I would consider my Lynx Aroura and Apollo to the "hub" of my setup. Obviously nothing would work without my computer, but the DA interface(s) is where any and all external audio gets input and output. So for me, the converters and monitoring these provide are the cornerstone because they do dictate the sound going in and coming out. I bought the apollo as my "mobile" DA unit, but it wound up becoming my monitoring box as well as a "backup" for the Lynx.