[myinitialsaredac]

Quote:

Originally Posted by Maxvla /img/forum/go_quote.gif You guys really are nuts. The most error proof connection there is and you still say there is a difference. Enjoy your $100 tubes of plastic.

Optical....error proof? I think you just belittled the value of your opinion in this thread....

Dave

 

[Dr. Strangelove]

Quote:

Originally Posted by Currawong /img/forum/go_quote.gif The great irony is that when people say that ICs make no difference, they quote scientific tests, but when they say that optical digital cables make no difference, they completely ignore science!

Analog interconnects make a big difference because they pass an analog signal. Said analog signal is very fragile as it is a variable voltage, and therefore has an almost infinite amount of states. Because of the almost infinite amount of states, the signal can be effected in an equally infinite amount of ways.

A digital cable makes very little difference: as long as the signal it is passing can be decoded by the receiver (Example here would be LPCM and DAC) then the signal is the same as the source. The voltages might have been rounded off, the amplitude might have been decreased, but it makes no difference because the decoder still knows what it means. The cable only needs to pass two states: maximum voltage, and no voltage. Therefore, it only has two possible states of interference that effect the perceivable outcome: it works or it doesn't work (This is an oversimplification but it does not have bearing on our conclusion).

The only feature of the signal that a better cable will effect is the length you can run the signal before it cuts out.

To quote BlueJeans Cable:
Quote:

But a digital signal, because of the way its information is stored, can be quite robust. While the signal will always degrade to some degree in the cable, if the receiving circuit can actually reconstitute the original bitstream, reception of the signal will be, in the end analysis, perfect. No matter how much jitter, how much rounding of the shoulders of the square wave, or how much noise, if the bitstream is accurately reconstituted at the receiving end, the result is as though there'd been no degradation of signal at all.

 

[ThePredator]

Digital errors wouldn't cause a loss of soundstage or decay, it would literally sound like small chunks of sound were missing or sounds would be created that weren't there (and it would be very noticeable).

If someone shows that a piece of data hashed at each side of a cheap (but still working audibly) toslink fibre cable are different, then I will go buy a Monster fibre optic the next day. Until then (it would be a relatively easy test to do compared to testing analog cables) I will continue to happily use relatively cheap plastic ones.

 

[myinitialsaredac]

Quote:

Originally Posted by Dr. Strangelove /img/forum/go_quote.gif Analog interconnects make a big difference because they pass an analog signal. Said analog signal is very fragile as it is a variable voltage, and therefore has an almost infinite amount of states. Because of the almost infinite amount of states, the signal can be effected in an equally infinite amount of ways. A digital cable makes very little difference: as long as the signal it is passing can be decoded by the receiver (Example here would be LPCM and DAC) then the signal is the same as the source. The voltages might have been rounded off, the amplitude might have been decreased, but it makes no difference because the decoder still knows what it means. The cable only needs to pass two states: maximum voltage, and no voltage. Therefore, it only has two possible states of interference that effect the perceivable outcome: it works or it doesn't work (This is an oversimplification but it does not have bearing on our conclusion). The only feature of the signal that a better cable will effect is the length you can run the signal before it cuts out. To quote BlueJeans Cable:

.5, up or down? .4 up or down? .6 up or down? .499 up or down? .501 up or down? see where I'm going with this?
Your oversimplified version doesn't take into affect dielectric properties.
In optical this is not a problem, but if reflections add jitter, or worse cause the signal to be 70% of the light at a given time, or reflect so 50% arrives at the right time and 50% at a slightly later time then Houston we have a problem. The receiver must make a decision whether it is a 1 or 0.

Your quote from BJC is very accurate, but I think you misunderstood it. It is saying that if a signal arrives, yet it has slight imperfections, but was understood perfectly, than it will sound the same as if it did not have those slight imperfections. It does not say that imperfections can change the sound.

Jitter does not cause huge gaps in time to disappear, it simply causes some of the 44,100 points to be in a different spot by a certain amount. This can manifest itself in more than one way I'd assume. It would effectively be the same affect of misinterpretations on the receiving end for 1s and 0s. It doesn't mean it wont work, but it can cause slight variations in sound. Oversimplifying does not work in this case, because one must consider what these 1s and 0s culminate into, a complex analog wave that is derived from 44,100 points and some interpolation.

Dave

 

[Dr. Strangelove]

From what I have read, jitter introduced by cables of reasonable manufacture and length for audio application is not high enough in amplitude to effect rise and fall times (Of the charge) to the point were a bit is read different vs the source.

In any case, I guess not all optical is created equal... but surely there is a point were the jitter introduced by the cable is not going to effect the signal (and that point is not up in the clouds of 100USD+)?

 

[Maxvla]

This is becoming overly complicated. The receiver would see either no light or some light of any value. Whether it is 70% of the full light or not it doesn't matter.

 

[ThePredator]

Quote:

Originally Posted by Maxvla /img/forum/go_quote.gif This is becoming overly complicated. The receiver would see either no light or some light of any value. Whether it is 70% of the full light or not it doesn't matter.

The claim here seems to be that light transmission is slow and varied enough through cheap fibre optic that it can cause timing issues on MHz clocks.

 

[Devolve]

Quote:

Originally Posted by ThePredator /img/forum/go_quote.gif The claim here seems to be that light transmission is slow and varied enough through cheap fibre optic that it can cause timing issues on MHz clocks.

$2 cables deserve some sort of award then for slowing down the speed of light.

 

[RickEC]

Signal amplitude doesn't matter as discussed. The speed of light does not have to change for cables to mess with the timing of the signal. These are just theories on paper. If you cannot hear the difference, then don't bother.

 

[gadgetman]

I'm a newbie, though I'm somewhat familiar with the technical aspect of data transfer and codec formats... I've a question about digital optical audio:

I assume the format of data in question being bitstreamed thru said optical cables are RAW PCM Stream?
Does that have any error correcting capability?

 

[myinitialsaredac]

Quote:

Originally Posted by Maxvla /img/forum/go_quote.gif This is becoming overly complicated. The receiver would see either no light or some light of any value. Whether it is 70% of the full light or not it doesn't matter.

.7 up or down? .5 up or down? .1+.3 up or down? .3+.023+.58+.2 up or down? Do you understand the complexity yet? Any reflections can cause light to arrive at slightly different times, where it may be arriving with other reflections or other signals.
Your oversimplifying something far beyond where it can be oversimplified too.
Dave

 

[myinitialsaredac]

Quote:

Originally Posted by gadgetman /img/forum/go_quote.gif I'm a newbie, though I'm somewhat familiar with the technical aspect of data transfer and codec formats... I've a question about digital optical audio: I assume the format of data in question being bitstreamed thru said optical cables are RAW PCM Stream? Does that have any error correcting capability?

It does not have any error correction because there is no 2 way transmission in an optical cable. One transmitter, one receiver.

Dave

 

[Dr. Strangelove]

Quote:

Originally Posted by gadgetman /img/forum/go_quote.gif I assume the format of data in question being bitstreamed thru said optical cables are RAW PCM Stream?

Actually, it is Spdif format: clock + stream.

 

[krmathis]

Quote:

Originally Posted by Maxvla /img/forum/go_quote.gif You guys really are nuts. The most error proof connection there is and you still say there is a difference. Enjoy your $100 tubes of plastic.

They may sound the same, but still not be created equal...

I am certainly enjoying my $150 cable.

 

[Devolve]

Quote:

Originally Posted by myinitialsaredac /img/forum/go_quote.gif Any reflections can cause light to arrive at slightly different times, where it may be arriving with other reflections or other signals. Dave

Are these "slightly different times" even detectable at the speed of light?