Audio amplifiers play a key role in the sound performance of your hi-fi system. It is always said that the amplifier is the heart or the heart of a hi-fi sound system, and indeed it is.

A large part of the tonal imprint of the resulting sound will be given by the stereo amplifier of your choice. So pay close attention when you buy and value all the features that are important to you.

Over the years, a lot of progress has been made in high fidelity, but the main and most popular types of audio amplification are still as follows:

Solid State Amplifiers (FET or MOSFET type)

Solid-state audio amplifiers often use one or more field effect transistors (FETs). The main advantage of these transistor amplifiers is that they have a high input impedance and a low output impedance. Although many devices belong to this category, the most famous and appreciated are the amplifiers that use MOSFETs (Metal Oxide Semiconductor Field Effect Transistors).

Tube Amplifiers

Tube amplifiers use valves to convert an AC signal into a DC signal. The current obtained is the one that is then used to give power to the speakers. To achieve greater signal strength, combinations of several audio tubes are usually used.

Units that fall into this category of amplifiers are classified into two main groups: low power units and high power units.

High power tube amplifiers normally use a pentode-based electrical design, while low power tube amplifiers usually use single-ended (SET) triodes. SET tube amplifiers are preferred by enthusiasts with high-efficiency speakers.

Class A, Class B and Class AB

The class of an amplifier is directly related to the circuit design. Class A amplifiers always produce maximum output power even if they are not playing music. The advantages of this type of amplification is that it has very low levels of distortion.

Class B units are characterized by the tendency of transistors to remain in idle mode when there is no current and to activate them when a signal source passes through them. Although they are very efficient in operation, they are characterized by high levels of distortion.

Class AB is a combination of the two previous configurations (i.e. Class A and B). The signal drives a class A circuit, and when it stops, the amplifier switches to the second class B circuit.

Stereo, monoblock, and multi-channel

Stereo amplifiers normally drive a pair of speakers. Monobloc units, on the other hand, have great power and each of them can drive a single speaker. Multi-channel units are used for home theater applications and are designed to drive five or more audio channels; some newer models can drive up to seven channels simultaneously.


There are different types of audio amplifiers. Before you buy any model, we recommend that you analyze the technical specifications in detail to make sure you choose the best amplification for your needs.

For your own safety, whether you are interested in tube amplifiers or are moving towards a solid state amplifier, please contact us so that we can receive all the information you are interested in for free and advise you on the best choice.