Wayne Parham Messages: 18791 Registered: January 2001
Illuminati (33rd Degree)
Not sure about the M-50, but I had two Yamaha amps in the late 1970's. The first used discrete bipolar transistors, the second used a large integrated circuit (about 3" x 2" x 1/2"). I don't know if the IC was proprietary or not but I suspect it was. It sounded better to me than the one with discrete components, but both were very good.