Gordon Rankin Says I'm Wrong About USB Cable Sound!

[gmgraves]

Mea Culpa, I guess. I just had a nice discussion with Gordon Rankin of Wavelength. Gordon is the man who designed the Ayre QB-9 and the AudioQuest DragonFly DAC, as well as the WaveStream® IsoSynchronous USB protocol. He said a number of things that really took me aback. The first thing he said was that yes, USB cables do sound different. They shouldn't but they do. He says the reason is because most manufacturers are unable or unwilling to make their cables with the correct 90 Ohm impedance and be able to pass up to a 2.6 GHz perfect square wave. He says that unless those two parameters are met, the USB feedback mechanism doesn't work because reflections get the signal confused on the computer end. Without it, there's no way for the computer to know that it's sending the data at the proper rate and bits get dropped. Since USB receivers have no error correction (this was news to me) a dropped bit gets interpolated at the DAC, and distortion increases. He says that this situation is not helped by the fact that Windows, including Win 8, generate 12% more hard errors in a digital audio bitstream than does Apple's OSX! He also says to play your computer audio directly from memory for lowest error rate on either platform, and if possible, keep your music on a Firewire, eSATA or Thunderbolt drive rather than USB.

So, If you want your computer sourced digital audio system to sound it's best, find a cable manufacturer that will guarantee his cable's impedance at 90 Ohms* and that his cable can pass, ideally, a 2.6 GHz, or at least a 0.5 GHz perfect square wave (seems like a pretty high frequency to me), and that your music server runs OSX rather than Windows.

 

*Gordon also told me that virtually NONE of the cable manufacturers out there have any way of measuring the impedance of their cables and many believe that a lower than 90 Ohms is preferable because it allows them to sell longer runs. He says that because any deviation from 90 Ohms (higher or lower) is damaging to the data stream, lowering the impedance of the cable doesn't work. Also, an apps engineer at Belden just told me that most cable companies buy their actual wire from suppliers who will customize things like sheath color and dielectric material, and it's possible that many suppliers supply essentially the same cable to multiple audio cable makers.

[tranz]

Not surprising at all. Same story for ethernet cables.

 

USB has always been a shitty bandaid with the consumer having to go to great lengths and expense to make computer audio bearable.

 

Hopefully the renderer solution will finally mature so we can take USB, and SPDIF for that matter, out of the equation.

 

Cheers

[Skeptic]

He says the reason is because most manufacturers are unable or unwilling to make their cables with the correct 90 Ohm impedance and be able to pass up to a 2.6 GHz perfect square wave. He says that unless those two parameters are met, the USB feedback mechanism doesn't work because reflections get the signal confused on the computer end.

Do you know why they need to pass 2.6GHz?

 

From doing a very quick search, it would appear that USB1 operates up to 12MHz (0.012 GHz) and full speed USB2 (480Mbps) operates at 24MHz. (0.024 GHz)

 

You won't find many cables that are even certified for USB 2.0 speeds, and certainly not 2.6GHz.

 

The cables I use are rated to 1200Mbps, which would appear to be around 60MHz - nowhere close to 2.6GHz.

 

I don't think USB3 cables even start to approach those speeds either, and it's difficult to find certified USB3 cables - not that you can use them with your older devices anyway.

 

He says that this situation is not helped by the fact that Windows, including Win 8, generate 12% more hard errors in a digital audio bitstream than does Apple's OSX!

I would be very interested in seeing proper testing on this, on the same hardware.

 

He also says to play your computer audio directly from memory for lowest error rate on either platform, and if possible, keep your music on a Firewire, eSATA or Thunderbolt drive rather than USB.

Well you can't do anything but play from memory. Files are never really played back from the storage device, they get decoded into RAM first.

 

So, If you want your computer sourced digital audio system to sound it's best, find a cable manufacturer that will guarantee his cable's impedance at 90 Ohms* and that his cable can pass, ideally, a 2.6 GHz, or at least a 0.5 GHz perfect square wave (seems like a pretty high frequency to me), and that your music server runs OSX rather than Windows.

I don't think such a thing exists.

