Amplifier

Player
 
Interface
 
DAC
 
Amplifier
 
Speaker

amplifier:

Equipment capable of amplifying an incoming signal to a higher voltage or current. Equipment called amplifiers for short are usually integrated amplifiers. The name comes from the fact that in these devices sound processors, preamplifiers and power amplifiers are integrated into one housing. <--!-->

Class A amplifier:

Amplifier whose amplifying elements are constantly open. This is achieved by passing through them a current equal to or greater than the power output even at rest.
Class A amplifiers have no zero-transition distortion and have less harmonic distortion at low volume than Class B models because the amp elements operate more smoothly due to higher rest current. Due to the high resting current consumption, there is no signal-dependent distortion due to the power supply. Class A amplifiers require significantly fewer components, allowing for simpler designs. 

Class B amplifier:

An amplifier in which, at rest, only a small current is flowing relative to the strength of the signal output, which is achieved by processing the negative and positive half-waves of the signal relative to the zero point by separate semiconductors. The "classification" depends on whether the amplifier element is constantly running current or, in some cases, locks. Class B amplification requires two amplifier elements that take control from each other. There are several possible transitions between pure B-class and pure A-class setups, in which case there is a state where both amplifier elements lead and control is taken over continuously. This is called a Class AB setting.

Digital amplifier:

An amplifier that uses digital switching technology to produce an output signal of sufficient power. Digital amplifiers receive the signal from digital broadcast sources directly and process them without conversion. Their efficiency is over 90%, so they do not require special cooling and their material requirements are low.