[Headphile808]

Quote:

Originally Posted by Maxvla /img/forum/go_quote.gif But really who runs a 25 foot optical cable?

Monster M-Series MLS1000 8M
Aloha

Headphile808

 

[zeroibis]

If you really wanted to know if there is a difference just do the following.
Connect two devices together with said optical cable
Create a stream of 1's and 0's and send it though the cable
Have the receiver configured to output the sequence of 1's and 0's
If the sequence you sent was the same as the one it got than clearly you are not losing any quality...

 

[Maxvla]

They aren't arguing that the data received is not the same, they are arguing that the data is received at different times based on reflections inside the cable.

I don't see how this is possible unless the cable is moving. A stationary cable will reflect every piece of data exactly the same, if the reflection causes a 2ms delay every piece of data will be delayed by 2ms and you still end up with the same exact performance, just the entire stream is delayed in starting and ending by 2ms.

 

[ashmedai]

Quote:

Originally Posted by Maxvla /img/forum/go_quote.gif They aren't arguing that the data received is not the same, they are arguing that the data is received at different times based on reflections inside the cable.

Um, okay. Assuming it's a true statement that the sequence of bits is preserved, but that the t_arrival for each bit differs...

What, it's a clocked signal. As long as you have buffering and the average delay is some small fraction of your signal rate (which, reading the last few posts, it seems to be) - YOU HAVE NO PROBLEM. Also, some variation is expected behavior for any real system - insisting that there should be none is just silly when it's well within meaninglessly small levels.

Snake oil.

(Really, need to remember not to post anything about cables, ever.)

 

[majkel]

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!

Lack of logical thinking is a general inability of cable non-believers. They think they saw proofs all cables are the same while I have never seen such a proof. This is like that - they saw somebody didn't distinguish cable A from cable B. The conclusion is - X is like Y, D is like C, C is like X, ... any combination is lik A against B. Does it make sense?

 

[ashmedai]

Quote:

Originally Posted by majkel /img/forum/go_quote.gif Lack of logical thinking is a general inability of cable non-believers. They think they saw proofs all cables are the same while I have never seen such a proof. This is like that - they saw somebody didn't distinguish cable A from cable B. The conclusion is - X is like Y, D is like C, C is like X, ... any combination is lik A against B. Does it make sense?

I believe in logical circles, your first statement is called a gross generalization (when it's not just referred to as silly - "everyone who disagrees with me is an idiot" tends to be shoddy reasoning at the best of times), and the second is called a strawman argument.

Am I right?

 

[gregorio]

Transfer of digital audio is not a particularly new technolgy. The digital audio stream also contains a great deal of metadata. This metadata includes timing information (embedded word clock) and error correction data. None of this is new, it's been around for more than 20 years and it works! Once the information reaches your DAC or other piece of digital audio equipment it is buffered and the metadata extracted. The internal clock is then synchronised to the word clock data (extracted from the metadata or supplied separately with pro-gear), parity and other error correction is checked before being release in order and in time from the buffer.

So, all this stuff about reflections or the rest of it is all bogus. So if you are happy sitting there with your $100 lightpipe cable enjoy yourself. I will sit here with my $10 cable absolutely secure in the knowledge that there can be no difference to audio quality whatsoever. If you can hear a difference between cables or connector types you either have a fault with the cable or with the equipment it's plugged into.

I personally think it's despicable. Manufacturers know that digital audio is not well understood by consumers and this allows them to take advantage. There are numerous cases where consumer (and even budget pro-gear) manufacturers big up certain specifications when they know that these specifications are going to have absolutely no impact on sound quality but simply allows them to sell additional products with massive profit margins. For professionals like me it makes my blood boil that manufacturers are deliberately mis-leading the consumer and that there doesn't seem to be anything illegal about this practice.

Cheers, G

 

[majkel]

Quote:

Originally Posted by ashmedai /img/forum/go_quote.gif I believe in logical circles, your first statement is called a gross generalization (when it's not just referred to as silly - "everyone who disagrees with me is an idiot" tends to be shoddy reasoning at the best of times), and the second is called a strawman argument. Am I right?

Looks like you didn't understand. As I said before, problems with logical thinking are very coherent with assumptions kind of "cables don't differ, optical fibers don't differ". Have you ever seen a single proof saying all cables must sound the same? Please, show me.
Quote:

]Transfer of digital audio is not a particularly new technolgy. The digital audio stream also contains a great deal of metadata. This metadata includes timing information (embedded word clock) and error correction data. None of this is new, it's been around for more than 20 years and it works! Once the information reaches your DAC or other piece of digital audio equipment it is buffered and the metadata extracted. The internal clock is then synchronised to the word clock data (extracted from the metadata or supplied separately with pro-gear), parity and other error correction is checked before being release in order and in time from the buffer.

Bla, bla, bla. False generalization. First - how can you be sure the digital communication between the two devices is flawless? It is not, maybe it's true in very well built digital transports, but in most cases - it sucks to deliver 100% flawless digital stream. Second - there are several methods of colcking the DAC, and in most cases it is not re-clocking but PLL recovery of the SPDIF data clock. So, the data come more or less flawed, and you have jitter on them, affecting the DAC clocking. Another problem is that you get bad frames from time to time, just because of reflections, transparency loss and dispersion in optical fibers. The data recovery is practically none for SPDIF. Bad frames are rejected which means no data. It's up to the DAC or the SPDIF receiver what to do with such a frame but it's each time made out not recovered.

