The 112RD-50 model name of your amp indicates that it has a single 12" speaker, a reverb/distortion chassis, and 50 watts of output power. It features the hybrid-tube chassis with a single 7025 preamp tube and two 6L6 power tubes, two channels (each with independent volume, tone, and bass controls), and gain and reverb controls on channel 2. Channel 1 also has a bright switch, while channel 2 boasts a limiter switch.
Music Man amps were highly regarded when they were released and they continue to be a popular, yet cost-effective choice for vintage guitar amplifiers.