Schiit does a bunch of power filtering, as StanD mentioned above. It's possible, if you have a very noisy source, that you might get some noise. If that turns out to be the case, you should be able to fix it by plugging it into a powered hub or different USB port in most cases. I suspect most people have no problem with USB (I know I don't), but there will always be a few that do. Easiest thing to do is just try it out, there's a good chance it will be just fine.