High Quality USB Cable for USB DAC?
Apr 12, 2009 at 2:59 PM Post #91 of 129
All this talk about the usb cables effect on the audio quality, does the same apply to power cords? How about interconnects and speaker cables?

As a former computer technician I find it somewhat hard to come to terms with the statement that different usb cables sounds differently
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However, I've read some rather good articles about the subject and understand that the cables shielding might affect its sound characteristics. Some say "a usb cable is a usb cable". Others say that a usb cable works differently depending on its use. In data transfer to a external HDD, the cable doesn't matter -but in a audio streaming situation it does...

In the same line of thoughts I wonder how can it be that a different power cord affects a speakers bass output
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To me, "a power cord is a power cord". I do however acknowledge that a good shielded power cord will resolve any humming, hiss and static from the sound. I guess the same applies to a usb cable and that's were the different sonic signatures comes to play. Or does it?

Could it simply be that Hi-Fi manufacturers have found yet another way of stealing our money
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I will try to find a local dealer with a good stock of different usb cables and try it for myself...
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...by the way, I guess this type of discussions were all over the scene a few decades ago when high end speaker cables started to appear
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Apr 12, 2009 at 4:37 PM Post #92 of 129
Quote:

Originally Posted by Kobra /img/forum/go_quote.gif
However, I've read some rather good articles about the subject and understand that the cables shielding might affect its sound characteristics.

In data transfer to a external HDD, the cable doesn't matter -but in a audio streaming situation it does...



All very logical apart from one simple fact, the USB is not passing any audio, so it's sound characteristics are completely irrelevant. Why do you think that data transfer to external HDD makes no difference what USB cable you use but streaming digital audio data does? What is the difference between a stream of zeros and ones going to your HDD and a stream of zeros and ones going to your DAC?

What is the next thread after this one, which make of Hard disk sounds better to stream your digital audio from? It's no less of a valid question than which USB cable sounds better.

G
 
Apr 12, 2009 at 7:01 PM Post #93 of 129
Bits are bits. If our transmission is reliable, we receive exactly the same bits as has been send.
But we are not talking about sending bits from a computer to a hard disk, we talk audio. In case of a stone age protocol like SPDIF it is simple, the bits are the signal and the sample rate is derived from the speed at which the bits are pouring in. Any variation in the bit rate will cause a fluctuation in the DA conversion (jitter).
USB is a more complex protocol but again it send the signal as bits and the sample rate is derived from the data. There are claims that USB could induce input jitter and this might map to sample rate fluctuations in the DA conversion.
I do not claim that cables will make a difference but I do claim that looking at the bit part only is neglecting the other half of the equation: the timing.
That’s the paradox of digital audio, the signal is represented in bits, the timing is (most of the time) derived from a clock, an analogue device with all of its analogue imperfections.

A rather interesting discussion about the merits of high end digital cables can be found here: PSW Recording Forums: Dan Lavry => Why longer is generally better for an S/PDIF Digital Cable
 
Apr 12, 2009 at 7:37 PM Post #94 of 129
Quote:

Originally Posted by gregorio /img/forum/go_quote.gif
All very logical apart from one simple fact, the USB is not passing any audio, so it's sound characteristics are completely irrelevant. Why do you think that data transfer to external HDD makes no difference what USB cable you use but streaming digital audio data does? What is the difference between a stream of zeros and ones going to your HDD and a stream of zeros and ones going to your DAC?

What is the next thread after this one, which make of Hard disk sounds better to stream your digital audio from? It's no less of a valid question than which USB cable sounds better.

G



Please understand that I'm only quoting others - it's not my words. I'm very much on the fence regarding usb cables and audio. My earlier posts in this thread is just my way of "thinking out loud" so I can come to a understanding.
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Apr 13, 2009 at 4:49 AM Post #96 of 129
Anyone who spends more then $10 on a USB cable is a sucker. IMO.

The encoded audio data sent over a $10 cable can not possibly sound any different then sent over a $100 or $1000 one.
 
Apr 13, 2009 at 8:48 AM Post #97 of 129
Quote:

Originally Posted by gregorio /img/forum/go_quote.gif
All very logical apart from one simple fact, the USB is not passing any audio, so it's sound characteristics are completely irrelevant. Why do you think that data transfer to external HDD makes no difference what USB cable you use but streaming digital audio data does? What is the difference between a stream of zeros and ones going to your HDD and a stream of zeros and ones going to your DAC?

What is the next thread after this one, which make of Hard disk sounds better to stream your digital audio from? It's no less of a valid question than which USB cable sounds better.

G



USB audio specifications are based on a 'streaming' system, which is different from a 'block' based system used in conventional data transfer.
 
