Guitar pickups are the critical, essential link between the guitar and the amplifier, transmitting the guitar’s signal to the amplifier while also acting as sort of a gatekeeper by boosting and cutting certain frequencies coming from the guitar.
While a guitar’s tone woods and construction account for much of its overall tonal characteristics, the pickups are the source of a guitar’s primary tone, shaping its personality by sculpting the guitar’s inherent acoustic tone into something that is more refined, sonically attractive, articulate and dynamically responsive before it reaches the amp and speakers for further tone shaping.
One of the easiest, fastest and sometimes even cheapest ways to significantly improve a guitar’s tone is by upgrading its pickups. Simply put, a poor set of pickups can make a great guitar sound lousy, but a great set of pickups can make a cheap guitar actually sound pretty good.
While changing pickups can provide a guitar with a significant tonal makeover, a good set of pickups basically enhances what is already there instead of completely transforming a guitar into something else. One way to think of the process is like swapping engines in a car.
For this article we’ll be focusing exclusively on standard magnetic electric guitar pickups and not on other varieties such as piezo or other contact transducers, microphone-based pickups or optical technology.
A standard electric guitar pickup creates a magnetic flux field, which in turn magnetizes a string made of ferromagnetic material like steel or nickel. When the string is plucked, the vibrations of the magnetically charged string disturb the flux field. As the magnetic field fluctuates, the disturbances are transmitted through the wire coil as electrical current.
The overall design of a magnetic electric guitar pickup is very simple, but numerous variables such as the type and strength of the magnet size of the coil, size of the wire, wire material, wire insulation, number of windings, winding pattern, pole piece design and so on affect a pickup’s performance, output and tonal characteristics. While it’s important to be aware of these variables and how they can affect sound, don’t worry too much about the finer details unless you plan on designing your own pickups.
In the grand scheme of things, there are only two basic types of electric guitar pickups: single-coil and humbucking. A single-coil pickup generally consists of a coil of wire wrapped around a bobbin surrounding either individual pole pieces for each string or a single, continuous blade that extends across all of the strings. A humbucking pickup involves two wire coils placed either side by side or in a top and bottom stack configuration, also with the coils surrounding the pole pieces or blade(s).
Usually a humbucking pickup has a single flat, bar-shaped magnet placed below a side-by-side configuration of coils and centered lengthwise between each coil and its set of polepieces, which are made of ferrous material such as steel to conduct magnetism from the bar magnet and generate the magnetic field.
On a single-coil pickup and some stacked humbuckers, the pole pieces are usually made of permanently magnetized material, although many exceptions exist, like the P-90 pickup design, which features two bar magnets underneath the coil with ferrous pole piece screws placed in between the magnets.
In general terms, single-coil pickups tend to be smaller in size, have lower output and produce brighter tones with emphasized treble, but they also tend to pick up unwanted interference like 60-cycle hum. Humbucking pickups are generally larger, deliver higher output levels and offer warmer tones with pronounced midrange, while also eliminating most extraneous noise due to the noise-canceling properties resulting from using two coils with reversed polarity and the current flowing in opposing directions.
However, over time these distinctions have become blurred, and it’s now common to find humbucking pickups in smaller, Strat- and Tele-sized configurations, single-coil pickups with noise-canceling technology and many other variations.
Pickup covers protect the fragile wire coils from damage, but depending upon the material they’re made out of, they also can affect the pickup’s magnetic field and resonant peak. A cover that is made of ferrous material and/or plated with ferrous material (like nickel) will affect the pickup’s magnetic flux, but a plastic pickup cover won’t (which is why Strat players don’t remove the pickup covers).
When Seth Lover designed the original Gibson PAF humbucker, he experimented with a variety of different materials for pickup covers before making his final choice based on how it affected the guitar’s tone (part of the reason later Gibson humbuckers with chrome plating on the covers—instead of nickel—sound different). Removing the covers results in a different magnetic field that boosts output and treble frequencies slightly.
