How an electric guitar works   by A1Muso

in Entertainment / Music    (submitted 2012-01-13)

Ever wondered how an electric guitar works? 

It's really quite simple and makes use of basic physics principals.

An electric guitar "senses" the vibrations / movement of the strings electronically. This electronic signal is sent to an amplifier and which is used to power a speaker.

The "sensing" is done using a magnetic pickup mounted under the strings which is essentially a bar magnet wrapped with thousands of turns of fine wire. 

Moving a magnetic field within a coil of wire can be used to generate electrical signals. Indeed this is how a power stations work where turning magents inside coils of wire 

generate current to power your home.

A similar pricipal is at work in an electric guitar where the strings vibration produces a corresponding vibration in the magnet's magnetic field which causes a virating electrical current in the coil.

There are many different types of pickups. For example, some pickups extend a single magnet bar under all six strings. Others have a separate polepiece for each string.

Some pickups use screws for polepieces so that the height of each polepiece can be adjusted. The closer the polepiece is to the string, the stronger the signal. The pickup's coil sends its signals through a very simple circuit on most guitars. 

Compenents such as a variable resistor are added to the simple circuit to adjust the tone.

A basic low pass filter (a resistor and capacitor) cuts out the higher frequencies and by adjusting the variable resistor you can tweak the frequencies that get through the filter.

The volume control is simply another variable resistor that limits the electrical current to the jack socket on the guitar.

Most electric guitars have two or three  pickups located at different points. Each pickup will have a different sound, and pickups can be paired and used together, used in and out of phase to create differnt sounds. 

From the jack a lead connects the guitar to the amplifier which essentially increases the tiny current from the guitar to something much more powerful which can then drive a loud speaker.

The great thing about even the most affordable electric guitars (under £200) is that they are modular and upgradable.

Pick-ups and circuitry can be changed by even an amateur should they wish to  upgrade their guitar as and when their budget permits.

So there you have it, electric guitars work on very simple components and basic physics principals!

About the Author

A1Muso is an online portal for Musical instruments, Guitars, Professional Audio, DJ, Disco, Karaoke, Lighting and effects equipment.

As well as selling products we reguarly blog and publish articles with information and advice about our products.