1. General amplifier can be divided into monster beats by dr.dre  transistor (stone machine) and vacuum tubes (bravery machine) amplifier two kinds.
2. Amplifier
The preamplifier and power amplifier collectively.
Power amplifier
“The power amplifier, used to enhance signal the power to drive speakers speak an electronic device. Don’t take the signal source selection, the volume control function of the power amplifier subsidiary called after class.
Before the power amplifier amplification and advance the control part, used to enhance signal voltage amplitude, provides input signal choice, tone and volume adjustment control etc. Function. The preamplifier also called the former stage.
3. The prevalence of amplifier (class-A)
Also called A kind of amplification. For a working state amplifier. At this time monster beats ibeats by dr.dre the transistor amplifier or vacuum tubes will be to the audio signal amplifier.
B amplifier (class-B)
Also called a class B amplification. For a working state amplifier. This time all the way transistors or vacuum tubes will enlarge the amplifier of audio is half part, and the other all the way transistors or vacuum tubes are magnified the signal amplifier negative half part.
A b amplifier (class AB)
Also called AB kind of amplification. The amplifier’s a kind of work condition. At this time the amplifier’s output level in power output for low electricity and the prevalence of at ordinary times according to enlarge state, and in the power output for high and converted to electricity at ordinary times when a amplification.