Amplifier circuit

Is this a class-B amp?

It's Class AB audio amplifier

Sir, I have heard that class-AB amps contribute to high order harmonic distortion as compared to class-B ones. Is this relevant?

Class AB has less harmonic distortion. thanks.

Well, there is something called gm doubling which causes more distortion in class AB amps; I have to do more research on this. That causes harmonic distortion at frequencies where the feedback is too less. That's why most amps are class B type. Another replacement is the class XD amp. But I have no idea why class AB is not preferable. That's why I had asked.

Class AB amps can be called as over biased class B amps. Initially when the voltage increases, both the transistors conduct. This causes an output transconductance of 2/(Re+r'e ). As soon as the input voltage becomes sufficiently high, only one transistor conducts. Now, the output transconductance is 1/(Re+r'e); it has doubled now. This causes a gain change and thus an increase in THD with more power distributed amongst the high order harmonics, which the negative feedback network can't deal with as the dominant pole miller capacitor comes into action. That's why, class B amps are better than class AB ones as optimal biasing doesn't causes more than a few micro amps to flow.

Thanks