Ever since I was young, there has been this mystery. Intermittent digital noise, that one day appeared as if from nowhere. For the entirety of my music making years, I have been asking myself: Why one day, did my digital audio go from being immaculately clean, clear and reliable, to noisy, harsh and unreliable? I tried so many different pieces of gear and different ways to set it up. Yet the obvious illuded me. The answer the whole time was USB audio can be total garbage. THAT was why when I switched back to optical audio, all my noise issues went away. It doesn't even seem to make sense why one USB device will have processor noise pollution and another wont. Example: http://www.sndup.net/dc2c8

So, if anyone tells you USB audio is clean and reliable, don't be so sure.

That recording is processor noise perpetuating through my USB audio. Every computer I have EVER owned, from cheap walmart notebooks, to massively expensive professional towers, have had this issue when using USB for audio. Almost EVERY DAC I've EVER owned, from cheap chinese junk, to massively expensive "end game" gear, have had this issue when using USB for audio. Why 1 or 2 of them didn't have this problem is a mystery to me.

This type of digital noise is mostly reactive. When ever you move your mouse, open a window, run a program or do ANYTHING actively on a computer, this noise is created in the background and pollutes EVERYTHING connected via USB. From what I can tell, it is a common design flaw with a lot of USB devices. No filters or repeaters I've ever tried, got rid of it. The only cure was to either find the rare USB device that magically doesn't have this issue or go optical.