Anatomy of a Pickup

As musicians, most of us are a little tone crazy. Even though we might be getting a good sound out of our instrument, we just know that it could be better. There are many different elements that contribute to an instrument's tone, but the place most people start when they're dissatisfied with their sound is the pickups.

But how do we know which pickups will be right for us? There are dozens of manufacturers making countless different designs. In addition to the enormous number of options available, the sound one can expect from these pickups are described in terms like “bright”, “warm”, and even “round”. Who knew that tone could be described with shapes?

But how much does the average musician know about pickups? Do you know what they're made from? How they work? To most they are a puzzle inside a riddle within an enigma, but that doesn't stop us from dropping a hundred bucks on one in the hopes that it will finally fix our “tone jones”.

The truth is, pickups are incredibly simple devices that have much more in common with each other than differences. Let's start with the basics...

Fundamentally, pickups are magnets and wires. That's it. Basically, a length of wire is coiled around a magnet, and when a guitar string vibrates within the magnetic field it causes the coil to generate a voltage. This is the signal that your guitar or bass amp amplifies. Pretty simple so far, right?

Let's look at some of the variables that are involved:

Stronger magnets create a hotter signal, and the type of magnet also affects tone. Original Gibson PAF's are one of the most sought after sounds, and most people attribute their trademark tone to the Alnico magnets that were used. For this reason, Alnico II is often used in “vintage” replacement pickups, as they're thought to produce a vintage sound. Also common is Alnico V, which is slightly stronger, and produces a brighter, “punchier” tone. Ceramic magnets are stronger yet, and are commonly used in more modern, rock-oriented pickups.

Increasing the number of windings in the coils increases the output as well, but it also tends to accentuate the midrange while attenuating the lows and highs. As the number of turns increases, the tone gets muddier. Using a heavier gauge wire produces similar results.

Those are the basic building blocks of pickup construction, but another aspect of their design that greatly affects tone is the number of coils. Fender Strats and Teles historically sport a single coil design, as described so far, which tend to have a “bright”, “twangy” sound. But one shortcoming of the single coil pickup is it's tendency to pick up the 60 cycle hum produced by most electrical circuits – building wiring, lights, etc. In 1955 a Gibson employee named Seth Lover invented the Humbucker pickup. The humbucker has 2 coils wound with opposite electrical polarity and reversed magnetic polarity, which has the effect of canceling the hum produced by each individual coil. Due to the larger number of windings, and extra magnets, the effect on the tone is to generally produce a "fatter", more “midrangey” sound.

So what is it about the huge selection of replacement pickups on the market, ranging from inexpensive generic substitutes, to handmade “boutique” options that set them apart? Not really a whole lot, as you can see. In the end, after you absorb all of the hyperbole and metaphors, you just have to know what you're looking for and, most of all, trust your ears.