How Does An Electric Guitar Work? The electric guitar is considered as among the most culturally critical 20th-century inventions, mainly because of its rock and roll connection. Indeed, it’s considered as the quintessential instrument for the music genre! But when it was invented in 1932, its early adopters were jazz musicians, while its early proponents were Les Paul, T-Bone Walker, and Lonnie Johnson.
A Must-Read: How Much Does An Electric Guitar Cost?
Through the years, it became a guitar that uses single or multiple pickups in converting the strings’ vibrations into electrical signals. The signal is created through electromagnetic induction, followed by feeding into an amplifier, and finally sent to the speakers where audible sound can be heard. The Donner DST-1B full-Size 39” electric guitar is an excellent example of a modern electric guitar suitable for beginners and guitar gods.
The Role of Pickups
Most electric guitars have solid bodies, while others have either a hollow or semi-hollow body similar to acoustic guitars. The difference means that plucking the strings on an unplugged electric guitar won’t produce an audible sound, unlike in an acoustic guitar. It is because an electric guitar doesn’t have a hollow body and a soundboard that will magnify the strings’ vibrations when plucked, strummed or picked.
It is where the single or multiple pickups on an electric guitar come in. An electric guitars sense, so to speak, the strings’ vibrations in an electronic manner and then directs the electronic signal to its amplifier and speaker. It is the reason why an electric guitar setup isn’t just the guitar itself but these two vital components.
An electric guitar has built-in magnetic pickups under the strings on its body. The pickups typically consist of a bar magnet surrounded by fine wire, as many as 7,000 turns or more in some models. The combination of the magnet and coils transform electrical energy into motion and motion into electrical energy.
This principle of electromagnetism underlines the creation of sound in an electric guitar. When you pluck, pick or strum on its steel strings, it creates vibrations in these strings. In turn, a corresponding vibration is created in the bar magnet’s magnetic field, which produces a vibrating current in the coils.
The vibration is the start of the sound creation, but it requires an amp and speaker for the sound to be heard by the human ear.
Pickups in electric guitars come in several types including:
- A single magnet bar underneath the six strings
- A separate polepiece corresponding to each string
- Multiple screws are used for polepieces. For this reason, their height can be individually adjusted (The proximity of the polepiece to the string has a direct effect on the strength of the signal. The closer it is, the stronger the signal)
Many electric guitars have multiple pickups, usually ranging from two to three, placed at different points of the body, too. Every pickup creates a distinctive sound, and multiple pickups can be paired to create variations of sound. The pairings are usually in-phase or out-phase.
Surprisingly, the pickups transmit signals through a relatively simple circuit. Its parts include:
- An upper variable resistor makes adjustments to the tone.
- ·A resistor and a capacitor are the low-pass filters that remove the higher frequencies. The resistor is typically 500 kilo-ohms max, while the capacitor is 0.02 microfarads.
You can adjust the resistor to remove the undesirable frequencies and to control the signal’s volume. The signal will be sent to the jack and then to the amplifier before it’s heard as audible sound in the speaker.
The Amplifier’s Role
Take note that most electric guitars don’t use electrical power, and these don’t have to be plugged into a power supply. But some models have active electronics with an onboard battery for power. The strings’ vibration creates an unamplified signal in the pickup coil that then feeds into the amp.
It is where the amplifier, or amp, comes in. It takes the unamplified signal, boosts it, and makes it audible, so it drives a speaker. It’s also part of the instrument, so, in most cases, an electric guitar doesn’t need an external amp. But many guitarists still use an external amp for increased volume.
Unlike a stereo amp, an electric guitar’s built-in amp is designed to create both distortion and a clean sound. The integrated amp also creates feedback loops wherein the string continues to vibrate indefinitely from a single note. Musicians often use feedback loops and amp distortion in creating special effects.
The degree of distortion is based on the type of electric guitar. The Gibson ES-175 guitar with ’57 Classic Humbucker pickups, for example, doesn’t have distortion while the Gibson SG ’61 Reissue guitar with ’57 Classic Humbucker pickups has heavy distortion. The Les Paul Custom guitar with 490R and 498T pickups has mild distortion.
(Read the Gibson ES175: History and Players book for more information about the iconic guitar that’s been used by legendary guitarists)
The last part of the chain is the speakers where audible sound can finally be heard. The guitarist’s skill in playing the electric guitar determines whether the sound heard is an unpleasant screeching sound or an otherworldly sound worthy of Prince.
The speaker works in the same way as a dynamic loudspeaker with a few differences. In it, the speaker cone and the voice coil (a cylindrical coil of wire) are attached; the voice coil itself is placed in a narrow gap and surrounded by a permanent magnet.
The voice coil turns into an electromagnet when an electrical current passes through it. The current is either attracted to or repelled by the permanent magnet. It depends on its direction that, in turn, moves the speaker cone back and forth. The sound waves are created when the air in front of the speaker cone moves.
We then hear the sound that was first created when you plucked, picked, or strummed on the steel strings. But the speakers’ role isn’t just making the original sound audible to the human ear, perhaps a hundred times louder. The speaker setup can mean the difference between an electric guitar sounds like it should and sounding like it shouldn’t.
To conclude, knowing the way that an electric guitar works will increase your appreciation for its beauty and the beautiful music you can make with it. You may want to learn more about the principles that underline its workings so you can understand the practices that the great guitarists do to their instruments.