Apr 13, 2009 at 12:07 PM Post #98 of 129
Quote:

Originally Posted by Roseval /img/forum/go_quote.gif
In case of a stone age protocol like SPDIF it is simple, the bits are the signal and the sample rate is derived from the speed at which the bits are pouring in. Any variation in the bit rate will cause a fluctuation in the DA conversion (jitter).
USB is a more complex protocol but again it send the signal as bits and the sample rate is derived from the data. There are claims that USB could induce input jitter and this might map to sample rate fluctuations in the DA conversion.
I do not claim that cables will make a difference but I do claim that looking at the bit part only is neglecting the other half of the equation: the timing.
That’s the paradox of digital audio, the signal is represented in bits, the timing is (most of the time) derived from a clock, an analogue device with all of its analogue imperfections.

A rather interesting discussion about the merits of high end digital cables can be found here: PSW Recording Forums: Dan Lavry => Why longer is generally better for an S/PDIF Digital Cable



Again, all very logical sounding but complete nonsense. Have you ever heard of a PLL? A phase locked loop (Phase-locked loop - Wikipedia, the free encyclopedia) eliminates the jitter, so there are no fluctuations in the DA conversion. Jitter during transfer is a complete non-issue, a red herring. Advertising of expensive digital cables often mention jitter but conveniently forget to mention that it doesn't matter because the PLL removes it all!! BTW, VCOs are used to generate the timing signals in PLLs, not an analogue clock.

Also, nice link, which in fact states the complete opposite of what you are implying. The page you linked to was where a Steve N (who is also on this site) explains why his digital cables are better. The rest of the thread contains posts by audio professionals who absolutely destroy virtually every argument put forth by Steve N. It was one of the best debunking of a cable manufacturer I've ever seen and poor Steve N had to run away with his tail between his legs once he realised that he had made a mistake by trying to fool the professionals the way he fools consumers. Here is what Dan actually wrote in that thread:

"This article is a bunch of nonsense! Longer is NOT better. SHORTER IS BETTER! That is unless you are the one selling cables, and you charge a lot and by the foot
frown.gif


Check the website of that Empirical Audio guy:
Home : Empirical Audio
You will quickly understand that he stands to benefit from that B.S.

For a 1 meter SPDIF he charges 419.99$
For a 1.5 meter SPDIF he charges 549.99$
For a 2 meter SPDIF he charges 679.99$

You will find B.S. “explanations” such as:
“The Bitmeister uses a patented technology that allows the conductors to be 50% bare. Bare conductors cause less dispersion (smearing) in the digital signal” than fully insulated conductors, reducing jitter in the digital signal".

“Pure 99.99% Perfect Crystal Silver conductors in
a custom stranded configuration enhance high-frequency response
by minimizing skin-effect and stranding effects”.

What a bunch of self serving nonsense
frown.gif


Regards
Dan Lavry
www.lavryengineering.com"

Quote:

Originally Posted by acetylcholine /img/forum/go_quote.gif
USB audio specifications are based on a 'streaming' system, which is different from a 'block' based system used in conventional data transfer.


And what difference does it make? In the case of a HDD the data is stored in an on-board buffer before being written to the disk and in an audio output device the data is stored in an on-board buffer before being sent to the PLL and then on to the DAC.

G
 
Apr 14, 2009 at 11:53 AM Post #100 of 129
You know its funny but the cable guys and the hifi guys all go on and on about jitter. If you beleived what they said about it you'd expect any digital audio to sound like a coffee grinder.

But I always ask them (Steve N included) "well if its so bad then how do you quantify it or describe it as part of the listening expereince? What should I be listening for? Its all sounded pretty good for me these past 20 years!"

It all goes very very quiet at that point. Its just FUD to charge you more.
 
Apr 14, 2009 at 6:20 PM Post #101 of 129
^ Yeah, you'd think jitter was some mystical force. Apparently my Optical S/PDIF is overflowing with it.
 
Apr 14, 2009 at 9:27 PM Post #102 of 129
Quote:

Originally Posted by daglesj /img/forum/go_quote.gif
You know its funny but the cable guys and the hifi guys all go on and on about jitter. If you beleived what they said about it you'd expect any digital audio to sound like a coffee grinder.

But I always ask them (Steve N included) "well if its so bad then how do you quantify it or describe it as part of the listening expereince? What should I be listening for? Its all sounded pretty good for me these past 20 years!"

It all goes very very quiet at that point. Its just FUD to charge you more.



