AMPs
Crank up the volume! How many times have you heard your kids say it, and how many times have you told them, "Turn it down!"? Everybody knows that behind that cranked-up volume is usually an amplifier, but do you know what amps do? Amplifiers aren't just for teenagers who want to 'feel the noise' of their favorite music played on their favorite audio gear. They're also used to help people who have trouble hearing listen more effectively to the world around them. In fact, amplifiers are used in every device we use in our everyday lives that has an audio component to it, including computers, radios, hearing aids, televisions, CD players, and more. So how do these gadgets work? Who invented them, and how long have they been important to our lives?
History
Audio amplifiers are devices used to increase the volume of sound. They're not only important, however, because they increase sound volume, but because they take weak signals and make them stronger. In recorded history, the first known amplifier was created by Thomas Edison and was first used by him in 1877 in his phonograph. In 1906, an American engineer named Lee de Forest, who by his death had more than 180 patents to his credit, used an audio amplifier in the form of a triode vacuum tube, which he actually devised out of his own invention called the 'Audion.' Though the Audion was a breakthrough in radio, it did not amplify sound. He built on his invention and came up with an amplifier known as a 'triode,' which was a vacuum tube that had the capability of adjusting the movement of electrons from a filament to a plate, thereby regulating the sound. Later, de Forest, who called himself 'the Father of Radio' because his device was essential in the development of radio, was quoted as saying, "I discovered an invisible empire of the air ... intangible, yet solid as granite." These remarkable electronic components launched the field of electronics.
How amps work
Sound is created when an object vibrates in the atmosphere because it moves the air particles around it, which in turn move the air particles around them and carry those vibrations, mostly through air. Ears then pick up the changes in the air pressure and convert or translate them into electrical signals that the brain can better process. Amplifiers, or 'amps,' are the electronic parts that boost electrical currents used in devices that need the production of sound. Amps take the signal or input and boost the signals many times before feeding them into loudspeakers. The gauge of difference amps make is the ratio of the output signal to the input signal. This measurement is called the 'gain factor' and is expressed in decibels. For example, if an amp doubles the size of the signal, the gain factor, therefore, would be 2. But don't make the mistake of thinking the only thing amps do is boost the signal and augment the sound. Another job of an amplifier is to reproduce the integrity of the original sound, or the input signal. No small job, especially since the frequency and amplitude (magnitude) of input signals often continuously vary, sometimes by dramatic degrees. In other words, it must turn a small electric current into a big one. Amps have as an essential element an electronic component called a 'transistor.' A transistor is a semiconductor, which is made by man to control the flow of electricity; it conducts electricity at certain times, and does not conduct it at other times. Because these electronic parts are able to amplify and switch electronic signals, the output of power can be controlled.
Types of amps
There are four basic types of amplifiers, including 'voltage,' which is the most common type, wherein an input voltage is amplified to a larger output. The second type is 'trans-resistance,' which reacts to a changing input current by transmitting a related changing output voltage. Another type of amp is the 'current' amplifier, which also changes an input current to larger output. Unlike a voltage amp, however, which has a high input impedance and a low output impedance, a current amplifier has a low input impedance and a high output impedance. (Electrical impedance is defined as the measure of opposition presented to a current when voltage is applied.) The last type is a 'trans-conductance' amplifier, which reacts to a changing input voltage by transmitting a related changing output current.
Thanks to Edison, de Forest, Fender, and all the innovative minds of their time who invented and built on the audio creations that came before them, we now enjoy the many benefits of amplifiers in just about everything we do in our society today. For, without amplifiers, we would not have any of the modern devices that make our lives easier and richer. By boosting weak signals and augmenting volume, these wonderful inventions help to better connect us to the world and the people around us.
History
Audio amplifiers are devices used to increase the volume of sound. They're not only important, however, because they increase sound volume, but because they take weak signals and make them stronger. In recorded history, the first known amplifier was created by Thomas Edison and was first used by him in 1877 in his phonograph. In 1906, an American engineer named Lee de Forest, who by his death had more than 180 patents to his credit, used an audio amplifier in the form of a triode vacuum tube, which he actually devised out of his own invention called the 'Audion.' Though the Audion was a breakthrough in radio, it did not amplify sound. He built on his invention and came up with an amplifier known as a 'triode,' which was a vacuum tube that had the capability of adjusting the movement of electrons from a filament to a plate, thereby regulating the sound. Later, de Forest, who called himself 'the Father of Radio' because his device was essential in the development of radio, was quoted as saying, "I discovered an invisible empire of the air ... intangible, yet solid as granite." These remarkable electronic components launched the field of electronics.
How amps work
Sound is created when an object vibrates in the atmosphere because it moves the air particles around it, which in turn move the air particles around them and carry those vibrations, mostly through air. Ears then pick up the changes in the air pressure and convert or translate them into electrical signals that the brain can better process. Amplifiers, or 'amps,' are the electronic parts that boost electrical currents used in devices that need the production of sound. Amps take the signal or input and boost the signals many times before feeding them into loudspeakers. The gauge of difference amps make is the ratio of the output signal to the input signal. This measurement is called the 'gain factor' and is expressed in decibels. For example, if an amp doubles the size of the signal, the gain factor, therefore, would be 2. But don't make the mistake of thinking the only thing amps do is boost the signal and augment the sound. Another job of an amplifier is to reproduce the integrity of the original sound, or the input signal. No small job, especially since the frequency and amplitude (magnitude) of input signals often continuously vary, sometimes by dramatic degrees. In other words, it must turn a small electric current into a big one. Amps have as an essential element an electronic component called a 'transistor.' A transistor is a semiconductor, which is made by man to control the flow of electricity; it conducts electricity at certain times, and does not conduct it at other times. Because these electronic parts are able to amplify and switch electronic signals, the output of power can be controlled.
Types of amps
There are four basic types of amplifiers, including 'voltage,' which is the most common type, wherein an input voltage is amplified to a larger output. The second type is 'trans-resistance,' which reacts to a changing input current by transmitting a related changing output voltage. Another type of amp is the 'current' amplifier, which also changes an input current to larger output. Unlike a voltage amp, however, which has a high input impedance and a low output impedance, a current amplifier has a low input impedance and a high output impedance. (Electrical impedance is defined as the measure of opposition presented to a current when voltage is applied.) The last type is a 'trans-conductance' amplifier, which reacts to a changing input voltage by transmitting a related changing output current.
Thanks to Edison, de Forest, Fender, and all the innovative minds of their time who invented and built on the audio creations that came before them, we now enjoy the many benefits of amplifiers in just about everything we do in our society today. For, without amplifiers, we would not have any of the modern devices that make our lives easier and richer. By boosting weak signals and augmenting volume, these wonderful inventions help to better connect us to the world and the people around us.