Amplifiers provide the power and volume for home electronics such as home theater systems and two channel stereos. The power ratings for home stereo amplifiers and car amplifiers are measured in watts. Stereo components such as receivers measure watts in stereo, or per channel. Some amplifiers have as little as three watts per channel, while other amplifiers are capable of 1,000 watts or more per channel. How much power you want or need in an amplifier depends on the size of your listening room and your budget. Ironically, the more watts an amplifier puts out does not necessarily mean it will be louder than an amplifier with lower wattage. When an amplifier reaches its maximum volume, it runs out of headroom and starts to distort. The more wattage an amplifier has, the more headroom it has before distortion. A 50 watt amplifier can be just as loud as a 100 watt amplifier, but the 100 watt amplifier will have more headroom and not distort as early as the 50 watt amplifier. Distortion is not desired in stereo amplifiers, and amplifiers that don’t distort are referred to as having a cleaner sound. Many audiophiles prefer higher wattage amplifiers because of their ability to accurately reproduce the concert experience. There are three types of amplifiers, tube amps, solid state amps and hybrid amps. Hybrid amps use both tube and solid state circuits. Many musicians and music fans prefer tube amplifiers because they believe tubes produce a warmer and smoother sound. If you buy a tube amp, you will have to replace the tubes periodically, while solid state amps use transistors which are considered more reliable than tubes.