. I tried both cables on my Zenith player. The AR was dull as can be in audio quality. The GE on the other hand was fine. The way I see it was that for some reason the AR cable's signature or function was not up to snuff. If I were a technichan with equipment to analyze this stuff, I would be experimenting right now. I can tell you one thing; I am not about to play Consumers Union and spend a bunch of monies on different optical cables too see how much of a difference there is among brands and their costs.

Edtyct; If what you say is true, then why did the AR cable I describe sound so flat and failed to produce much high frequency detail?

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Originally Posted by kelsci

The difference in the digital audio quality out of my brother's Marantz 5400 receiver of the Pioneer DV-38 and the DV-525 players was far more than slight, more like quite significant on his system. Years ago, like back in the late 70s, he had a rather powerful stereo system with large floorstanding speakers. I tested two phono cartridges, the Shure M91ED and the V15 type 111. On that system, the M91ED sounded like mud in comparison to that V15 111. On the same token, I was using a Fisher 35 watt tube amp on two Marantz IMP 6Gs. I performed the same test and found there was not too much difference in audio quality between the two cartridges on that system.

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Understand, phono cartridges are transducers which are euphonic by design. IOW, they are made to sound different. And, comparing different speakers/amp combinations to a digital feed is likewise foolish.

Neither of these are valid comparisons to a digital signal where ones are ones and zeros are zeros, and never the twains shall meet.

If I may, I'd like to quote Doyle from Sling Blade:

"If you all don't shutup, I'm gonna go out of my mind!"

As Mark said, it's 1's and 0's people. Digital is a totally different animal than analog. With digital it's either on or off. Is there light coming out of your optical cable? Yes? Good. The cable passes. It works. Here's an idea..look down the end of an optical cable and see which light looks better. That will tell you which cable will sound better. The cleaner the light, the cleaner the sound..right?

So good, I have to post it again:

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Originally Posted by N. Abstentia

Here's an idea..look down the end of an optical cable and see which light looks better. That will tell you which cable will sound better. The cleaner the light, the cleaner the sound..right?

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Originally Posted by kelsci

Edtyct; If what you say is true, then why did the AR cable I describe sound so flat and failed to produce much high frequency detail?

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kelsci,

My casual answer would be jitter, or some flaw in the transmission in the light pulses--in other words, the information getting to the right destination but not before the light stream scattered, causing the high frequencies to smudge. Just a guess. The point is that the difference was not due to a discrepancy in how the cables sent the data but to serious timing interruptions in the AR. The AR certainly wasn't trying to achieve a "dull" signature sound. Other than that, I'm at a loss. I've used a multitude of toslink and coaxial digital connectors over the last two decades. I prefer coaxial for certain practical reasons, but I can't say that I've heard any glaring differences between digital cables during that time. I should say, as well, that I'm not a skeptic about cables in the analog domain, having heard major distinctions through the years. Nor am I so wedded to current scientific doctrine that I can't imagine something completely unforeseen changing the terrain. History is littered with supposedly incontrovertible scientific dogma that some brilliant little observation overturned forever (think of the transition from Newtonian physics to relativity and quantum mechanics, for instance; Newton's version had oodles of empirical evidence to back it up before other empirical evidence supervened). But variations between optical cables has never caused me a moment's notice. If someone else hears them when I, and presumably others don't, so be it. Discussion over, as far as I'm concerned, unless we're all prepared to rewrite the new laws of physics--to which I'm not opposed at all.

Ed

>My casual answer would be jitter, or some flaw in the transmission in the light pulses--in other words, the information getting to the right destination but not before the light stream scattered, causing the high frequencies to smudge. Just a guess. The point is that the difference was not due to a discrepancy in how the cables sent the data but to serious timing interruptions in the AR. The AR certainly wasn't trying to achieve a "dull" signature sound. Other than that, I'm at a loss. I've used a multitude of toslink and coaxial digital connectors over the last two decades. I prefer coaxial for certain practical reasons, but I can't say that I've heard any glaring differences between digital cables during that time. I should say, as well, that I'm not a skeptic about cables in the analog domain, having heard major distinctions through the years. Nor am I so wedded to current scientific doctrine that I can't imagine something completely unforeseen changing the terrain. History is littered with supposedly incontrovertible scientific dogma that some brilliant little observation overturned forever (think of the transition from Newtonian physics to relativity and quantum mechanics, for instance; Newton's version had oodles of empirical evidence to back it up before other empirical evidence supervened). But variations between optical cables has never caused me a moment's notice. If someone else hears them when I, and presumably others don't, so be it. Discussion over, as far as I'm concerned, unless we're all prepared to rewrite the new laws of physics--to which I'm not opposed at all.<

Whether I think your post is sensible because I agree with it or I agree with it because I think it's sensible is irrelevant! :)

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Originally Posted by kelsci

Edtyct; If what you say is true, then why did the AR cable I describe sound so flat and failed to produce much high frequency detail?

