[The Pell]

I just want to see someone do something about it (And post it in the correct place).

 

[vandaven]

Quote:

Just because you have a spec doesn't mean it can't be improved upon. A automobile has a certain spec. An engine or power source,some way to control it and a way for it to move under it's own power,etc,etc. So why does Ferrari or Porsche or Aston Martin bother making any changes to that spec? Why try to improve on a Yugo? Surely a Yugo is an automobile just like an Aston Martin is. But I would like to drive the Aston Martin because they improve on the spec,by using superior materials and build quality. But hey that's just me. To each his own. I'm not going to hate on you for driving your Yugo

Please leave completely different (analog) technology like cars (with internal combustion engines) out of this discussion, it doesn't match the topic.
 
USB technology is not even equal to "clocked" digital signals like S/PDiF or AES/EBU as it is just a stream of data that is turned into a time discrete digital or analog signal via the DAC inside your USB interface. 
 
 
 
 

 

[svyr]

heh we could get it moved to the sound sci forum

 

[00940]

 
Quote:

First off, this is a very entertaining thread. 
 
As we all know, in most cases, the USB controller of the computer is not directly inside the USB port.
 
Let's say that inside my "standard" PC, there are a couple of flimsy wires connecting the USB ports to the motherboard, will an expensive "audiophile" USB cable make up for these (which might degrade my USB sound before it actually reaches the port)?
(same could be asked in regards to AC cables and poor AC cabling in the house)
 
Are there certain desktop computers / laptops / motherboards etc. that are more "audiophile" than others? 
 
Why would a high-priced "audiophile" USB cable only affect expensive audio systems? If the cable really makes a difference, it would affect the sound of any USB sound device, wouldn't it?
 
 
 

Some good questions here regarding computers:
 
- there are desktop computers or laptops with widely different performances and it's almost impossible to know which are the better ones without doing some tests. Some factors:
 
* The quality of the computer power supply. It's not a question of power but of how clean it is. A noisy PS can either directly inject LF noise into devices attached to it (so did my previous compaq laptop) or higher frequency noise can affect the proper operation of the USB controllers or of the IC inside an attached device (as mentionned earlier, Paul Miller was able to measure jitter on a USB audio connection jumping from 300 ps to 3ns depending on whether or not the laptop was operated on battery or switchmode PS).
* The quality of the USB controllers and chips surrounding them. Not all parts are created equal, some simply have better performance. Clock generators and the like range from very good to quite poor.
* The hardware implementation of the USB controllers. Depending on pcb layout, decoupling and so on, they'll be more or less vulnerable to unwanted interaction.
* The structure of the motherboard, the code attached to it, the OS, the software layer... For exemple, depending on the priority granted to USB processes by your system, you can have data drop out.
 
Funny thing is, you could have ports on the same computer with various levels of performances. Still, considering all the potential things that can go wrong, it is extremely likely that the problems coming from the computer itself are much bigger than any problems a cable could induce in USB audio transfers. On the other hand, there is also little a cable could do to fix those problems.
 
- The effects through which cables can in theory make a difference (mostly jitter and power supply corruption) are quite small. Admitting for a moment that they are audible, the distortion they would induce would probably be drowned in the self produced distortions of a cheap device.
 
 
Quote:

USB technology is not even equal to "clocked" digital signals like S/PDiF or AES/EBU as it is just a stream of data that is turned into a time discrete digital or analog signal via the DAC inside your USB interface. 
 

While not "equal" to spdif, the most common USB audio transfer protocol (adaptive) shares the same fundamental problem of recovering the system clock from a data stream. It is not by chance that TI used the same SPACT audio clock recovery system for both USB and spdif receivers.

 

[Prog Rock Man]

Quote:

If you have never tried an audiophile grade USB cable in your system and would rather just say that it makes no difference because you like to spit out digital specs and hyperbole. Please please Shut-up! You do not have the right to speak. If you have tried a superior grade USB cable and found it to be no better than your Walmart cable, by all means continue.

I bought an Oehlbach USB with super dooper claims and a ferrite core. No matter how much I listened I could not make out a difference between it and another stock cable that came with a printer or whatever.
 
You do have the right to speak if you have knowledge of exactly how USB cables can/cannot affect sound. You have the right to ask questions about the same and put forward your own theory. Don't try and supress knowledge and discussion. It is bad enough blind testing is banned to Sound Science.
 
 

 

[Prog Rock Man]

Quote:

I suggest you search with google for blind test's.
Also cable manufacturers cannot be sued as they are very careful about what they say; they never say that they are better than another cable and they also say things like "Clear and open highs, elegant midrange textures" which could apply to any usb cable as you would struggle to produce unclear highs or untextured mids.
 

True, they are allowed 'puffery'. Russ Andrews and Kimber Kable fell foul of the Advertising Standards Agency when they did make a measureable claim about RFI rejection of their cables. The ASA pointed out that they could not show a connection between RFI rejection and improved sound quality, they could only insinuate such. Smaller bespoke cable makers need to be careful what they say as the costs of an ASA fine and associated legal expenses could cripple them, and the big ones such as Belden are too canny to make any claims they can be held to account for.
 
This is what Kimber say about their USB cable
 
"The popular USB interface now plays an important role in both consumer and professional audio and video. Audio devices that utilize USB data modes require reliable transfer of data to operate properly. To address this need Kimber Kable created high performance USB type cables. Our Mini BUS and B BUS cables utilize copper conductors with an unusually thick (6.1%) silver plating to enhance conductivity and signal support. The largest gauge conductors possible under USB specification are used for both the signal and power conductors. A high performance nitrogen-infused polyethylene (PE) dielectric is used on the signal conductors to maximize signal integrity. Ferrite noise reduction beads are used on both ends of the cable to prevent interference of the delicate data stream. The Mini BUS is terminated with a USB A type connector on one end and a mini B type connector on the other. The B BUS is terminated with a USB A type connector on one end to a USB B type connector on the opposite end."
 
