Amplifier facts for kids
An amplifier (often called an amp) is an electronic device. It makes sounds from things like a radio or an electric musical instrument (such as an electric guitar or bass guitar) much louder and stronger. You can find amplifiers hidden inside many electronic devices that make sound with loudspeakers. This includes televisions, radios, computers, and MP3 players.
How Amplifiers Work
Electronic amplifiers make a sound signal louder and stronger. They do this using special electronic parts called transistors or vacuum tubes. To work, amplifiers need to be connected to electricity or a battery. Once the sound signal is made louder, it needs to be sent to a loudspeaker so people can hear it.
Sometimes, an amplifier tries to make the sound louder than it can handle. When this happens, it adds something called distortion to the sound. Distortion changes the sound, making it sound different. Some amplifiers are actually designed to add a controlled amount of distortion.
- Distortion from transistors sounds different from distortion made by vacuum tubes.
- Many people say that distortion from tubes sounds more musical.
- Because of this, more expensive amplifiers often use tubes to create a special, controlled distortion.
- However, many amplifiers use transistors to create a "clean" sound, which means it has no distortion.
The History of Amplifiers
For many years, from the 1920s until the 1950s, electronic amplifiers used vacuum tubes. These tube amplifiers were quite heavy and produced a lot of heat. They also tended to break down often.
Since the 1960s, most electronic amplifiers have been built using transistors instead. Transistors are much lighter, cost less money, and are more reliable than vacuum tubes.
Images for kids
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Stereo audio amplifier with 2 × 50 Watt used in home component audio systems in the 1970s.
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De Forest's prototype audio amplifier of 1914. The Audion (triode) vacuum tube had a voltage gain of about 5, providing a total gain of approximately 125 for this three-stage amplifier.
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The four types of dependent source—control variable on left, output variable on right
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Power amplifier by Skyworks Solutions in a Smartphone.
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An LM741 general purpose op-amp
See also
In Spanish: Amplificador electrónico para niños
