A true USB Plug and Play digital to analog pro audio interface with full transformer balanced output isolation to eliminate earth loops / ground hum and other extraneous interaction noise and distortion. Features an Output Volume Control for easy level adjustment. The USB DI installs as a fully compatible generic USB audio device, requiring no special driver program installation on Mac OSX, Win XP and Vista. The front panel has a Type B USB input connector and two transformer balanced analog audio XLR Line out connectors for connecting to any standard balanced analog input. A status LED on the front panel indicates that the USB DI is connected and operating. USB bus powered.