What is an amplifier?An amplifier is an electronic device used to increase the amplitude of electrical signals. So basically, an amplifier's job is to take a weak audio signal and amplify it to create a signal strong enough to power a speaker. Amplifiers are used in many different audio systems today; including microphones, CD players, televisions and speaker systems. How does it work? An amplifier has many parts, but one of the most important parts is the transistor which is made of a piece of semiconductor. Before we get into how transistors work, we need to understand semiconductors. What is a semiconductor? A semiconductor is a material that conducts a current but only partially, so it is halfway between an insulator (does not conduct electricity) and a conductor (conducts electricity). Generally, a semiconductor is made of a poor conductor, such as silicon, to which impurities (atoms of another element) have been added; this process is called doping. In pure silicon, all silicon atoms bond perfectly to their neighbors, leaving no space for electrons to move around and conduct electricity. In doped silicon, additional atoms change the balance; either by adding free electrons or by creating holes where the electrons can go. There are two types of semiconductors; The N type is doped with phosphorus which adds free electrons (negative charge), and the P type is doped with boron to create holes (positive charge). Electric charge moves as electrons move from one hole to another, so either of these additions will make the material more conductive (Harris, 2002). Now that we understand a little more about semiconductors, we can look at how transistors work: How a Transistor Works: is a picture of ...... middle of paper ...... precision and sound quality . Class B amplifier needs transformers to operate efficiently, which is expensive. On the other hand, the Class A amplifier creates massive amounts of heat loss, and to reduce this impact, cooling and thermal regulation components must be purchased; which makes the class A amplifier also expensive. As both amps are expensive, the quality and efficiency of the amplifiers is the deciding factor. In a class B amp, only half of the sine wave is reproduced by each transistor, causing crossover distortion when the wave is cut off. This makes the sound quality fuzzy and unpleasant to the ears. In a Class A amplifier, a true reproduction of the original input wave is produced in the output, creating pure sound quality. As a result, I would definitely choose a Class A amplifier over a Class B amplifier because of the pure sound quality it produces..