 

[gregorio]

"Bla, bla, bla. False generalization. First - how can you be sure the digital communication between the two devices is flawless?".

You can't, transferring any signal is always going to degrade it, at least in this universe. Duh, this is why digital audio was invented!! Digital audio doesn't need to be transferred flawlessly to flawlessly reproduce the original signal, that is why it was invented in the first place! Hello, am I getting through here? It doesn't matter if it's a good quality '1' or a bad quality '0' or if the odd '1 or 0' is missing or out of time, digital systems have been designed for over a quarter of a century to expect and deal with these errors. Without this ability there would be no digital audio!

Look, you want to spend $100 on a piece of plastic which is going to make absolutely no difference when compared to a $10 equivalent, you go for it. Share holders are having a hard time at the moment and I'm sure they will appreciate your contribution to keeping them in the lifestyle to which they are accustomed!

Cheers, G

 

[rocker]

I have myself wondered about the value of high end toslink - I love Van Den Hul cables but really wonder how ther Opticoupler could give more.

 

[gregorio]

rocker - I am not arguing that different makes of cable don't have different specifications and some have better specifications than others, I take this as a given. What I and several others, are saying is that the very nature of digital audio and why it was invented in the first place makes the specification of the cable irrelevant. Even the very cheapest cable (providing it isn't damaged or faulty) is going to pass a signal well enough so that the DAC can perfectly recreate the original signal. It's black and white, there is no grey, no better or worse, it either works or it doesn't; if it works, it works as well as any other cable.

G

 

[majkel]

Quote:

Originally Posted by gregorio /img/forum/go_quote.gif rocker - I am not arguing that different makes of cable don't have different specifications and some have better specifications than others, I take this as a given. What I and several others, are saying is that the very nature of digital audio and why it was invented in the first place makes the specification of the cable irrelevant. Even the very cheapest cable (providing it isn't damaged or faulty) is going to pass a signal well enough so that the DAC can perfectly recreate the original signal. It's black and white, there is no grey, no better or worse, it either works or it doesn't; if it works, it works as well as any other cable. G

You are very wrong. If you studied subjects like data transmission or related, you should know that the error rate is never equal zero. You assumed that your digital transmission is 100% correct. I am telling you it is not, even though these are ones and zeros. Take into consideration as well that for the non-reclocking DAC it is very important for how long each logic state is present. The problem is that each audio producer is going with the costs as low as still the error rate is acceptable for statistically huge group of people, taking into consideration the equipment they will use, and statistical hearing. People here averaged, are say, above all globe average.

I tried it for myself what Technics did to the Toslink transmitter - very long traces and just one capacitor 100nF at the optical device. Guess what happened when I soldered another 68uF tantalum capacitor to decouple the transmitter supply. Well, it started to sound more like fed from the Accuphase DP800 transport via a regular, cheap coaxial cable. Why all of that? Just because the digital trasport must be properly build with a good margin of voltage stability and edge steepness of the data to work fine with a less than perfect cable. It's not a big deal, especially for a DIYer but companies make it intentionally to show you the more you pay, the more you get.

In the meanwhile - keep on believing your digital is bit perfect. That is cheaper for sure.

 

[rocker]

I have learned as in all hobbies, YMMV and buyer beware.

 

[gregorio]

"You are very wrong. If you studied subjects like data transmission or related, you should know that the error rate is never equal zero. You assumed that your digital transmission is 100% correct."

majkel - Thank you so much for pointing out what I assumed. Try reading the thread before telling me what I assumed!

G

 

[Currawong]

Quote:

Originally Posted by majkel /img/forum/go_quote.gif Lack of logical thinking is a general inability of cable non-believers. They think they saw proofs all cables are the same while I have never seen such a proof. This is like that - they saw somebody didn't distinguish cable A from cable B. The conclusion is - X is like Y, D is like C, C is like X, ... any combination is lik A against B. Does it make sense?

What gets me is that people will do scientific tests, then deduce things from them that they didn't prove, which is non-scientific.

Quote:

Originally Posted by gregorio /img/forum/go_quote.gif "Bla, bla, bla. False generalization. First - how can you be sure the digital communication between the two devices is flawless?". You can't, transferring any signal is always going to degrade it, at least in this universe. Duh, this is why digital audio was invented!! Digital audio doesn't need to be transferred flawlessly to flawlessly reproduce the original signal, that is why it was invented in the first place! Hello, am I getting through here? It doesn't matter if it's a good quality '1' or a bad quality '0' or if the odd '1 or 0' is missing or out of time, digital systems have been designed for over a quarter of a century to expect and deal with these errors. Without this ability there would be no digital audio! Look, you want to spend $100 on a piece of plastic which is going to make absolutely no difference when compared to a $10 equivalent, you go for it. Share holders are having a hard time at the moment and I'm sure they will appreciate your contribution to keeping them in the lifestyle to which they are accustomed! Cheers, G

I can see by your post you know very little to nothing about how digital audio works, and don't want to know, because that would show the gross flaws in your arguments. Start with the alt.cd-rom FAQ. You might get a rude shock to discover that, for example, ALL CDs are full of errors. But this is the tip of the iceburg.

Incidentally, when I first bought a Van Den Hul Optocoupler, I expected it to make no difference compared to the cheap optical cable I was using. To say that I received a rude shock would be an understatement. That being said, there are DACs and CD players that have DSPs in them that render the differences almost null, but for most people and most DACs, it'll still make a difference.