Laughing my ass off at the coffee grinder analogy, there's far too much focus on jitter, especially after reading about the PLL linked above. I can't believe how stalwartly some people defend digital cables since the sound coloration thing is out the window when you're talking 1's and 0's. Personally I don't notice a difference with analog cables either, I have a cheap as can be mini-RCA cable and there's absolutely no difference with the BJC in my setup. There's certainly nothing wrong with spending a few dollars on a cable with nice build quality and looks though.

Quote:

Originally Posted by Chri5peed /img/forum/go_quote.gif
^ Yeah, you'd think jitter was some mystical force. Apparently my Optical S/PDIF is overflowing with it.


Don't forget that your signal is destroying itself through internal reflection, the plastic fibers aren't optically conductive enough, and your wireless router is talking to it with RFI.
 
Apr 14, 2009 at 10:07 PM Post #103 of 129
I have a short Locus Design Axis USB cable connecting my Trends UD-10.1 to my laptop. I have some experience picking out subtle differences in sound quality and while I haven't done any real tests yet I can say there are no obvious improvements that I can hear compared to the cable that came with the Trends.

However, my setup isn't the best for comparing usb cable quality yet since the cable goes into a usb to spdif converter and a spdif cable from Blue Jeans cable goes into my dac. I'm hoping to try out an Ayre usb dac later this year and then I would be able to conclusively say there's no audio quality difference between usb cables.

As of now I would say if you're concerned about the audio quality of your freebie usb cable, get a $20 Belkin cable and be done with it. Like most expensive cables, the Locus Axis is impressive to look at and has quite a bit of bulk to it, but I'd recommend spending the money on speakers, a dac, preamp, amps, and rca/xlr interconnects first (and probably in that order). Digital interconnects would be way down the list.

For me, it was worth buying to confirm that it makes no difference. If any of you want to try it in your system to see if it does anything for you, feel free to make me an offer for the cable.
 
Apr 14, 2009 at 10:18 PM Post #104 of 129
Quote:

Originally Posted by gregorio /img/forum/go_quote.gif
Jitter during transfer is a complete non-issue, a red herring. Advertising of expensive digital cables often mention jitter but conveniently forget to mention that it doesn't matter because the PLL removes it all!! BTW, VCOs are used to generate the timing signals in PLLs, not an analogue clock.


Quote:

Originally Posted by daglesj /img/forum/go_quote.gif
You know its funny but the cable guys and the hifi guys all go on and on about jitter. If you beleived what they said about it you'd expect any digital audio to sound like a coffee grinder.

But I always ask them (Steve N included) "well if its so bad then how do you quantify it or describe it as part of the listening expereince? What should I be listening for? Its all sounded pretty good for me these past 20 years!"



I can't say I'm an expert on jitter or digital audio transports, but I can say that all of the usb audio implementations I've heard so far are very audibly inferior to a cd player. I find a good cd player to be much crisper sounding. All sounds decay faster and have more attack or punch to them. All usb audio blurs the sound. It's very noticeable in my system. I suspect the difference in sound quality is differing levels of jitter in the usb stream compared to the internal jitter in the cd player. I suppose there could be other factors, but jitter sounds like the most likely reason for the difference I'm hearing (especially since I tried other usb cables and found no difference). Digital audio from a transport connected through optical also sounds similar to usb audio in my system.

I want to get usb audio to sound as good or better than my cd player because I much prefer the convenience of playing music on my computer, but so far I haven't been able to get the audio quality there yet.
 
Apr 14, 2009 at 10:31 PM Post #105 of 129
Quote:

Originally Posted by Mik /img/forum/go_quote.gif
I can't say I'm an expert on jitter or digital audio transports, but I can say that all of the usb audio implementations I've heard so far are very audibly inferior to a cd player. I find a good cd player to be much crisper sounding. All sounds decay faster and have more attack or punch to them. All usb audio blurs the sound. It's very noticeable in my system. I suspect the difference in sound quality is differing levels of jitter in the usb stream compared to the internal jitter in the cd player. I suppose there could be other factors, but jitter sounds like the most likely reason for the difference I'm hearing (especially since I tried other usb cables and found no difference). Digital audio from a transport connected through optical also sounds similar to usb audio in my system.

I want to get usb audio to sound as good or better than my cd player because I much prefer the convenience of playing music on my computer, but so far I haven't been able to get the audio quality there yet.



You know what I think your problem is? Its not the gear. No, not the gear.

It's you.

You are trying soooo hard to listen to the hardware, you are forgetting the most important part. Just listening to the tunes instead. You are worrying about stuff that really isnt that important and its spoiling your enjoyment.

Its not your fault, you've been told that this kind of thing should happen, mainly by people who sell $800 digital cables and $2000 DACs.

There is a huge difference. Once you listen to the music rather then the hardware it sounds 1000000 times better.

There is no better upgrade or tweak. And its free.
 

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