I have an Oppo 95 with a 2TB Hitachi 3.5" eSATA HDD in a SATA Thermaltake enclosure as my music files storage. I swapped it with a 500GB Seagate 2.5" eSATA HDD in the same SATA Thermaltake enclosure. After listening a few songs, I thought they sound different. So I searched on line for "do hard drives with music sound different". I found this http://www.computeraudiophile.com/f7-disk-storage-music-library-storage/hard-drives-make-difference-sound-18190/ There is a comment there that said the Seagate has a "relaxed" sound compared to Hitachi which is what I was hearing. I guess you can do your own experiment.