The M845 mono power amplifier is a single ended design based around the 845 power triode. Operating in Class A and giving 27 Watts of output power, it will complement a wide range of medium to high efficiency loudspeakers.
The 845 triode was originally developed by RCA in 1931 as a radio transmitting and audio amplification valve. The anode is machined from solid graphite to allow high power dissipation. It has an extremely linear transfer characteristic.
In recent years, a renewed interest in this kind of valve has resulted in them being manufactured again by various factories in China.