There are several ways to classify a guitar amp: by the inches of the speaker, by the power, if they are open or closed … etc. However, the parameter that is really used to classify the amplifiers is by the element that is used in the previous stage and in the power stage: tubes or transistors.
Tube amps were the first to appear. The valves are vacuum tubes that, when heated above 100º Celsius, produce sound. This has the counterpart that they need a couple of minutes from when you turn them on until you can use them. So if you have half an hour a day to practice, they may not be for you.
They are also heavier, require more maintenance, and are more expensive. Be careful, I insist on maintenance; the valves wear out over time and have to be changed.
Reading through all these downsides, you’ll probably think that these amps aren’t the best option, but you’ll be surprised to learn that they’re the ones used by the most faithful and puritanical on guitar. Why? The reason is that the sound delivered by these amplifiers is of a higher quality than that of transistor amplifiers.
Transistor amplifiers are more practical because they have less maintenance and are less heavy. If you add to this that its price is lower, you have a perfect amplifier for those people who are starting to play the guitar.
With the idea of combining the best of each type of amp, hybrid guitar amps were born. Thanks to the combination of tubes and transistors, it is possible to have very good power and a warm and natural sound.
Equalization of an amplifier
Probably if you look at your guitar amp, you will see among other wheels, some with the name Volume, Gain, Bass, and Treble. And you’ve probably noticed that when you turn them one way or another, the sound of your amp varies. But do you know how they work? Let’s see:
These controls are actually variable resistors called potentiometers (or pots if you want to sound cool ) with which we can make various modifications to the signal.
Thanks to these potentiometers, we can expand or reduce the signal, filter the frequencies … etc. We better see each of them:
- Volume: sound volume, measured in decibels. It is in the pre-stage of the amplifier and provides the force of the sound.
- Gain: amplifies the signal. It is in the pre-amp stage. The higher the gain, the greater the distortion (overload) or fuzz. Therefore, with the gain, we control how clean or dirty we sound regardless of the volume.
- Treble: frequency of the treble tones. In other words, how sharp the sound is. It is in the pre-amp stage.
- Bass: frequency of low or bass tones. In other words, how bad the sound is. It is in the pre-amp stage.
- Master: we control the volume of the signal that we send to the speaker. It’s in the power stage.
Therefore, we have that the Volume, Gain, Treble, and Bass are in the previous stage, and with them, we control the shape of the tone. These buttons are also called equalizer frequency or simply equalizer.