Don't get why "Audiophile" USB Cable would improve sound quality

May 19, 2011 at 9:15 AM Post #46 of 835
Quote:
If a cable (are there any on sale?) distorts the waveform such that it cannot recover the timing signal, then surely it would stop working rather than affect sound quality?
 
When I say stop working I mean even if it just for a part of a second and it introduces a crackle or other sound that is not part of the music. Not just if the signal comes to a complete halt.


It doesn't work that way. The signal timing is recovered from the edges of the packets. If the edge of the packet isn't square enough (something a cable could potentially influence), you introduce incertainty in the recovered clock, but it's not like you don't have a clock, you just have a jittery one. The protocol is sufficiently robust to work within such incertainty and to reduce it to a certain extent (that's the job of a PLL). However, those variations in the time domain will translate as distortions at the analog output (not as crackle or pop). The math for that is in some papers I've posted in the other threads (about spdif but the reasonning is the same). That's why some usb cables with big ferrites are fine for data transfers but might be problematic for usb audio transfer, as they "round"  the edges of the packets.
 
Still, my point of view is that interface jitter introduced by a short, decent cable is no big deal. I myself use a cable grabbed from an old HP printer.
 
May 19, 2011 at 9:47 AM Post #47 of 835
I understand about the clock part of the signal and the issue of jitter.
 
But jitter is another possible red herring as it has yet to be shown how jitter affects sound quality, it is just assumed it does. If there is a case where jitter is so high it does affect the sound and that level of jitter is down to the cable, I would argue the cable is faulty. I do not think DAC/cable makers are at a position yet to be able to say for certain that jitter reduction, particularly where with well made kit it is so low anyway, is needed to improve sound quality.
 
Irrespectively, this is a discussion about USB cables and their supposed affect on sound. Is there evidence that a USB cable can introduce jitter, or is not a problem between the source and receiver? So the cable has no effect.
 
May 19, 2011 at 1:00 PM Post #50 of 835
I don't get why either but it does sound better.  I've got the Cardas Clear USB.   Cost me about $100.  All the $$$ I've spent $100 isn't going to kill me.  Looks better if I peek in the back too!
 
May 19, 2011 at 5:35 PM Post #51 of 835

Quote:
I don't get why either but it does sound better.  I've got the Cardas Clear USB.   Cost me about $100.  All the $$$ I've spent $100 isn't going to kill me.  Looks better if I peek in the back too!


Nice to see someone crawling out of the mystical audio science cocoon and uses their ears instead =)
 
 
May 19, 2011 at 7:35 PM Post #52 of 835
Quote:
I understand about the clock part of the signal and the issue of jitter.
 
But jitter is another possible red herring as it has yet to be shown how jitter affects sound quality, it is just assumed it does. If there is a case where jitter is so high it does affect the sound and that level of jitter is down to the cable, I would argue the cable is faulty. I do not think DAC/cable makers are at a position yet to be able to say for certain that jitter reduction, particularly where with well made kit it is so low anyway, is needed to improve sound quality.
 
Irrespectively, this is a discussion about USB cables and their supposed affect on sound. Is there evidence that a USB cable can introduce jitter, or is not a problem between the source and receiver? So the cable has no effect.

 
Well, it is perfectly demonstrated "how" jitter introduces distortion. The problem is more "how much" jitter affects sound quality audibly. Go read my very first post again for my position on that wrt usb cables.
 
And there seems to be measured evidence that USB cable can increase the level of jitter. Check if you can get your hands on the January issue of Hifi news for the article by Paul Miller (I can't sadly); from what I gathered in various places on the web, he shows differences in between various cables jitter measurements and at least one "audiophile" usb cable measuring worse than a stock cable.
 
In an earlier article (december 2010, which I've got), he shows how jitter goes from 300ps to 3ns depending on whether or not the power supply of his laptop is attached to the laptop or not. I doubt though that cables would have such drastic effect but it goes to show how the USB audio protocols is far of being without problems.
 
May 19, 2011 at 7:35 PM Post #53 of 835


Quote:
Nice to see someone crawling out of the mystical audio science cocoon and uses their ears instead =)
 


Yea, for an audio forum we have an awful lot of people who refuse to use their ears. Everyone who's heard my system (even my non-audiophile friends) have been surprised when I told them that there are still Head-Fi members who don't believe in cable differences. To them, it was that obvious, and from a short audition too (and without me saying anything about the topic before hand).
 
May 19, 2011 at 9:26 PM Post #54 of 835
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Yea, for an audio forum we have an awful lot of people who refuse to use their ears. Everyone who's heard my system (even my non-audiophile friends) have been surprised when I told them that there are still Head-Fi members who don't believe in cable differences. To them, it was that obvious, and from a short audition too (and without me saying anything about the topic before hand).



