The 203 is no different than the 103 in this respect, as indicated by their back panels. The feature they lack, and that the 105 and 205 have, is the asynchronous USB DAC input. With all four of the players - 103/203/105/205 - you can play music files via USB by plugging a USB hard drive or USB stick into one of the USB ports. Of course the music will be using the DAC in the Oppo machine. But used this way, the Oppo is controlling everything: You can - and have to - use the Oppo's control interface to find the music and play it. You also have to depend on the Oppo's somewhat limited abilities when it comes to gapless playback. On the 105 and 205 machines, however, you also get a USB DAC input. This input makes the Oppo machine into an outboard DAC. You can't plug a hard drive or stick into this USB port. Instead, you plug in a computer, a dedicated streamer, or some other "smart" device into the port, and that device becomes your user interface. The Oppo just becomes a DAC - the volume control on the Oppo is pretty much the only separate function that remains active in that mode. This mode allows you more choice in the software and user interface you use to catalogue, select, and play your digital music collection. It also allows much better support for gapless playback, since all the work to make that happen is taken away from the Oppo in this mode. Now, the 103 and 203 do have ways to be used as outboard DACs. You can plug into their optical and coax digital inputs, and also into their HDMI inputs. (And the 105/205 also have these same options.) It's just that there are some limitations with those other input methods, especially optical (doesn't always support super high-res data transmission) and HDMI (limited number of external smart players/devices that have HDMI outputs). But the 103 and 203 are identical to each other as far as the ways you can, and cannot, connect to and use them.