I have previously owned a Presonus Firebox and an Audiobox 44VSL. Both devices would work as stand-alone preamp/mixers without connecting to a pc. On my limited budget this has been useful in simple audio performance situations. I just bought an 1818VSL for the extra inputs and it does not appear to have this capability. This does not make sense to me as it would be a trivial capability to build in. Have I missed something?