Created as early as the 1930s, electric guitars feature a solid body construction, using pickups, amps, and speakers to obtain the loud volume and the specific distortions. If you already have the gear to become a rock star, including a motorcycle dolly, then you should also know what makes electric guitars unique, such as the loop feedback.
The electric guitar is, without a doubt, one of the most important instruments for shaping rock and roll music the way we know it. The range of sounds that it’s able to produce has defined the tone of music during the last decades, but some of you might not know that the first electric guitar was around as early as the 1930s.
However, at the time, few people thought that it was a good addition to the musical scene, and most definitely they didn’t see its huge potential and the major changes it led to in the next decades. Actually, it took electric guitars quite a long time to find their proper place within the American music scene and make their way toward other countries as well.
With this being said, today it’s easy to see that this instrument was the main driver of rock music and one of the most famous ones ever to be created in the United States. That’s why, for those of you who are passionate about electric guitars and the wide range of interesting sounds they can produce, this article is here to help you understand how they work.
Electric vs. acoustic guitars
If you’ve ever had the chance to compare an electric guitar with an acoustic one, then you surely know that there some important aspects that they share, such as the six strings construction, the tuning pegs, and frets that are positioned on a long neck. The major differences appear on the body end and the way it’s built.
While some electric guitars feature either a hollow or semi-hollow body, just as acoustic ones have, which means that the cavity is resonating, the most popular options on the market have solid bodies. This means that the sound is controlled through knobs and that it’s produced by using magnetic pickups.
If an electric guitar is not plugged in, the sound that the strings produce is barely audible, given that there is no hollow body or a soundboard to amplify the vibrations. For this reason, electric guitars might seem a bit odd at first for those who are used to playing acoustic ones.
A bit of history
Electrically powered instruments were a notion that engineers experimented with since the 1800s. Player pianos and music boxes were among the first examples of tools involved in such processes, but the idea of electrically amplifying sounds was not talked about until the 1920s, and the radio industry played an important role in this.
One of the first visionaries when it comes to music and sound was Lloyd Loar who, in 1924, worked on developing an electric pickup for instruments such as the string bass and the viola. In his designs, the vibrations produced by the strings were transmitted to the coil and magnet. Upon registering the vibrations, these two elements passed an electric signal to an amplifier.
In 1928 the first commercial electrical guitar was introduced to the market, and it used the same pickup principle, the vibrations being registered from the soundboard. While these early attempts to amplify the sound of a guitar were surely visionary, the signal was too weak. The solution came when a direct system that picked up vibrations from the strings was tested.
At that moment, the electric guitar as we know it became a reality, and the first commercially successful model was the one developed by Adolph Rickenbacker and George Beauchamp in 1932. This was known as the “Frying Pan” and it was the first step to bring a new sound to music on a larger scale.
In the following years, some musicians and instrument manufacturers began experimenting with recreating the same sound amplification but using a guitar made of solid wood. This meant that some of the issues associated with hollow-body instruments were solved, and the guitars also had greater sustain.
In the 1950s, Gibson brought a new model on the market, which was endorsed by Les Paul, a well-known guitarist. Once this happened, various rock stars began securing Gibson and Paul’s models throughout the 1950s and 1960s, which is what secured electric guitars a permanent place in rock music and American culture.
How do the pickups work?
The principle behind the way an electric guitar works is pretty simple. The vibrations produced by the strings are electronically perceived and then routed through an electronic signal toward an amplifier, in order to be then rendered by a speaker. A magnetic pickup placed under the strings is the element that senses the vibrations.
This simple, yet crucial, part of an electric guitar is made of a bar magnet, that is wrapped around with an impressive number of wire turns that can go up to 7,000. If you are familiar with the way magnets and coils work, then you surely know that these can transform electrical energy into something very useful in this process, namely motion.
Of course, the process can be reversed as well, and motion can be turned into electrical energy. When it comes to electric guitars, the string vibrations produce a similar vibration in the magnetic field around the magnet, which then translates into a vibrating current within the coil.
Pickups come in various types of constructions. For example, some can use a single magnet extended under all of the strings, while others can have separate pieces for each string. If screws are used for the individual polepieces next to the strings, this means that height can be adjusted, and a smaller distance between the two means that the signal is stronger.
The coil included in this process uses a simple circuit for most models. The variable resistor does the job of adjusting the tone, while a filter reduces higher frequencies. If you adjust the resistor you can easily control what frequencies are going to be cut out, thus obtaining more sounds. There is a second resistor that controls the signal’s volume (or amplitude).
The volume then reaches the jack that then runs the signal through an amplifier. The speaker is the final element that rendered the desired sound in this entire system. You will also see that many models have two or even three pickups on the body, placed at different points, and each one can create a different sound. These can also be paired for additional variations.
Distortion and amps
One interesting aspect of electric guitars is that most models are completely passive, which means that they don’t use power in order to work, so there’s no need to have them plugged into a power supply. However, the amp does play a major role, given that it’s its job to pick up the signal and render it audible by making it strong enough to go through a speaker.
It’s also quite fascinating that the amp is part of the instrument, so you cannot really think about an electric guitar without including it. However, this element is different from what one might think when it comes to an amplifier included in a stereo system.
While the latter is supposed to be transparent, which means that it reproduces and amplifies the sound without distortion, things are completely different for electric guitars. Musicians and artists are usually looking exactly for that distortion that results when the signal is too strong for the circuitry. That’s why many amps are specially designed to allow guitarists to control this distortion at the desired levels.
There’s another aspect that makes electric guitars unique, namely the feedback loops. If the sound produced by the amp and the speaker is loud enough, it causes the strings to vibrate as well, which means that a note can go on indefinitely. This is an effect that musicians can use to access a wider range of effects.
This feedback and the amp distortion are unique to electric guitars, thus helping experienced musicians get access to a range of sounds that is pretty much limitless. A regular amp consists of three main parts, namely a pre-amp, the power amplifier, and of course the speaker that renders the sound at the desired volume.
Some amp models can also include various reverb circuits and effects that work between the power amplifier and the pre-amp. In fact, the latter’s job is to make the signal strong enough so that it passes through the power amplifier stage.