Check the archives here at Audiogon and Audio Asylum. This topic has been discussed to death over the last dozen years.
And I agree, transports and cables have an impact on the sound. |
The better technical articles that I've read on this subject conclude that interconnects do make a difference, but not for the same reasons that IC's affect the fidelity of an analog signal. Most of the articles I've read state that the primary factor that affects IC's carrying a digital signal is the impedance. The "best" digital cables are those with a 75 ohm impedance (which apparently minimize the reflection of the signal back toward the signal source), while cables that have a higher impedance "bounce" the signal, causing distortion. |
010101 may not sound like 0 1 0 1 0 1. |
Picking up on your last paragraph, I'd say you are probably just hearing things in this case. (Which doesn't mean you're crazy, by the way. Tests show that humans have a tendency to hear differences even when none exist.) There probably are some really bad cables out there that actually make a muck of things, though I suspect badly designed transports and DACs are more likely the culprit, if indeed there is a culprit. But audio is simply not a data-intensive application, so getting it right is close to trivial for engineers who know what they're doing. |
What about comparing a low dollar laser/pickup to a high dollar one. Would there not be a few 1s and 0s lost here and there? Or misinterpreted somehow?
I didnt mention DACs as thats too obvious, in my comparisons the Speakers, Amps, Preamps, Cables, everything from the outboard DAC on stayed the same. All the obvious culprits didnt change, just the digital domain stuff.
It stands to reason that as long as the transport succesfully gathers data from the disc, it wouldnt matter how poorly designed it is. But clearly it does.
And yeah Hpshps, I read a bunch right here under the "Cables" forum. Its just that this is a fun topic for me. =) |
You answered it yourself. Everything makes a difference. |
During last decade or two there were those who worried about 1's and o's while some of us were happily listening to vinyl, it does not even have the error correction system (adding 1's and 0's on its own)
Someone said "There are 10 kinds of people in this world, those who know binary and those who don't"
Happy listening...and hope you don't miss any beat! |
Unsound...The electrical signal that transmits digital data (a pulse train) can be greatly distorted, and the receiver can still reconstruct the original data perfectly,
Your example: 010101 vs 0 1 0 1 0 1. I believe you are thinking of jitter.
How about 16 bits: 01 0 10 1 0 1 01 01 010 1.
If the receiver outputs 16 bit words to its D/A at uniform intervals based on its own clock, it doesn't matter how irregular the incoming serial data transmission was.
Furthermore, some of the zeros can be misread as ones, and the correct original word can still be recognized, thanks to the error correcting encoding of the data, but that's another topic. |
Vinyl has its own set of problems. |
I'm not so sure about the common explanations for sonic differences caused by cables («impedance») and transports («jitter»). My own experiences with digital cables tell me that impedance isn't the decisive factor, there are others, like materials used and conductor geometry/profile. I found the sonic impact of transports to be even clearly higher than with cables. Given that many good transports have very similar jitter patterns on a low level, I don't think that jitter should be seen as solely responsible for the sonic differences, which according to my experience often appear in the level of the sound balance -- which seems to be impossible anyway, looking at the even frequency responses measured with DACs, independent of the connected transports.
Believe me, the differences are real, not imaginated, and very obvious in the case of transports. Well, the mentioned explanation attempts obviously are the only ones available at present, so it's logical to give them a certain plausibility. But this shouldn't be mixed up with assured knowledge.
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Ed Meitner has some good articles on this subject on the web, especially an interview with him I read, by one of the major magazines. It's on the web. |
Eldatford, yes, I was thinking about jitter. Yes, if everything works perfectly, but, even in a self diagnosing system things don't always work out perfectly. |
I am quite happly with my system's audio quality and I don't feel the urge to spent $6000 or so to find out if an esoteric player would sound better. (I have other interests to spend money on).
It's true that my experience with digital communications is in the context of very high-tech military equipment (missile guidance systems) and the techniques that we use may not always be utilized in audio equipment, although I can't see why not since the cost of doing things right would not be great.
In summary, to address the wrong ideas that I hear most often...
digital pulse distortion, be it pulse shape due to line reflections, or timing (jitter) should have no effect.
Error correction is not bad. The purpose of error correction is not to correct errors. It is to permit higher bandwidth communications by operating the hardware so fast that (correctable) errors do occur. You give away, say 50%, of your bandwidth to redundancy, so that you can run, say 5 times, faster.
D/A non-monotonicity would cause audible distortion, but I am not aware of this being a problem with modern electronics. |
Eldatford, I didn't mean to suggest relative value and how you should spend your money. |
A digital signal is still a signal, that is, a time-variable voltage/current presence on the wires. I think here is an important distinction: If the device interpreting the signal treats it as just a sequence of data-bits, buffers it, and then creates an analog signal based on its own internal clock, then sure, 1s will be 1s and 0s will be 0s. But if the time variation of the original signal has an effect on how the device responds, the that signal is essentially sending extra analog information to it as well. |
nonterminatingdecimal@hotmail.com....Exaxtly. |
Well it seems we agree for the most part that changes in transport, cabling, etc, can/do have an effect on sound.
Just recently I purchased a Jolida JD-100. A fine sounding unit BTW. I had been using a Rotel RCD-971. Also a fine unit. Comparing the two, as transports only via a Theta DAC, clearly the Jolida had more firm and powerful bass.
I surmise that such variables as RF and other introduced "noise" could travel along with the data, thus "muddying" or confusing the DAC. Among many other plausible explanations.
I also surmise that there is a bit of "magic" involved as well. The end product(Stereophonic sound) truly is more than a sum of its parts(data). This occurs quite frequently in the world of Quantum physics, when the variables of time and space enter the equation. Clearly Stereophonic Music has these variables. Hmmmm.
It would be interesting to compile results from a Monophonic listening. e.g. Comparing qualitative differences of different cables and transports while listening to mono recorded sources played back in mono. I am curious just how profound or obscure differences would be in comparison to Sterephonic observations. A proof of the "magic" so to speak. Double Hmmmmm.
Just something to ponder.
Thanks to all the posters for a very enlightening read. |
