Most USB mixers send the stereo-mix to the USB bus so you probably can't record the 3 mics on 3 different channels. There are some higher-end units that also work as a multi-channel interface.but I am apprehensive because audacity may not have the ability for separate tracks with what I have. does this sound right?
And, Audacity seems to "have trouble" with multi-track recording, at least with Windows... It might work better with a Mac, but I don't know.
I'd say your mixer "doubles as a (probably stereo) audio interface."do I HAVE to have an audio interface??