Plinius SA-50 instruction manual. Page 21
WHY IS CLASS A BETTER?
Class A has always been regarded as the perfect operating mode for audio amplifiers. Many leading
amplifier designers and manufacturers world wide recognise that a well designed Class A circuit has
inherently lower distortion than any other design.
A Class A circuit topology is one in which the total current the amplifier is capable of delivering, is kept
flowing in the circuit regardless of demand. In a conventional for Class AB amplifier circuit this current
flow varies when demand varies.
Further, as current varies, the voltage on the rails (as seen by the output stage) varies too. In a Class A
circuit, current draw should be constant therefore there is an absence of the power supply modulation
common in Class AB design amplifiers. Pin point images, tonal clarification, intertransient silence, more
readily defined dynamic shading, inner detail and authority are all the stuff of good Class A design.
