Power amplifier, control method thereof and vehicle-mounted audio system

The invention discloses a power amplifier, a control method thereof and a vehicle-mounted audio system. The power amplifier comprises at least two first bridge type amplifying circuits and at least two second bridge type amplifying circuits; the negative electrode of the first load of each first bridge type amplifying circuit is coupled with the positive electrode of the second load of each second bridge type amplifying circuit through a gating circuit; when an input signal input by a first signal input end of the first bridge type amplifying circuit is smaller than a preset threshold value, the gating circuit is conducted, and the first load current of the first bridge type amplifying circuit is transmitted to a second load of the second bridge type amplifying circuit through the gating circuit. According to the scheme, the efficiency of the AB type power amplifier can be improved. 本申请公开了一种功率放大器及其控制方法、车载音频系统。其中，所述功率放大器包括：至少两个第一桥接式放大电路以及至少两个第二桥接式放大电路；每个所述第一桥接式放大电路的第一负载的负极分别通过一选通电路与每个所述第二桥接式放大电路的第二负载的正级耦接；其中，在