Even with the affordability and ever improving sound of solid state amplifiers, many guitar players still prefer using tube amplifiers.
A tube, or valve, amplifier ("amp") is a kind of guitar amplifier that uses vacuum tubes to amplify a sound signal from a guitar.
Vacuum tube technology such as that used in tube amps was critical to the early development of electronics, but tubes have been largely replaced by solid state technology in just about anything that does not involve sound amplification.
Tubes sound great in guitar amps.
How They Work A tube guitar amp uses the low AC voltage coming from a guitar output and a high DC voltage coming from the power source to create sound.
The high voltage is applied to tubes that greatly amplify the low voltage coming from the guitar.
A lot of what goes on inside an amp doesn't even deal with the guitar signal, but with the management of the high power voltage.
There are basically two types of tubes used in a tube amp: preamp tubes and power tubes.
Power amp tubes are larger than preamp tubes, and serve the function of greatly amplifying the signal.
The smaller preamp tubes have more to do with coloring the tone of the signal.
At times, preamp tubes can also serve other functions, such as acting as a voltage rectifier.
A tube amp receives an audio signal from a guitar and passes it to the preamp tubes, which both amplify the signal as well as begins the process of coloring its tone.
Inside a preamp tube, there is a flow of electrons from one point to another that acts to increase the strength of the signal (also known as "gain").
It will flow through one or more preamp tubes before being passed to a series of potentiometers ("pots"), which are variable resistors that give the player controls to modify the tone and volume of the amp.
While the signal is passing from tube to pots and back, it is also passing through various resistors, which resist a certain portion of voltage, and capacitors, which absorb voltage for a time before releasing it.
These are standard voltage-manipulating components found in any electronic device.
This voltage filtering process is necessary to shape the guitar signal tone into one that is pleasing to listen to and that has a controlled amount of squeal.
Eventually the signal makes its way through the power amp tubes and then into an output transformer, which is a device that transforms the signal (a high impedance signal coming from the power tubes) into the type of signal that is required for the speaker (a low impedance signal).
And then you have sound! Compared to the internal workings of a typical solid state device, tube guitar amps are quite simple.
It takes a lot of signal processing for solid state amps to come close to replicating the beautiful sound of tube amplification, and even then an experienced player can tell the difference.
Reasons for its continued use Many music enthusiasts today still prefer tube amps because of the quality of sound it produces.
This is one of the many advantages of using tube amplifiers.
There are many audio technicians who claim that harmonic distortion coming from tube amps is clearer and more pleasing to the ears than those produced by transistor amplifiers.
Solid state amplification is chosen mainly because of its portability, low cost and reliability, but those who are most concerned with the quality of the tone use tube amps.
Tube amplifiers are easier to work on as well because the tubes and basic electronic components that comprise the amps are more straightforward that the inner workings of a complicated transistor amp.