[Mark Manner]

Mea Culpa, I guess. I just had a nice discussion with Gordon Rankin of Wavelength. Gordon is the man who designed the Ayre QB-9 and the AudioQuest DragonFly DAC, as well as the WaveStream® IsoSynchronous USB protocol. He said a number of things that really took me aback. The first thing he said was that yes, USB cables do sound different. They shouldn't but they do. He says the reason is because most manufacturers are unable or unwilling to make their cables with the correct 90 Ohm impedance and be able to pass up to a 2.6 GHz perfect square wave. He says that unless those two parameters are met, the USB feedback mechanism doesn't work because reflections get the signal confused on the computer end. Without it, there's no way for the computer to know that it's sending the data at the proper rate and bits get dropped. Since USB receivers have no error correction (this was news to me) a dropped bit gets interpolated at the DAC, and distortion increases. He says that this situation is not helped by the fact that Windows, including Win 8, generate 12% more hard errors in a digital audio bitstream than does Apple's OSX! He also says to play your computer audio directly from memory for lowest error rate on either platform, and if possible, keep your music on a Firewire, eSATA or Thunderbolt drive rather than USB.

So, If you want your computer sourced digital audio system to sound it's best, find a cable manufacturer that will guarantee his cable's impedance at 90 Ohms* and that his cable can pass, ideally, a 2.6 GHz, or at least a 0.5 GHz perfect square wave (seems like a pretty high frequency to me), and that your music server runs OSX rather than Windows.

 

*Gordon also told me that virtually NONE of the cable manufacturers out there have any way of measuring the impedance of their cables and many believe that a lower than 90 Ohms is preferable because it allows them to sell longer runs. He says that because any deviation from 90 Ohms (higher or lower) is damaging to the data stream, lowering the impedance of the cable doesn't work. Also, an apps engineer at Belden just told me that most cable companies buy their actual wire from suppliers who will customize things like sheath color and dielectric material, and it's possible that many suppliers supply essentially the same cable to multiple audio cable makers.

 

I am sure he is very knowledgeable, but why make such a change in your position based on his statements? I suspect there are other experts who would disagree with him, at least regarding the actual audio effect down chain. I personally can't hear a difference between/among usb cables, but I have certainly not done a lot of testing so I don't claim to have any definitive answer.

Mark

[Paul R]

Mea Culpa, I guess. I just had a nice discussion with Gordon Rankin of Wavelength. Gordon is the man who designed the Ayre QB-9 and the AudioQuest DragonFly DAC, as well as the WaveStream® IsoSynchronous USB protocol. He said a number of things that really took me aback. The first thing he said was that yes, USB cables do sound different. They shouldn't but they do. He says the reason is because most manufacturers are unable or unwilling to make their cables with the correct 90 Ohm impedance and be able to pass up to a 2.6 GHz perfect square wave. He says that unless those two parameters are met, the USB feedback mechanism doesn't work because reflections get the signal confused on the computer end. Without it, there's no way for the computer to know that it's sending the data at the proper rate and bits get dropped. Since USB receivers have no error correction (this was news to me) a dropped bit gets interpolated at the DAC, and distortion increases. He says that this situation is not helped by the fact that Windows, including Win 8, generate 12% more hard errors in a digital audio bitstream than does Apple's OSX! He also says to play your computer audio directly from memory for lowest error rate on either platform, and if possible, keep your music on a Firewire, eSATA or Thunderbolt drive rather than USB.

So, If you want your computer sourced digital audio system to sound it's best, find a cable manufacturer that will guarantee his cable's impedance at 90 Ohms* and that his cable can pass, ideally, a 2.6 GHz, or at least a 0.5 GHz perfect square wave (seems like a pretty high frequency to me), and that your music server runs OSX rather than Windows.

 

*Gordon also told me that virtually NONE of the cable manufacturers out there have any way of measuring the impedance of their cables and many believe that a lower than 90 Ohms is preferable because it allows them to sell longer runs. He says that because any deviation from 90 Ohms (higher or lower) is damaging to the data stream, lowering the impedance of the cable doesn't work. Also, an apps engineer at Belden just told me that most cable companies buy their actual wire from suppliers who will customize things like sheath color and dielectric material, and it's possible that many suppliers supply essentially the same cable to multiple audio cable makers.

 

(grin) Now you see why some folks jumped you when you first came around? I won't say I told you so, but... (grin) Welcome to the "Dang Me!" state of mind again George.

 

Now, it won't be long before someone posts an attempt to totally repudiate everything you just posted... (*sigh*)

 

-Paul

[sbgk]

(grin) Now you see why some folks jumped you when you first came around? I won't say I told you so, but... (grin) Welcome to the "Dang Me!" state of mind again George.

