The Rolls RA-53b is a 5-channel headphone amplifier with high gain reserves. The five 6.3 and 3.5 mm stereo jack outputs are parallel. The output level can be individually adjusted by separate volume controls per channel. When two RA-53b are mounted in a standard rack, both devices are connected via a link bus, so that a total of 10 outputs are available. In addition to the three stereo inputs and one mono jack input, three jack inserts are available for the first three channels.