Electric guitars are found in most modern music today. But may seem like a bit of a mystery. After all, they dont exactly make much sound. And why do they sound the way they do? Its a good question, and one that I would like to try to answer as best as I possibly can in this post.
The chain of sound in an electric guitar generally goes something like this: strings, pickup, amp, speaker. There are other little things along the way, such as effects peddles and stomp boxes, but in general thats what you will find.
Strings and Pickups
I suppose this is very basic but, at the start of the whole process, the guitarist plays a note. Now, you may think that there are microphones on a electric guitar but this is not the case. An electric guitar actually uses magnets to generate a signal that is sent to the amplifier. The pickups is actually a magnet (or in some cases multiple magnets) wrapped in a thin wire up to 7,000 times. When a string vibrates, it disrupts the magnetic field generated by the pickups. The disruption cause a weak single to be sent through the wire and to the amplifier. Most guitars will have multiple pickups at different spots on the guitar which generate different sounds.
Because most electric guitars are passive (i.e. consume no electricity) the signal coming out of the pickups is incredibly weak. It needs to be boosted to be loud enough to drive a speaker, this is where the amp comes in. A typical amp consists of a pre-amp and a power amp.
The role of the pre-amp is simply to boost the signal enough that it can be used by the power amp. During the pre-amp stage, effects such as reverb, delay, and distortion are also added to the signal to make the guitar sound the way that the musician wants it to.
Once I was playing my electric guitar for a few dozen people. During the time I was there, I had a young kid ask me why my guitar sounded weird. He said that he thought electric guitars sounded like this (and here he did a pretty classic electric guitar imitation). I had to explain to him that that is not actually what electric guitars sound like, but what many musicians made them sound like. In fact, an electric guitar actually sounds almost nothing like what comes out of the speaker. Its all about what you make of it in this pre-amp stage.
After the pre-amp stage the signal is sent to the power amplifier, where it is given its major sound boost before it is sent to the speaker and, in time, to you ears.
I hope this helped un-mystify the mystery around electric guitars. If you have other questions, feel free to leave a comment bellow and I will do my best to answer it.