A bit of puffery with 'high performance', 'unusually thick', 'maximise signal integrity' and 'delicate data stream' and nothing measureable or testable. I wonder why????

 

 

[DaBomb77766]

Quote:

I bought an Oehlbach USB with super dooper claims and a ferrite core. No matter how much I listened I could not make out a difference between it and another stock cable that came with a printer or whatever.
 
You do have the right to speak if you have knowledge of exactly how USB cables can/cannot affect sound. You have the right to ask questions about the same and put forward your own theory. Don't try and supress knowledge and discussion. It is bad enough blind testing is banned to Sound Science.
 
 

I have a whole bunch of USB cables with a ferrite core!  I've heard that ones with ferrite cores can actually help with various issues the Fiio E7's DAC sometimes has.  Forgot exactly what these are though.  I've never been very clear over exactly what ferrite cores even do, Wikipedia wasn't awfully helpful on this for me.

 

[Prog Rock Man]

I got one with a ferrite core as I had noticed most of the wires for my laptops and printers have cores on their power and other cables. I figured that if Dell, Sony and HP feel they are of use then they must be. Otherwise why go to the expense?
 
My stock USB does not have a ferrite core and again, it sounds no different to the Oehlbach, which now lives in a bag with other cables, in case I need one that long with the mini B connection it has at one end.

 

[DaBomb77766]

Quote:

I got one with a ferrite core as I had noticed most of the wires for my laptops and printers have cores on their power and other cables. I figured that if Dell, Sony and HP feel they are of use then they must be. Otherwise why go to the expense?
 
My stock USB does not have a ferrite core and again, it sounds no different to the Oehlbach, which now lives in a bag with other cables, in case I need one that long with the mini B connection it has at one end.

It would be pretty silly to use an audiophile cable for, say, connecting your camera to your computer though, since I highly doubt they're as durable as a good stock one.  Not to mention they look kind of really out of place next to all of the other cables.  They look like something that should be inside the computer, not outside.

 

[00940]

Quote:

I have a whole bunch of USB cables with a ferrite core!  I've heard that ones with ferrite cores can actually help with various issues the Fiio E7's DAC sometimes has.  Forgot exactly what these are though.  I've never been very clear over exactly what ferrite cores even do, Wikipedia wasn't awfully helpful on this for me.

To put it simply, the ferrite bead increases the impedance of the transmission line at high frequencies. It thus reduces the amplitudes of higher frequency noise. Think of it as a filter.
 
What is unclear in this wikipedia entry ? http://en.wikipedia.org/wiki/Ferrite_bead

 

[DaBomb77766]

Quote:

To put it simply, the ferrite bead increases the impedance of the transmission line at high frequencies. It thus reduces the amplitudes of higher frequency noise. Think of it as a filter.
 
What is unclear in this wikipedia entry ? http://en.wikipedia.org/wiki/Ferrite_bead

http://en.wikipedia.org/wiki/Ferrite_core
 
Oh, I was looking at that article there.  A little more ambiguous, but I guess it's a totally different thing in that case.  Thanks though, I didn't see that other article.
 

 

[pompon]

Just using USB HUB (with power supply) near your dac.
 
The data coming from the computer is completely restored inside the hub and the noisy current from the computer is not used at all.
 
 

 

[vandaven]

Even though it might seem inappropriate, I just add the results of my little experiment to this thread, if somebody wants to start a new one or move this thread, please go ahead.
 
I decided to buy a usb cable for the test that sells for about 50 € (70 US$), which seems to be the better of the two "budget" solutions that a notorious cable manufacturer offers.
According to a review in a german hifi webzine, that range of usb cables give the listener an improved listening experience that scales with the price. Thus, I supposed the product, while not in the 500 - 2500+ US$ range, should at least give some minimal sound improvement in comparison to a obviously super-cheap, thin, no-name USB printer cable (let's call it "grey") that is at least twice the length of the quality cable. At least the quality cable is red (let's call it "red" from now on) and looks like a quality cable to me. 
 
Back at studio, I connected the "red" to my Digidesign Mbox2, which is a USB audio interface that might not live up to my highest sonic expectations anymore, but it was quite helpful for portable Pro Tools edit work in the past. The plan was to send a 48 kHz 24 bit sound file out of Logic Pro (audio software) to the interface, send it out via S/PDIF, re-record it in Logic via S/PDIF in, and repeat the same procedure with the "grey" cable. Phase-inverting one of the two recordings and summing it up with the other should display the sound differences between the way those two cables transport the audio data, as the only (audible) signal left after this process should be the improved quality "red" adds to the sound.
 
To put a long story short, I was able to achieve a full phase cancellation between the "grey" and "red" signal, even *normalizing* the (presumably empty) audio files did not lead to any noticeable result. Pure fact: "Red" is in no way superior to "grey", but looks a lot better, so it might be worth the extra money. Even though "red" is not the most expensive USB cable on the market, it is believed to improve the sound quality, but alas it doesn't. People who spent thousands on a single USB cable will still insist on the improvement in listening quality.
 
I guess it's nice to believe in magic.
 
 
 

 

[jackmccabe]

This thread really should have been put in the sound science forum, as we cannot discuss that which cannot be named (hint begins with "b" and ends with "lind tests")

 

[00940]

Not sure I understand your chain for the test ? Does the signal ever leave the digital domain ? 
 
Theoretically, I wouldn't expect differences without involving a DAC in the chain (and thus an ADC).