(2) The function of the front stage as amplification has disappeared, which mainly refers to the balanced adjustment of high and low tones.
(3) Digital power amplifiers refer to class D amplifiers, and the energy conversion efficiency is generally above 80%.
(4) Class A or Class A power amplifier refers to push-pull amplification, but the current at the working point is adjusted very high. Whether there is a signal input or not, it consumes electricity. This is commonly known as the electric furnace, with low efficiency, which is in sharp contrast with the above class D. In terms of sound quality, it is warmer than the class B, and there is no cross distortion.