Who has tried out different USB Cables?

[xyzzy1]

Feeding a project dac s2+ from a MacBook pro.

 

Tried generic USB cable vs Pangea USB cables, heard differences in amount of edge/harshness in the sound with the Pangea cables being the better, but not by much. Switched to a linear power supply for the dac s2+, that made a pretty big improvement in sound clarity and reduced edge/harness further.

 

Then tried optical cable as the MacBook has optical out in the headphone jack and heard a huge improvement in sound quality with much reduced to almost eliminated edge/harshness and nice added liquidity/naturalness to sound of voice and instruments. No way I'm going back to any USB cable. Strongly recommend moving to optical cable if your setup allows it.

[xyzzy1]

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.

 

 

 

[xyzzy1]

On 11/2/2019 at 2:26 PM, daverich4 said:

No, I didn’t ignore that passage. My only choice to try a cable is to buy it. 

no it’s not. Please use this thing called the internet to look up dealers. Thecableco.com does loaners and Audioadvisor.com offers 30 day return just to name a couple.