I've tried many ways to 'purify' the usb data. Regen, Curious cable, Intona, Wireworld platium etc... Some of them worked, but heavily reduced the dynamic. (I guess high dynamic is sort of 'fluctuation' that are filtered.) Some of them just don't work at all. It bothered me a lot, until I thought that only light may be naturally free of noise with no other solutions... Yes, I switched to SPDIF. The most expensive one on Amazon is just $20. Hundred times less than what I've spent. I can't be happier with the sound, bass is fuller, background is darker, oh it's not dark, it's vancuumed emptiness of nothing. I know some sayings like SPDIF combines clock and data info all together blah blah. I think DAC nowadays can perfectly handle it. (by listening to it, more than reading about it.) With SPDIF, the sound is exactly what it meant to be. Say nearly 100% transfer rate, where usb is at most at 60%. Thanks god that cable manufacturers never tried to produce an hifi SPDIF cable (or I can't prevent myself from buying one as I was scared by the cheap price tag). Maybe they just can't, light is naturally transferred at highest performance. You can't make light transfer 'better'.