The McLELLAND MD-50 is a low cost, one-box solution in source selection and zone distribution, which designed to remotely adjust the volume of multiple amplifiers or powered speakers, either individually or in groups. The input of the MD-50 is connected to a PA Mixer’s line-level output (the MD-50 will accept the output of two mixers) and the power amps and/or powered speakers are connected to the MD-50’s zone output.