I agree with scott. Mixer is truly needed for professional results. Unless of course, your sound card comes with built-in pre-amps and you need two kinds of pre-amps (line pre-amps and mic pre-amps). I have the SoloEX8 system and it has built in pre-amps (phantom power as well) for the first two inputs... but I would need a mixer for the rest of the 8 inputs. Delta 66 requires a mixer or external pre-amp box ( I think they call it the omni box)...