Originally Posted by Currawong
My thoughts are when the OP's question comes up is: What DAC are you using? Does the USB input use bus power or not? If it does, why not spend money on a USB power solution instead?
I think in the case where the DAC runs off of USB power and you are using a USB cable that meets the standard, and if there is a problem with the DAC having a problem drawing enough power through the USB cable---the precisely because the USB cable is within spec, one should conclude that they have a very poorly designed (or malfunctioning) DAC.
In a situation like this, rather than spend the $456.75 on a fancy USB cable for a marginal improvement in cable resistance (and I'm being optimistic) to mask the symptoms of a poorly made DAC, one could invest that $450 in getting a much better DAC. The Bifrost comes to mind as an example of a $450 USB DAC that has asynchronous functionality, and a power supply that is separate from USB power.
Nevertheless, I think your suggestion of getting a USB power solution is definitely preferable to trying an expensive USB cable.
Originally Posted by Hi Rez
I so wish it were true that async DACs wouldn't benefit from aftermarket cables. Before I tried it, I too thought there wouldn't be an effect. So the quotes need to stay.
Just curious, have you actually tried any comparisons yourself?
I have a USB-powered DAC---a Schiit Modi. I had problems with "glitchiness" or dropouts or whatever it was. So I had to figure out what was degrading the audio. So I have firsthand experience with sketchy DAC performance. Want to guess what the problem was?
Warning: Spoiler! (Click to show)
It wasn't the USB cable.
It wasn't the DAC.
It was the first-generation USB 3.0 ports on my laptop---they weren't playing nicely with the DAC.
I've since used the Modi on native USB 2 ports on several machines--including my laptop's USB 2 ports---with whatever spare USB cables I have, depending on whether I'm at home, in the office, or in the lab, and I haven't had a hiccup since. The USB cables I've used have all been spare cables that came with various USB devices (harddisks mostly).
When trying to debug a situation like this, it's really helpful to have a fundamental understanding of the underlying processes, that way fixing the problem doesn't end up becoming a witch hunt. The USB cable has to do two things for Modi--- transfer the 1's and 0's and transfer the bus power from the computer. The USB cable I was using was in good known working condition from it's performance with other USB peripherals---therefore, I could deduce that the cable wasn't causing the glitches and I could investigate whether the defect was in the computer or in the DAC.
I plugged the DAC into the USB 2 port on the other side of my machine and it fixed the problem---I got a huge increase in the quality of the music! Why? Because I finally got the system hooked up in a way where all the components were operating within spec. My USB3 ports have been buggy and hit-or-miss with other perhipherals in the past, so I had a good idea that the problem was with the computer.
The moral of the story is make sure your components all function within specification. if the cable gets the data from A to B and the power from A to B and is within the specifications, then you have maximized the cable component of the sound system. If there is still a deficiency in the performance of the system, it's because of a different component.
Have you ever checked to see gravity acts differently on the other side of the world? How do you know that people in the southern hemisphere don't see everything upside-down compared to folks in the north hemisphere? The reason you don't have to verify that yourself is because you understand how gravity pulls things toward the center of the earth.
Have you ever checked the performance of the magnets in your headphone drives to see if they operate differently if you are near the north or south pole, or i you are near the equator? Unless you think magnets are miracles, then you realize that the earth's magnetic field is irrelevant.
It's the same thing with state machines, serial communication, digital signal processing, and electricity and magnetism. If you understand the principles, you can save your self the time and hassle of needing to try absurdly over-specified cable that cannot possibly transfer digital information "better" than any other sufficiently constructed cable.
Even if a first-principles approach isn't your forte, inverlose has pointed out the emperical evidence that USB cables can't have anything more than a vanishingly small effect on the DACs performance (quatified to be at least as small as -140dB which is far below any sort of auditory threshold you could concieve).
To quote another headfier (i can't seem to find the post to link to) I experience the sun rise every morning, move across the sky, and set every night. Also, I don't experience any sensation of motion. Therefore, can I conclude that the sun orbits around me once every 24 hours?