Using a "black box" model of an op amp, it behaves as a Class B amplifier because it provides a "push/pull" output in response to a + or - signal at the input.
However instead of a Class B configuration, the first stage of an op amp is the actually the familiar "differential configuration" with two common emitter amps connected in a "symmetric pair". The input to one of amps is grounded so the diff amp responds to the only to the difference in inputs.
However a Class B amp also responds to the difference between the input to the "complementary pair" and the ground line.
So why can't a Class B configuration be used instead of the differential? It seems more logical with the intent of a complete op amp to make its internal circuits function more like the black box model.
However instead of a Class B configuration, the first stage of an op amp is the actually the familiar "differential configuration" with two common emitter amps connected in a "symmetric pair". The input to one of amps is grounded so the diff amp responds to the only to the difference in inputs.
However a Class B amp also responds to the difference between the input to the "complementary pair" and the ground line.
So why can't a Class B configuration be used instead of the differential? It seems more logical with the intent of a complete op amp to make its internal circuits function more like the black box model.