2 digital CD ripped music sources with identical WAV. music on each. 1: Gateway Win 10 lap-top with a SanDisk 960 Gig SSD USB fed to a Peachtree X1 USB to S/PDIF coax converter. 2: OPPO UDP-203 using either a SSD to USB converter with as high capacity as 2 Tb Corsair SSD, or a 500 Gig flash drive, S/PDIF coax output connected. Both ripped music sources S/PDIF connected to a S/PDIF coax 4X1 selector switch which outputs to my Grace Audio M920 DAC and a 1X5 S/PDIF coax splitter so I have a S/PDIF feed to my Living room`s Integra A/V/P selectable S/PDIF input for background music while the Living room`s tube amplifier system settles in ,before selecting and playing a BR DVD/CD, etc. when I have guests over. After the DAC`s conversion to analog it`s sent to my Mac. C 37 preamp, which solely used for 6 room analog audio signal selection & then on to feeding my audio distribution matrix. All WAV. music files are backed up on 2 other SSD lap-tops + multiple internal connected, and disconnected SSD`s & non connected flash drives for music file backup safety. Very versatile & file redundant, IMHO. for my needs.