USB Audio - what you need to know

A brief, layman's explanation about why USB cables could actually make a difference to the sound from your computer and DAC.

[TWEAKER]

Lachlan, much of your reasoning given for signal jitter is correct, but it's also why
a) asynchronous USB receivers generally feature isolation transformers (in the DAC), and
b) the DAC re-clocks the signal - entirely.

The DAC doesn't simply output what it receives.

So if a USB cable is made properly, without connection faults and with adequate shielding against RFI and EMI (and gold or silver plated connections to prevent oxidation at the connectors), the digital signal will get through unscathed. Or something is faulty in the DAC. - audio engineer.

[squidcaps]

Horrific amounts of misinformation is found in this video.

DAC reads "voltages" considerably higher rate than thousands, you are off by a factor of a thousand.

Even if we would somehow able to transfer the changes in voltages on the USB signal we have another problem: the data arrives to a chip. That reads it and says to the next component " this is a zero" or "this is a one". The next component is memory that stores the one/zero in to a flip flop gate. From there we get a DATA request to retrieve the value we stored as zeros and ones in the memory. That is then given to the next piece, the actual DAC. This is of course dumbed down version but all USB DACs use this general scheme. There is nothing "analog" that can go thru all those gates as it is then data. If this is somehow not understood, i suggest looking at how logic circuits work.

For USB power, same requirements are there as are with any pre-amplifier or line level device. It is true that USB power can in rare cases cause audible noise. This has NOTHING to do with the cable. The first components the USB power sees at each end of the cable are literally MILLIONS of times stronger on defeating noise than USB cable can even theoretically do, we can enter superconductors in that equation and still you would be several solar systems off (well, maybe i'll tone it down and say just the moon and earth in distance is comparable to a car trip when it comes to USB cables and what is at both ends of that cable....). If you have USB noise, we have cures for those and those are the same cure as anything to do with power noise: isolation and filtering: converting electronic signal with induction to magnetic, thru airgap and boom: no electronic connection exists anymore but electricity goes thru unchanged.. That magical device is called isolation transformer. Digital signal has not been a problem since the days of DMX, triode dimmers and unbalanced lines.

Source: actual audio engineer, that include both software and hardware, not a freaking wannabe. There are no known theories to support claim on digital cable "audibility" that have any research backing on it, it fights against the design principles of the gear (do you guys really think that no one has thought this before? before USB was even a glimpse? ). The solutions are so cheap that it is ridiculous. Even if the cable believers theories are true, 5 cent worth of components cure those problems literally millions times better than cables can do. Same ratios goes to all analog signals, cables are meant to be non-existent in the chain and electronically, they are as close as a component can be. There is still thousands of feets of wire between you and the source, before we get to the USB part...

[Tacet]

Well as a IT specialist and software engineer i must say i have never ever heard such missinformations and misunderstaniding.