The RB-UL1 is a single stereo unit for interfacing domestic, or semi-pro unbalanced equipment to professional balanced line levels. The two RCA unbalanced inputs have an impedance of 10kOhms and are routed to two 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