I'm running Ubuntu Studio (just upgraded to 14.10) with a Presonus AudioBox 2x2 USB audio interface. For Christmas I got myself a new MXL 990s condenser mic (60% off, sweet!), but when I plug it in ...
The portable audio interface rocks four combo XLR/0.25-inch instrument/line-in jack inputs and four low-noise microphone pre-amps with 48-V phantom power, as well as RCA and 3.5-mm connections.