I think for most, analogue cable differences are acceptable but digital cable differences (coaxial, toslink, usb, hdmi) are unacceptable for almost 99% of the population here.
 
May 19, 2011 at 9:37 PM Post #55 of 835


Quote:
I think for most, analogue cable differences are acceptable but digital cable differences (coaxial, toslink, usb, hdmi) are unacceptable for almost 99% of the population here.



I will admit that digital cable differences were smaller than analog (IME). I've tried both USB and coaxial.
 
May 19, 2011 at 9:41 PM Post #56 of 835


Quote:
Nice to see someone crawling out of the mystical audio science cocoon and uses their ears instead =)
 


Technically, you aren't using your ears. You are also using your eyes, and preconceived notions of what you should hear. If you know what cable you are using, then you are not using just your ears. I would bet that if you used JUST your ears, all of the "differences" you claim to hear, would go away. 
wink.gif

 
May 19, 2011 at 10:23 PM Post #57 of 835


Quote:
Technically, you aren't using your ears. You are also using your eyes, and preconceived notions of what you should hear. If you know what cable you are using, then you are not using just your ears. I would bet that if you used JUST your ears, all of the "differences" you claim to hear, would go away. 
wink.gif

 

 
tmars78. You need not tell me this.
 
This is the typical reply one will get from those who do not believe digital cables will make any difference. Many have told many others this and a search in this forum, or any other, will reveal this statement you have just made.
 
I have rejected many branded expensive cables (silver or crystal or whatever) for simple, cheap and well-built copper cable because they just sounded better. Price, brands, marketing gimmicks will trick many people. No doubt about that. Also, I will have to agree that there are too many snake oil cables out there costing a bomb and yet does nothing to improve the sound. People who fell for these tricks will be convicted that digital cables are all but a hoax. But, there are cheaper yet good digital cable that will improve the sound.
 
So far those who argued for the case of no-difference in digital cables do so in the name of science and have not heard for themselves.
Those who argued for the case of difference in digital cables have actually own/heard of it themselves.
 
Placebo effect? Preconceived prejudice on cheap cables?
 
I am not sure if results from a short blind ABX test can be conclusive, especially when the source and the acoustic environment is unfamiliar to someone. Having the cables plugged into your system for a few months and then take it out to see what can one now not be able to hear from their favorite tracks might be a better way to conclude.
 
I don't trust professional reviews and all those fancy specs on cables myself and I will be part of those who will gently snigger at those who actually bought the ~USD4k Locus Design cables myself (unless I am Abramovich of course)
 
 
Nonetheless, I am glad for those who actually take the first step out to get a good USB cables (not snake oil or cheap marketing gimmicks like monster/kimber) to prove the hypothesis which good USB cables make no difference is true.
 
If I can prove that or design a way to make people realize their digital cable actually make no difference, I could open an audio healing clinic to treat people suffering from placebo and earn big bucks and make many big brands' digital cable business wings close down. That might be a good business that I could venture into when I graduate =)
 
Parroting what many others have said and thereby firmly concluding that digital cables make no difference add no value at all.
 
May 19, 2011 at 11:30 PM Post #59 of 835
Looking at the setups used with the "Cables make a difference" group, its not even an audio signal at that point, its strictly a data stream. If you had a USB cable going OUT from your DAC to <insert device name> there could easily be a difference. Right now, I have a small no name ethernet cable going from a modem to my computer. I never have any dropped packets. Will upgrading the cable to one of these change the way I download content? Will an iTunes song downloaded with one change the sound compared to my cable? It will not, because its not audio at that point. Its just a data stream that needs to be compiled and decoded first. The audio cannot even begin to be decoded until all the data required (this doesnt mean the full track) has been transmitted. Pretty much everyone here spent money on a DAC, yet those arguing that USB cables make a difference apparently have no idea on what a DAC does.
 
But, in order to stay open minded, has anyone taken the time to objectively test whether or not there is a difference (frequency differences, etc)?
 
May 20, 2011 at 12:09 AM Post #60 of 835
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I use Dayton 1M usb cables and Dayton 1.5ft and 3ft digital cables.  Are they "good" cables?



@USG: I don't know. I use monoprice cables as the baseline for my comparison since they are pretty affordable, well-built, and widely known. I love them because they perform the job well. But there is something I do not comprehend (as well as all the people out there) as to why digital cables make a difference. I am open to criticism and will even welcome people to my place to have a listen to the difference together. It is a discovery on my part and I am constantly seeking answer to that (which is why I hang around thread like this).
 
@ The Pell: I think it has been discussed before that there is no error correction in USB audio compared to USB data and in audio streaming timing is important. The length and type of USB cables we use for printer/harddrive doesn't really matter but we gotta be careful when using a 5m long USB cable for our DAC. Our USB port pushes real-time data stream out and the DAC pulls them in via USB (or any other digital cables). What happens in between is of interest.
 

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