Feedforward amplifier circuit, audio amplifier and audio playing device

A feedforward amplifier circuit, comprising:

• a main amplifier circuit, an adder circuit, a sub-amplifier circuit and a subtractor circuit, wherein
• the main amplifier circuit adds distortion to a first input signal to output a distorted signal, and inputs the distorted signal to the adder circuit and the subtractor circuit for performing feedforward correction;
• the sub-amplifier circuit amplifies a second input signal and serves as a positive input of the subtractor circuit, so that a signal gain output by a subtractor in the subtractor circuit is equal to a signal gain of a main amplifier in the main amplifier circuit;
• the subtractor circuit, with the distorted signal as a negative input, reversely amplifies the distorted signal and then performs feedforward;
• and
• the adder circuit superimposes the distorted signal output by the main amplifier circuit and a reversely amplified distorted signal output by the subtractor, so as to output a distortion-free signal;
• wherein the first input signal and the second input signal are consistent.