 

Now, it won't be long before someone posts an attempt to totally repudiate everything you just posted... (*sigh*)

 

-Paul

 

thought there were dacs that could check for bit perfectness and haven't found errors. Does seem a bit of a strange claim, we've gone from ground plane noise to errors. 12% errors in win8 streaming, something wrong there.

[gmgraves]

(grin) Now you see why some folks jumped you when you first came around? I won't say I told you so, but... (grin) Welcome to the "Dang Me!" state of mind again George.

 

Now, it won't be long before someone posts an attempt to totally repudiate everything you just posted... (*sigh*)

 

-Paul

 

 

Now you see that when I'm proven wrong, I will own up to it, unlike many who just sulk off the thread only to show up somewhere else spouting the same bullpuckey. This doesn't mean that I'm about to run out and buy a megabuck USB cable. I haven't heard any improvement great enough to make me do that, I'm simply not that neurotic about this stuff.

 

And this new knowledge doesn't let the cable manufacturers off the hook though for making expensive USB cables that are not only wrongly designed, but really aren't designed at all. Looks as if they just grab some 4-conductor shielded wire and solder couple of USB connectors on it and run it up the flag pole with a high price tag and see who salutes it! IOW, "They built it, not know what they built, he sold it, not knowing what he was selling and the audiophile bought it, not knowing what he was buying." What a way to run a railroad! No wonder there is so much skepticism in this hobby.

[kumakuma]

The fact that two knowledgable individuals (Gordon Rankin and John Swenson) have completely different theories as to why different USB cables can sound different is interesting. I am sure we can also find another engineer with a completely different theory if we look hard enough.

 

I do agree with Gordon's statement that Apple's OS X is superior to Windows when it comes to playing audio files.

[sandyk]

I do agree with Gordon's statement that Apple's OS X is superior to Windows when it comes to playing audio files.

As would most Mac users, and the opposite for most Windows users !

Gordon Rankin's view in this area may be at odds with those of Peter St, and possibly Miska ?

[kumakuma]

As would most Mac users, and the opposite for most Windows users !

Gordon Rankin's view in this area may be at odds with those of Peter St, and possibly Miska ?

 

I'm sorry, Sandy Alex, Gordon Rankin said it so it must be correct.

 

Just as Marty Colloms agrees with you about identical files sounding different, therefore he must be right.

 

The point here is that we all have a tendency to pick our favorite experts based on whether or not they agree with our preconceptions.

[kennyb123]

The fact that two knowledgable individuals (Gordon Rankin and John Swenson) have completely different theories as to why different USB cables can sound different is interesting. I am sure we can also find another engineer with a completely different theory if we look hard enough.

 

There's no rule saying that there can be only one answer. Both are coming at it from different directions and it sounds to me like both are onto something.

[Teresa]

The point here is that we all have a tendency to pick our favorite experts based on whether or not they agree with our preconceptions.

 

I would take this as a truism and a human attribute. To me it's logical to trust others opinions when they match or come close to one's own listening experiences. To trust in experts which disagree with one's reality I would see as a mental disorder.

 

However for me, new discoveries of audible attributes and differences while they may be enough to get me to audition a product are not enough to blindly accept its relevance to me. I make NO judgement until it is heard in my room, in my system with my ear/brain system. I alone decide if the musical enjoyment and sonic improvement is worth the additional to cost to me. After all experts and others are not listening to my audio system, I am!

 

BTW I use an inexpensive Belkin USB cable for my Teac DAC, it's possible in the future I may try something better. But because I am happy with my cheap USB cable I would never belittle anyone who is thrilled with something better.

[cvrle59]

So, I just replace my win machine for a mac and I gain automatically 12% in SQ...give me a brake. Internet is great, but it can create so much confusion, so anybody can say anything avoiding any kind of responsibility. Can anybody here point to some validation results to cover this nice story. I will drop my PC right away replacing it with a nice shiny mac, as soon as I see it.

cheers

[Habanero Monk]

Not surprising at all. Same story for ethernet cables.

 

 

Cheers

 

How is it the same with Ethernet cables?

[sandyk]

There's no rule saying that there can be only one answer. Both are coming at it from different directions and it sounds to me like both are onto something.

 

It's all part of a big Jigsaw puzzle, and nobody yet appears to have all the answers. Every little piece of information from different sources may help to complete the puzzle.

