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Who has tried out different USB Cables?


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18 minutes ago, sandyk said:

 

I have NEVER made a request for OP privileges in any threads that I have started.

My question above is completely valid too,. but is also likely to be removed .

 We need to find out WHY various USB cables can sound different without them altering the received Binary Data.

Removal of posts should only be used when the posts are a deliberate attempt to derail a thread, not to prevent genuine discussion.

Comparing digital audio USB cables is like comparing sewer systems, they’re all sh_tty, so who cares which is best? I suspect that if, indeed, USB cables alter the sound when the received data is unaltered, then either different cables “smear” that data enough to cause audible errors, or, it’s another case of listener bias.

George

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20 hours ago, Ralf11 said:

Let's stick to experiences with USB cables, mechanisms as to why they could degrade SQ, and whether a different interface may offer better SQ.

 

 

Can't speak as to mechanisms,  but my chain of improving asynch USB adapters over time was

 

HiFace

John Kenny MKIII

iFi Nano

Gustard U12

Schiit Eitr

 

I've always found coax/toslink direct from source to be disappointing vs asynch USB, with the caveat that my budget doesn't encourage auditioning

source gear over $2k

Regards,

Dave

 

Audio system

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3 hours ago, Superdad said:

 

You do know that what travels on a USB is not "ones" and "zeros" data, right?  It is very high-frequency "analog" DC voltage, and inside that "noise," every 125 microSeconds comes a modulated packet in which the data is encoded.  Then, in every USB input--be it a printer or a DAC--is a PHY chip (these days integrated in the USB MAC processors, but its function is there nonetheless) whose job it is to determine what in that bursty/noisy high-speed signal is a "one" or a "zero."  

Study the function of a PHY for a bit (@JohnSwenson has actually designed PHY chips) and you will see they are filled with PLLs, clocking at various phases, and funky gain circuits to allow them to decode some rather piss-poor signals.  The harder the PHY chip has to work, the more noise (from bursty current demand) it puts on the ground plane--inside the DAC. And this is measurable inside the DAC.

 

This brings us back to the reason USB cables can "sound" different (as well as the raison d'être of our REGENs): Impedance match and signal integrity. This is measured on an eye-pattern, which will show amplitude, slew, noise, and jitter.  

And while yes, anything within the USB spec will allow the PHY to do its job, for audio it is bit like with other measurements.  That is, the measurement folks will say that below a certain threshold we can not hear differences of distortion, jitter, slew rate, transients, etc.--yet people hear plenty of differences, some of which probably have no correlation to present measurements.  So I don't care how good someone is at interpreting an eye pattern: it's just proving there are differences between the cables or the signal--it can not be used to characterize what will be heard.

 

So George, I question you when you say "All USB audio is equally poor"--while at the same time saying that all USB cables sound the same--because it demonstrates either your lack of technical understanding or a lack or curiosity. :/

Yes, I know how it works. I also know that the bus was developed to connect keyboards and mice to computers. It’s relatively slow, was designed with interrupt protocols to facilitate bus sharing and was designed so that the computer, not the peripheral controls arbitration and priority. Not exactly ideal for transferring audio from computer to DAC.

George

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15 hours ago, gmgraves said:

Yes, I know how it works. I also know that the bus was developed to connect keyboards and mice to computers. It’s relatively slow, was designed with interrupt protocols to facilitate bus sharing and was designed so that the computer, not the peripheral controls arbitration and priority. Not exactly ideal for transferring audio from computer to DAC.

It was an evolution of RS-232 to RS-485 to USB, it is a standard serial interface, that was not only designed to fasten keyboards and mice to PC's. but also provide a new standard serial interface....

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On 10/13/2019 at 12:29 PM, Superdad said:

 

You do know that what travels on a USB is not "ones" and "zeros" data, right?  It is very high-frequency "analog" DC voltage, and inside that "noise," every 125 microSeconds comes a modulated packet in which the data is encoded.  Then, in every USB input--be it a printer or a DAC--is a PHY chip (these days integrated in the USB MAC processors, but its function is there nonetheless) whose job it is to determine what in that bursty/noisy high-speed signal is a "one" or a "zero."  

Study the function of a PHY for a bit (@JohnSwenson has actually designed PHY chips) and you will see they are filled with PLLs, clocking at various phases, and funky gain circuits to allow them to decode some rather piss-poor signals.  The harder the PHY chip has to work, the more noise (from bursty current demand) it puts on the ground plane--inside the DAC. And this is measurable inside the DAC.

 

This brings us back to the reason USB cables can "sound" different (as well as the raison d'être of our REGENs): Impedance match and signal integrity. This is measured on an eye-pattern, which will show amplitude, slew, noise, and jitter.  

And while yes, anything within the USB spec will allow the PHY to do its job, for audio it is bit like with other measurements.  That is, the measurement folks will say that below a certain threshold we can not hear differences of distortion, jitter, slew rate, transients, etc.--yet people hear plenty of differences, some of which probably have no correlation to present measurements.  So I don't care how good someone is at interpreting an eye pattern: it's just proving there are differences between the cables or the signal--it can not be used to characterize what will be heard.

 

So George, I question you when you say "All USB audio is equally poor"--while at the same time saying that all USB cables sound the same--because it demonstrates either your lack of technical understanding or a lack or curiosity. :/

 

Thank you... thank you... thank you...!

 

I have had so many similar discussions On circuitry that’s involved and that it’s not so simple as just 1’s and 0’s. It takes careful design of electronics and good cable to reduce electrical noise that will leak into the dac and it’s analogue amp and that there is no perfect isolation.

 

 

 

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As to the question on why someone would use USB at all compared to Ethernet/WiFi the answer depends on what one is doing with their system. At this stage there are no Eth/Wifi solutions that work well or at all for room correction purposes so this leaves USB and then only a few USB implementations can do multiple channels in a Bi-Directional manor. I would prefer hard wired Ethernet if the option was there but at this point its not so USB it is, for me.

 

At the end of the day any SQ differences between ETH/USB/Wireless are so small in the grand scheme of other things that bring real value add to ones listening that its almost not worth discussing USB cables at all. Let's not forget also the loss of hearing that goes along with the long term effects of the audiophile hobby in general. Unless your listening to your system at 65db all the time (why bother) any SQ changes between the various interfaces/cables will be wiped out easily by a months worth of 90db plus jam sessions....where the real fun begins. I myself prefer 105db or so. You gotta feel it to get a sense of "Being there"..IMO :)

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13 minutes ago, barrows said:

@marce, I expect that kind of snarky comment from @mansr, but not you.  Of course DC is DC, but one of the issues with the USB output of, say, an ordinary consumer computer is that the USB power lines actually do have an AC (noise) component on them (noise, in other words).  This noise is easily measurable (easy enough so as not to need a spectrum analyzer to see it).  This is one of the reasons Audiophiles can get better performance by using a component with a purposely (for audio) deigned USB output which reduces the noise on the 0 VDC and 5+VDC lines.

Superdad "clarified" that he was referring to the data rate. Tell, me what is the Vbus data rate?

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