<aside> ‼️ This manual was taken from the Church of the Highlands production team manuals and modified for our use.
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Amplification is the operation of an amplifier, a natural or artificial device intended to make a signal stronger.
Now that we know what amplification is, let’s gain a better understanding of how we make a signal stronger. We do this in the audio world with the use of amplifiers.
An amplifier is an electronic device that can increase the power of a signal (a time-varying voltage or current).
An amplifier uses electric power from a power supply to increase the amplitude of a signal. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output to input. An amplifier is a circuit that can give a power gain greater than 1:1.
In this definition provided by Wikipedia, you will notice one word that we have already discussed, Gain. Remember that we defined Gain as a change in level. You will see here that in an amplifier, Gain is described as a ratio of output to input. From this definition, we can better comprehend why we can increase or decrease gain. This ratio can move in either direction from a given point.
Here is a graphic representation of a circuit amplifying a signal.
Above is a graph of the input vi(t) (blue) and output voltage vo(t) (red) of an ideal linear amplifier with an arbitrary signal applied as input. Amplification means increasing the amplitude (voltage or current) of a time-varying signal by a given factor, as shown here. In this example the amplifier has a voltage gainof 3; that is at any instant vo=3vi.
Amplifiers can be categorized in different ways. One such way is by frequency of the electronic signal being amplified; audio amplifiers amplify signals in the audio (sound) range of less than 20 kHz. RF amplifiers amplify frequencies in the radio frequency range between 20 kHz and 300 GHz. Amplifier circuits can be made up of different electronic components.
The following is a series of descriptions of different classes of amplifiers. Do not try to memorize this information! It will not be on your assessment. I simply want you to know they exist.