[new_media]

So, I just replace my win machine for a mac and I gain automatically 12% in SQ...give me a brake.

 

That's not what he said, nor can I fathom how you would quantitate SQ in such a way.

 

He said Windows makes 12% more errors processing a bitstream compared to a Mac. So if a Mac drops 10 bits per billion, a Windows machine would drop 11 bits per billion.

[k6davis]

Mea Culpa, I guess. I just had a nice discussion with Gordon Rankin of Wavelength. Gordon is the man who designed the Ayre QB-9 and the AudioQuest DragonFly DAC, as well as the WaveStream® IsoSynchronous USB protocol. He said a number of things that really took me aback. The first thing he said was that yes, USB cables do sound different. They shouldn't but they do. He says the reason is because most manufacturers are unable or unwilling to make their cables with the correct 90 Ohm impedance and be able to pass up to a 2.6 GHz perfect square wave. He says that unless those two parameters are met, the USB feedback mechanism doesn't work because reflections get the signal confused on the computer end. Without it, there's no way for the computer to know that it's sending the data at the proper rate and bits get dropped. Since USB receivers have no error correction (this was news to me) a dropped bit gets interpolated at the DAC, and distortion increases. He says that this situation is not helped by the fact that Windows, including Win 8, generate 12% more hard errors in a digital audio bitstream than does Apple's OSX! He also says to play your computer audio directly from memory for lowest error rate on either platform, and if possible, keep your music on a Firewire, eSATA or Thunderbolt drive rather than USB.

So, If you want your computer sourced digital audio system to sound it's best, find a cable manufacturer that will guarantee his cable's impedance at 90 Ohms* and that his cable can pass, ideally, a 2.6 GHz, or at least a 0.5 GHz perfect square wave (seems like a pretty high frequency to me), and that your music server runs OSX rather than Windows.

 

*Gordon also told me that virtually NONE of the cable manufacturers out there have any way of measuring the impedance of their cables and many believe that a lower than 90 Ohms is preferable because it allows them to sell longer runs. He says that because any deviation from 90 Ohms (higher or lower) is damaging to the data stream, lowering the impedance of the cable doesn't work. Also, an apps engineer at Belden just told me that most cable companies buy their actual wire from suppliers who will customize things like sheath color and dielectric material, and it's possible that many suppliers supply essentially the same cable to multiple audio cable makers.

 

Now that you're more open to the idea, if you're so inclined, you could listen to some USB cables.

 

Being a skeptic initially, I dipped my toe in with the $135 Mapleshade Clearlink Plus which I like very much. My experience with USB cables is limited, but I haven't yet heard one (even a more expensive one) that I prefer and that one didn't break the bank. In addition, it has an obviously, visibly unique design, so you can be sure that it's not just some generic cable in a fancy package. Most importantly, I like the way music sounds through it. What impressed me even more, is that after I'd been enjoying it for several months and compared it to a few others, I re-read Mapleshade's webpage about the cable and the improvements they promised (which sounded like good marketing-speak initially) largely matched my favorable impressions.

 

It's very interesting what he said about Windows vs Mac. I moved from Windows 7/8 to Windows Server 2012 and found a noticeable improvement. When I added audioPhil's Optimizer to that, there was a large improvement.

 

What I'm taking away from all of this is that the idea of "bits is bits" is dead and buried, IMO. In a computer audiophile system, the data goes through a multitude of stages before it arrives at our ears. There are all kinds of variables, known and yet unknown, to account for differences between what should seem to be hearing and what we hear. Even worse, it's extremely easy for anyone (experts included) to come to the wrong conclusion about a product/tweak/technique due to the wild disparity in (and rapidly evolving) systems and configurations.

 

So I'm very open to input, especially where there's a consensus, but nothing that any expert can say trumps what I hear with my ears.

[erin]

As would most Mac users, and the opposite for most Windows users !

Gordon Rankin's view in this area may be at odds with those of Peter St, and possibly Miska ?

 

So much fun when the experts eat their own words. There are a few people around here and on other forums saying this stuff for years.

 

Actually I'd like to see some proof of

the fact that Windows, including Win 8, generate 12% more hard errors in a digital audio bitstream than does Apple's OSX!

citation? evidence? test results?

 

Ive yet to hear any Mac that sounds better than a Windows PC . Doesnt mean it is true, just my personal experience.

[k6davis]

How is it the same with Ethernet cables?

