Does the Quality of the USB cable matter?

Anyone tried various Cat 5, Cat 6, or Cat 7 Ethernet cables? I use these: a 50 foot cable between my WHS Server and a 1 gigabyte Ethernet switch and then a 5 foot Ethernet cable from the switch to my PS Audio PWD. I've tried all 3 cables in this setup. I thought there was a considerable difference between the 5 and 6 that being: a more musical fuller sound with the 6. When I substituted the 7 the background became blacker and quieter. I would not say these differences are extreme especially between the 6 and 7 but they were discernible and make my system just a little bit better and closer to the real thing for not a whole lot of $$$s.