Amplifiers, also known as an electronic amplifiers or amps, are electronic devices able to increase the power of a signal. This signal varies in time, voltage, or current. To further comprehend this, let’s remember that an amp is an electronic circuit that has two ports. It uses electric power generated from a power supply to increase the amplitude of a signal related to its input terminals.
An amp generates a proportionally greater amplitude signal at its output. Its gain is capable of measuring the amount of amplification offered by an amplifier, such as the ratio of output voltage, current or power to input. In brief, an amplifier is a circuit that has a power gain and it can be either a separate part of the equipment or an electrical circuit that’s in another unit.
Amplifiers: Main Characteristics
Musicians use amplifiers in a wide range of electronic equipment. In addition, they can be classified in different ways. For example, the first classification is about the frequency of the electronic signal being amplified.
There are many differences between audio amplifiers, servo amplifiers, and instrumentation amplifiers. Each one of them amplifies signals at a different range and at a different frequency. Which is why another classification relates to the physical space in the signal chain.
A Bit of History on Amplifiers
The first electrical unit that was able to amplify a signal was the triode vacuum tube. Years after, the launch of the first amplifiers came: and they are the ones we recognize today. Most of the amps common today use transistors to operate efficiently. Experts clarify, importantly, that the physics of the transistor determine transconductance of the input pair. It is not done so by matching other parameters such as beta, as some might believe.
A Final Note
Usually, the voltage signal at the Voltage Amplifier Stage (VAS) transistor base is just a combination of millivolts. It resembles a distorted triangle wave. The circuit topology involves a transconductance amplifier driving into a trans resistance stage.
