Use "a amplifier" in a sentence

1. A single-ended class A amplifier output transformer is huge compared to a push-pull class A amplifier of the same power level.

2. Common-emitter amplifier is a typical resistive class A amplifier.

3. For audio amplification, a class A amplifier can be either single-ended or push-pull.

4. You can, indeed have a true class A amplifier that operates in push-pull mode.