Are Class A amplifiers typically used as PA power amplifiers?

Class A amplifiers are generally not used as PA (public address) power amplifiers due to their inefficiency and heat generation. These amplifiers operate by having their output transistors conducting at all times, which results in high linearity and excellent sound quality but also leads to significant power loss as heat.

In PA applications, where high power output is necessary and efficiency is a priority, Class A amplifiers are typically less desirable than other amplifier classes, such as Class D, which offer greater efficiency and cooler operation. While they can be found in high-end audio applications where sound quality is paramount, their overall use in PA systems is limited because of the need for more efficient and powerful solutions.