 

If you didn't know, there are audiophile Ethernet cables and there's a similar debate over whether they can possibly have any impact on SQ. A reviewer I trust has said that they most certainly do. I intend to give one a try as my next upgrade.

 

I have a JPlay dual-server configuration where the two computers are presently connected via a generic Ethernet cable. That cable is (literally) central to my setup, so I'll be listening for a significant difference. If I don't hear one, the fancy Ethernet cable goes back.

[cvrle59]

So much fun when the experts eat their own words. There are a few people around here and on other forums saying this stuff for years.

 

Actually I'd like to see some proof of citation? evidence? test results?

 

Ive yet to hear any Mac that sounds better than a Windows PC . Doesnt mean it is true, just my personal experience.

+1

[erin]

thought there were dacs that could check for bit perfectness and haven't found errors. Does seem a bit of a strange claim, we've gone from ground plane noise to errors. 12% errors in win8 streaming, something wrong there.

 

 

Can be confirmed or denied quite easily with a loopback test.

[erin]

If you didn't know, there are audiophile Ethernet cables and there's a similar debate over whether they can possibly have any impact on SQ. A reviewer I trust have said that they most certainly do. I intend to give one a try as my next upgrade.

 

I have a JPlay dual-server configuration where the two computers are presently connected via a generic Ethernet cable. That cable is (literally) central to my setup, so I'll be listening for a significant difference. If I don't hear one, the fancy Ethernet cable goes back.

 

I've been there and done that. Yes the ethernet cable made a difference on my system. I just compared pre made cheap multistrand cable vs some solid core install grade cable terminated by myself. It cost me nothing to try. There was a difference. Wasnt huge. But was audible. Do I care? No not really. I dont run a network streaming system anymore. But, If I was going to fork out the big bucks for an "audiophile" "anything" cable I'd want to try it in my own system and have a two week trial with a "no quibbles" fully refundable return policy. Otherwise I wouldnt bother to try it. Simple!

[k6davis]

I've been there and done that. Yes the ethernet cable made a difference on my system. I just compared pre made cheap multistrand cable vs some solid core install grade cable terminated by myself. It cost me nothing to try. There was a difference. Wasnt huge. But was audible. Do I care? No not really. I dont run a network streaming system anymore. But, If I was going to fork out the big bucks for an "audiophile" "anything" cable I'd want to try it in my own system and have a two week trial with a "no quibbles" fully refundable return policy. Otherwise I wouldnt bother to try it. Simple!

 

Audioquest's line of Ethernet cables are all Cat 7 and they range in price from really cheap (if there's a benefit) to "yikes!".

 

I'm going to buy two different models in the upper-middle of the line and depending on what I hear, one or both will go back. Like you said, simple!

 

Thanks for sharing your experience. Now I'm even more looking forward to trying it.

[Teresa]

Now you see that when I'm proven wrong, I will own up to it, unlike many who just sulk off the thread only to show up somewhere else spouting the same bullpuckey.

 

This is one reason I never make definitive absolute statements about what other people are supposed to hear or not to hear, thus it's impossible for me to be wrong as I don't have an opinion. Instead I believe each person should trust their own ear/brain system over a period of time to allow them to really hear what they are auditioning under all possible music conditions. Expects are good for ideas of products to audition and advise on system setup but they are not a substitute for listening.

 

I have been wrong many times in the past and I blame it on short-term listening. I have raved about a new piece of equipment, tweak or treatment to make discs sound better in the first couple of days of use and realized that I was either overoptimistic or totally wrong when the newness wore off and the true sound was evident. I now believe in long-term listening before commenting on anything. I wait until I have lived with something for a month before commenting. For me long term listening is the only thing that works, I cannot say it will also work for others as every person is different.

 

This doesn't mean that I'm about to run out and buy a megabuck USB cable.

 

If you do make sure to get a money-back satisfaction guarantee.

 

I haven't heard any improvement great enough to make me do that, I'm simply not that neurotic about this stuff.

 

For me it is cost, while I have no reason to doubt others enjoy the improved sound I must live on a budget and it has to be a good bang for the buck. I am happy with the sound of my Teac DAC with a cheap Belkin USB cable, however that doesn't mean I won't try something better in the future.

[erin]

Well according to this organisation, there are plenty of USB cables that meet the 90 ohm specification.

USB.org - USB-IF Compliance Program

 

Seems like you just need to find a cable that has passed the compliance testing.