Vacuum tube amplifiers (or valve amplifiers) are a type of electronic amplifier that uses vacuum tubes to increase the amplitude or power of a signal. Before the solid-state semiconductors appeared, vacuum tubes were fairly common. At that time, the latter conquered the active electronic components in most instrument amplifier applications.
Solid-state semiconductors, also known as transistor amps, took over since they are more affordable, easier to build, and require less maintenance. These amplifiers are heat and shock-resistant, so they reduce the weight of the amp. In contrast, tubes are not that resistant, and they require replacements and maintenance fairly often. Additionally, they can make amps impossible to operate when conflicts with the tubes evolve.
Features of Vacuum Tubes Amplifiers
Many guitarists prefer the sound that the tube amplifiers provide because they consider that their sounds are warmer and more natural. For this reason, these amps remain considerably popular. However, it’s true that vacuum tube-based circuitry is technologically obsolete.
How Tubes Work
Vacuum tubes operate by controlling electrons. A cathode is in the center of the tube’s glass envelope. This cathode heats up and carries a small positive charge that releases a gazillion electrons. Near it, you can find an anode, known as the plate in the guitar universe. The plate has a high positive charge that pulls negative electrons toward it. In comparison, the cathode’s small positive charge seems negative compared to the highly charged positive plate.
Electrons tend to move towards the plate when they are located in a powered-up vacuum. The flow of electrons might be controlled when you add a grid. Nevertheless, when the grid is close to the cathode and linked through the plate, small voltages appear. At the moment this happens, the signal releases a large number of electrons that begin to fly freely. While this happens, the rush of electrons echoes the signal from the guitar, thus intensifying it several times.
Conclusions
You can get a unique tube sound when the amplifier is activated. So, when talking about vacuum tube amplifiers, bigger is not always better. Experts recommend choosing a lower wattage amplifier and many professional guitarists agree, especially when they are recording and performing.
