The Yamaha M-65 is a stereo power amplifier featuring Zero Distortion Rule amplification and support for three pairs of speakers. It includes built-in protection circuitry to prevent damage from overloads and short circuits.
Key features include an Auto Class A switch that provides pure Class A operation at low volumes, shifting to Class AB for transient peaks when needed. The unit also offers independent level controls for the left and right channels and a power display with selectable impedance settings.
The minimum speaker load impedance for one speaker pair connected to terminals A, B, or C is 4 ohms per speaker.
If the PROTECTION indicator lights and output ceases, you should disconnect the plug from the AC outlet immediately to check for faulty speaker connections.
The circuit provides pure Class A power amplification for low power requirements but shifts to Class AB operation while transient peaks last.