USB to External Hardrive does USB cable matter?

It should not matter since music on hard drive has no timing but I bet you'll find somebody claiming big sonic difference.

I second Kijanki's comments, especially given that the USB cable is a long distance away from the audio system, which most likely eliminates the possibility that rfi could radiate from the cable into the system.

If your ethernet cable is the unshielded type, though, it MIGHT be worthwhile replacing it with a shielded ethernet cable, to prevent radiation of rfi from it into the system. See BryonCunningham's recent thread. There is a lot of unrelated discussion in that thread, but you can use your browser's "find" function to quickly find the posts that mention "ethernet."

Very conceivably Bryon's findings were system and setup specific, and might not be applicable to your system. But ethernet cables are cheap, so it might be worthwhile trying that if your present ethernet cable is unshielded. If the body of the plugs on the cable are plastic rather than metal, the cable is unshielded. Some additional guidelines on how to tell whether the cable is shielded or unshielded are discussed in the thread.

Regards,
-- Al

I second Kijanki 100%.