I don't know where to begin. There's basically nothing in this post that's correct.
There is no storage inside the OPPO you can use to "download" songs. The only drive in the OPPO is the shiny disc (optical) drive. Files played from USB-attached, external hard drives play at IDENTICAL quality to the same files played off of shiny disc, so if your WAV rips aren't sounding identical to the CDs you ripped from, then there is something wrong with the way you did the ripping.
Yes I got confused with comments made about deleting files from "playlists" thinking that meant the 105 could store songs. Thanks for clarifying for me. I have to do more tests to see if there is a difference in quality. If everything is going through same circuitry, there shouldn't be any.