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Maybe you didn't plug it in all the way? Maybe some dust got in front of the lens? Bent it too much? Jacket is nicked? Recevier configuration problem...maybe you were actually hearing the analog signal?

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Originally Posted by N. Abstentia

If I may, I'd like to quote Doyle from Sling Blade:

"If you all don't shutup, I'm gonna go out of my mind!"

As Mark said, it's 1's and 0's people. Digital is a totally different animal than analog. With digital it's either on or off. Is there light coming out of your optical cable? Yes? Good. The cable passes. It works. Here's an idea..look down the end of an optical cable and see which light looks better. That will tell you which cable will sound better. The cleaner the light, the cleaner the sound..right?

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I'm a lawyer (not an electrical engineer), but IMHO -- I don't think it's that simple.

Here's a good thread on the topic, with some good links too:

http://forums.slimdevices.com/showth...jitter+optical

Why jitter isn't a problem:

http://en.wikipedia.org/wiki/Jitter_buffer

If any bits were to be switched despite having a buffer, the information would probably become meaningless to whatever is reading it and cause the audio to stop completely.

It's digital...as in digits. It's 1's and 0's. The DAC has a buffer to correct timing/jitter. 1's and 0's that encode audible high frequencies are not any different than the 1's and 0's encoding they low frequencies. An optical cable will not pass or dampen any specific frequency. You would have to send a lot of bad bit's down the cable to make an obvious audible defect. That kind of error rate just doesn't happen, and DAC's are designed to mask these errors anyway. A perfect digital signal is a square wave form. You can add a lot of noise and interference and signal degredation to the wave form and still accurately extract perfect 1's and 0's from it, a lot. Transfer of digital signals down optical cables is very very very accurate. If you've ever downloaded a an OS software update you've downloaded as many bits as encode a typical song on a CD. Those bits are transferred over miles and miles of optical cable and copper cable and maybe through the air, through zillions of switches and they arrive perfect. The whole modern world depends on the ability to transmit 1's and 0's flawlessly at much higher rates and greater accuracy than is required to perfectly recreate audio. One requirement of audio is that the bits need to be sorted out in a continuous stream with respect to time. The DAC does this, they have buffers and clocks. Better DACs (with better internal reclocking) do it better, but I'll wager it takes a very rare individual and system to hear it (the reclocking/jitter correction difference, I mean). Your transport also has error correction. Transports do this well too. If they didn't software would never install...


rant...rant...

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Originally Posted by noddin0ff

Those bits are transferred over miles and miles of optical cable and copper cable and maybe through the air, through zillions of switches and they arrive perfect.

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Very good point.

With all due respect (and I mean it), these devices are not perfect, although tolerance for a certain amount of jitter is the rule of the day. As teledynepost says, major interruptions in a digital stream would cause audio to drop out altogether, but reflections in cables measured in nanoseconds (often at the termination point, apparently, for toslink) can cause enough jitter to affect a DAC's performance. I completely agree, however, that unless something is seriously amiss, jitter error is inaudible, at least to me and to most other people. However, mainstream transports and DACs do not eliminate jitter entirely. Jitter seems to have been more of a problem for Toslink in its infancy, but so it was in all aspects of digital sound reproduction. Coaxial cables weren't immune from jitter either. But holding impedance steady along the entire transmission line can keep it well in check.

In the 1980s, the electronics industry subjected us to the idea that CD had delivered "perfect sound forever." After all, zeros were zeros, and ones were ones. But we've become much more aware of the variables since then, despite how cut and dried digital events seem to be in the abstract. The transmission of relatively noncritical computer data proceeds with very few problems. But higher-level audio is a much more delicate affair. Although the days of brickwall DACs are long gone, jitter is an ongoing issue for those who measure and/or have high standards, and the learning curve for digital audio has far from ended.

I just don't see how jitter could even be a consideration in a 3' optical cable. 500 feet? Maybe, but still very doubtful if the cable is properly installed and terminated. But 3 feet? I don't think so.

