The RB-UL2 is a dual stereo unit for interfacing domestic, or semi-pro unbalanced equipment to professional balanced line levels. The four RCA unbalanced inputs have an impedance of 10kOhms and are routed to four balanced XLR-3 outputs with an output impedance of <50Ohms. The output gain can be individually adjusted for left and right channels by using pre-set potentiometers accessible through the rear panel.