The Omega has 6 analog inputs and 2 S/PDIF inputs, but there are only 4 inputs (pathways) to the computer over USB, so you must select from your physical inputs which you want to go to your computer. You can route the 6 analog inputs to any of the 4 inputs unless you are using S/PDIF input, in which case you'd have to route the analog signals to inputs 3-4 (because S/PDIF must go to inputs 1-2 and must be the only signal going to 1-2).