Any professional guitarist or serious collector knows the difference between good tone and bad tone when they hear it. However, that doesn’t always mean they know exactly how to get the best tone with any instrument. And while the perfect tone is a subject of endless discussion, every guitarist needs to understand the basic concepts behind one of its biggest factors: a guitar’s pickups.
So how do pickups work?
Pickups use the law of electromagnetic induction to reproduce guitar string vibrations as an electrical signal that can then be amplified. A typical pickup design consists of a magnet and a coil of fine wire. The magnet is used to polarize the strings, and as they vibrate it creates a changing magnetic field within the coil. The coil responds to each string oscillation by inducing a voltage of alternating polarity.
How do pickups affect tone?
Since guitar strings can produce different overtones in different locations, the placement of the pickups beneath the strings has a lot to do with it. Bridge pickups tend to produce a “brighter” sound, while a neck pickup may not produce as many overtones, resulting in a “darker” sound. Because the vibrating strings’ amplitude is greater near the neck and smaller at the bridge, pickups must be carefully biased for the correct volume output at each position.
What’s the deal with humbuckers?
Guitars with single coil pickups often reproduce electromagnetic interference from nearby power lines and radio waves. This is audible as an annoying buzz that comes through the amplifier. “Hum-bucking” pickups were invented as a way to eliminate this noise. They work by using two coils which are wired in opposite directions. This results in the hum being canceled out while the signal from the strings is reinforced. This more powerful signal is great for natural high gains that can’t be found in a single coil.
Single coil pickups and humbuckers are both popular designs, and owing to the different quality of tone they produce, many guitars have a combination of the two. It all depends on the type of playing you do. Stop by our Greensboro guitar shop to learn more about pickups and play both kinds!