USB cable hype

"My OP asked about need not preference for expensive USB cables. This could have been posted more clearly. Need is about functionality."

"Having said that, what is good enough? Is it the cable that costs another $50 or $500? I think the cable industry intentionally does us a disservice of keeping us in the dark in order to sell into that ignorance."

If you're just concerned about the function of USB, and things like maximum cable lengths before the signal starts to degrade, there really isn't any industry conspiracy. USB specs are published like any other format. Now if a private company wants to go out and make high end, expensive USB cables, who's to stop them? And why would someone stop them? (I'm assuming the people making these high end cables are not breaking any laws, such as copyright infringement, or similar type of offense.). So, as long as you stick to whatever standards the format requires, you shouldn't have any problems from a functionality standpoint, regardless of cost. Even a cheap cable should be fine. I found this website for you to look at. Its a business that sells cables, but they go over the requirements for the different versions of USB cables (USB 1, USB 2, USB 3, etc...)

http://www.yourcablestore.com/USB-Cable-Length-Limitations-And-How-To-Break-Them_ep_42-1.html

Thanks Sd542. I was originally thinking functionality only because bit errors should be zero in the audio range. But digging deeper, I realize that may not be true. Some USB cables may result in fewer errors than others. In which case, it's not only about functionality but also about SQ.

Cable manufactures aren't doing anything illegal. But I would call it unethical to mislead the customer for profit.

Hi Kijanki, I agree with everything you said except for this one thing: "...jitter does not even apply here".

Just because the source clock isn't used inside the DAC doesn't mean that it has no effect. The DAC clocks data only after it reaches the DAC. The source clocks data up to that point. Source clock jitter combined with cable jitter may err a bit before it reaches the DAC.

For short cable runs, bit errors induced by the cable are unlikely. For long cable runs, bit errors are inevitable. Therefore, the longer the cable and more marginal the source, the more the cable matters for both function and SQ.

Of course, as you mention, a cable may also help SQ by isolating the signal from various noises.

Here is a link showing a good USB eye vs bad eye.

http://www.embeddedstar.com/weblog/2009/06/07/industrial-usb/

Here is a USB chip vendor's failing eye diagram.

http://e2e.ti.com/support/arm/sitara_arm/f/791/p/283089/987150

One eye is open. The other two eyes are closed without a long cable. The good eye doesn't need any help. Any cable will do. The bad eyes need all the help they can get. The cable is critical. Reality is that you aren't searching for that magic touch (whatever that means). You are searching for the cable that does the least harm. Silver will 'sound' better because it is faster. But silver won't sound any better for the open eye.

I have two extra pair of Wireworld Starlight and one Pangea AG USB cable. I cannot tell the difference between these and the basic monoprice cables except that the more expensive ones seem more sturdy. Sound-wise, not a whit of difference. I wish I were able to so I didn't feel dumb spending money for what is basically a give away item.