I agree with a lot of what you say. Jitter does exist, and nothing is perfect. But, as you say the error is inaudible to most. And by most I would estimate that the odds of someone actually having the right gear, the right environment and the right ears to notice it are very slim (especially given that no one has even put forth a reasonable description of what jitter should sound like).

But to bring things back into perspective. Is there any reason to believe that one digital cable sounds different from another digital cable in normal home consumer usage? Absolutely not. Cables don't introduce audible jitter.

N. Ab and noddinOff,

Just to set the record straight, I agree with you. I was simply discussing jitter as part of the terrain, an interesting and subtle part of it that can affect sound--most noticeably, if at all--when a cable has serious flaws or when it is asked to do something for which it wasn't designed. I don't for a moment think that properly functioning cables, or, I should say, cables operating within certain accepted tolerances, between components in somebody's livingroom will differ in sound because of routine jitter. In other words, two Monster cables in good condition at different prices should not result in appreciably different sound quality under ordinary conditions. As N. Ab implies, only when we push usage to the edges do materials and design choices possibly come into play. In still other words, I don't know what EdGein is hearing, and I fear that many of us will never know.

Well that's resolved. Back to you EdG!

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Originally Posted by edtyct

In still other words, I don't know what EdGein is hearing, and I fear that many of us will never know.

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Maybe it's not so much what he heard, but more of what he was smoking when he heard it :ciappa:

Where did Ed/Hershon go, anyway?

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Originally Posted by N. Abstentia

Where did Ed/Hershon go, anyway?

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Don't ask - just enjoy the silience.

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Originally Posted by N. Abstentia

Maybe it's not so much what he heard, but more of what he was smoking when he heard it :ciappa:

Where did Ed/Hershon go, anyway?

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I don't think he realizes there are other threads besides the home theater one so he probably doesn't even know it was moved in here.

Most modern designs re-clock the data, making the jitter discussion irrelevant today but it wasn't always so.

The analog reconstruction filter in any DAC basically works by connecting the dots together. There are 2^16 dots in the amplitude (Y axis) direction or 65, 536 possible values. To acheive the same dot placement acuracy (1 part in 65,000) in the X axis (time) requires a bit to bit acuracy of around 8 pico seconds. Before reclocking was common, this level of bit to bit timing error was common in cables and much worse in the plastic optical cables. Glass cables did much better.

In home stereo, the error correction is almost all in the player or transport, bits are mostly just re-assembled and filtered in most DACs. In the public network, there are often 6 layers of error correction and often entire blocks of data are transimitted more than once (invisible to the end user) which is not possible without RAM buffers in a DAC (A Sony patent using a RAM to prevent skips in car CD players)

Commercial data transmission (the internet) is all over glass fiber. Comparing large scale optical transmission over public networks that have layers of error correction and using glass not plastic fiber and which transmitts data that on the whole is not sensitive to bit to bit timing error and a CD data link is irrelevant. They are just not the same.

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Originally Posted by hermanv

In the public network, there are often 6 layers of error correction and often entire blocks of data are transimitted more than once (invisible to the end user) which is not possible without RAM buffers in a DAC (A Sony patent using a RAM to prevent skips in car CD players)

Commercial data transmission (the internet) is all over glass fiber. Comparing large scale optical transmission over public networks that have layers of error correction and using glass not plastic fiber and which transmitts data that on the whole is not sensitive to bit to bit timing error and a CD data link is irrelevant. They are just not the same.

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yeah, I kind of glossed over that... Well said.

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Originally Posted by orgasmdonor

I have been confused on this issue until today. Some say digital coax some say opitcal for sound. Eddie has stated that you must have an opital cable for best audio. I have been told that the digital coax and opitcal cables both do the same task and not one is better than the other...signal is just transmitted differently..I got two opinions on this. One was by tech support at Best Buy the other from a tech at Crutchfeild both said exactly the same thing not one is better than the other.. To coax vs. optical...The ONLY way the optical cable could be a better source is if you have to run 25 feet or more from one source to the other. Then the optical light would in essence transmit quicker. I doubt any of us would even notice the difference especially if your receiver has auto or manual "lip-sync" capabilites while watching a movie...music only; no difference at all. Please give me your opinions on this subject and what you ahve experienced. Thank you

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It is a digital signal, I.E. 1s and 0s. I prefer coax on runs shorter than 100 feet for cost reasons, that's it. You will be fine with either