“We often get asked if 25 Watts of Pure class A is louder than an equivalent Class AB amplifier, the answer is yes and no. Both amplifiers will produce exactly the same power on a test bench but when it comes to listening to music, our Pure Class A amplifier can ‘sound’ a lot louder and more dynamic.
The way our Class A amplifiers work is very different from a Class AB design. When approaching maximum output our amplifiers have a soft clip and the distortion does not irritate the ear as it is mainly even harmonic and not odd. The output of the A21 amplifier is connected to the loudspeaker by a very large capacitor and this acts like a power bank to instantly drive the loudspeaker when demanded.” - Sugden Audio