Difference Between Amplifier and Oscillator

Key Difference – Amplifier vs Oscillator

Amplifier and the oscillator are two essential components in electric communication though a difference can be noted between them based on their functions. Amplifier is the inception of the concept of communicating through a wire, and the oscillator is the key to the wireless revolution. The key difference between amplifier and oscillator is that the oscillator acts as a source while the amplifier acts as a multiplier.

What is an Amplifier?

An amplifier is a device which increases the amplitude of a certain electronic signal. It does not generate any periodic signal. Any signal generated in the amplifier introduces distortion to the output signal. A good amplifier should not alter the shape of a signal but should increase the amplitude. The output signal must be stronger than the input. It may be accounted with respect to voltage or current. Vacuum tube amplifier is the predecessor of amplifiers. Then came the most reliable solution; transistor amplifier. Sometimes amplifiers are classified as linear and non-linear amplifiers. The output of a linear amplifier is directly proportional to its input. Common audio amplifiers can be considered as linear amplifiers. If an amplifier is used in the front end of a signal flow, it is called a pre-amplifier. If it is located at the final stage, it is called as a power amplifier.  Moreover, amplifiers can be renamed by the place of use. Amplifiers which amplify Radio frequency signals are called RF amplifiers. Audible range amplifiers are called audio amplifiers. The quality of an amplifier depends on various parameters such as gain, slew rate, output impedance, total harmonic distortion, bandwidth, and signal to noise ratio.

The application of the amplifier is seamless. From the pocket radio to the most complicated spaceship, the amplifier is there where the amplification of a weak signal is needed. Let us pick a pocket radio as an example. There is an RF amplifier inside to amplify weak radio signals. The amplified signal is mixed with another signal and again amplified. Then the signal is demodulated, and the demodulated signal goes through an audio preamplifier. Finally, it is amplified by the final amplifier stage and fed to a speaker. Now we can listen to our favorite radio station. If we want more music, we have to amplify it again by an external power amplifier.

Difference Between Amplifier and Oscillator

Inside of an audio amplifier

What is an Oscillator?

The term oscillation is defined as the periodic motion around a fixed point. In electronics, the oscillator is a generator of the periodic electronic signal. Amplitude, frequency and shape are some characteristics of an electronic signal. Normally, an oscillator is used to generate single frequency at a time. Practically, they produce a range of frequencies around the desired frequency. They are built to produce various output waveforms such as sinusoidal, square and saw teeth. The frequency generated by an oscillator spreads from very low frequencies to high frequencies. Several classifications are available for oscillators. Generally, they are divided into three classes by the output frequency. Low-frequency oscillators produce frequencies lower than 20 Hz. Audio oscillators produce frequencies between 20Hz and 20 kHz. Oscillators which produce frequencies higher than 20 kHz are categorized into the RF oscillators. It is complicated to sink into the other oscillator types such as harmonic oscillator and relaxation oscillator since thorough electronics are needed.

Firmly tuned oscillator is the secret behind an accurate electronic clock. The crystal oscillator inside the clock decides the length of a second; consequently the right time. RF devices, Electronic musical instruments, and inverters consist of oscillators.Key Difference - Amplifier vs Oscillator

What is the difference between Amplifier and Oscillator?

Definition of Amplifier and Oscillator

Amplifier: Amplifier is an electronic device that is used to increase the amplitude of electrical signals.

Oscillator: Oscillator is an electric device that is used to generate  oscillatory electric currents or voltages by non-mechanical means.

Characteristics of Amplifier and Oscillator


Amplifier: Amplifiers do not produce any signal

Oscillator: oscillators are built to generate electronic signals.

Input and Output:

Amplifier: Amplifiers have both input and output while oscillators only have an output.

Oscillator: Nothing is fed to an oscillator to produce output. Oscillator, itself produces the output.


Amplifier: Amplifiers do nothing till input signal is fed to the input.

Oscillator: Oscillators produce signals from the moment of powered.

Image Courtesy:
“MissionCyrus1-2″ by Light current – en:MissionCyrus1-2.JPG. (Public Domain) via Commons
“Yellow-LED blocking oscillator 1″ by Wvbailey – Own work. (CC BY 3.0) via Wikimedia Commons