There are two basic types of electric guitar pickups: magnetic and piezoelectric. Piezo pickups work with all kinds of strings (steel, nylon, or gut). Magnetic guitar pickups only work with steel strings. As for magnetic pickups, there are two varieties: Single coil, and humbucker.
How Magnetic Guitar Pickups Work A magnetic pickup consists of a magnet (pole) with a wire coil wrapped around it. When the metallic guitar string vibrates directly over the pole, it changes the magnetic flux of the magnet. This induces voltage in the coil around the magnet. The induced voltage oscillates in unison with string vibrations. That’s how the guitar pickup translates the mechanical string vibration into voltage oscillation which can be transmitted through wire to the amplifier.
The pickup assembly that’s visible under the guitar strings is a casing holding a series of magnetic poles – usually one per string. This series is connected to a master magnet that has another coil wrapped around it. On some pickups you can see the tops of the metallic poles, else they may be covered by a metal or plastic casing.
Single-Coil Guitar Pickups Single-coil guitar pickups consist of a series of poles in a single row, one for each string. These pickups produce a bright, cutting tone rich in higher harmonics. Typically single coils have that “twang” that’s heard in blues, country, and vintage rock, but not heard so much in heavier rock.
Sometimes single-coil pickups will produce an audible, 60-cycle hum when the guitar is in the presence of other electrical fields such as fluorescent lights and nearby transformers. One solution to this hum problem was the the humbucker pickup.
Guitars With Single-Coil Pickups Some popular single-coil guitars include:
Fender and Squier Stratocasters
Fender and Squier Telecasters/li>
Gibson Les Paul Junior with P-90 single-coil pickup
Epiphone Les Paul Special with P90 pickups
Humbucker Guitar Pickups
Humbucker pickups have two coils wrapped opposite from each other to cancel the 60-cycle hum. Humbuckers deliver a smoother, rounder tone. Humbuckers tend to generate more sustain than single-coils but with less note definition and high end. Some humbuckers are available with a coil-tapping control, that lets you use only a single coil in the pickup, thus generating the characteristic single-coil sound.
Guitars with Humbucker Pickups Popular guitars with humbucker pickups:
Gibson Les Paul and Epiphone Les Pauls
Gibson ES-335 and Epiphone Dot
Gibson and Epiphone SGs Guitars with Humbucker and Single-Coil Pickup Combinations Many guitar makers offer hybrid guitars with a combination of single-coil and humbucker pickups. Some models include:
Squier Affinity Stratocaster
Fender Classic Series ’72 Telecaster
Fender Stratocaster HSS
Piezoelectric Guitar Pickups On electric guitars piezos are typically individual elements incorporated in the string saddle. Piezos are made of a non-magnetic crystalline material that generates a weak signal when compressed. This signal must go to a preamplifier, which is usually built into the guitar. Once preamplified, the signal can be sent to an external amplifier. Some guitars with piezos feature a 13-pin output for synthesizer guitars. Otherwise, the piezo tone is used to approximate the sound of an acoustic guitar. Guitars with piezoelectric pickups Guitars with piezo pickups include:
Fender Acoustasonic Telecaster
Music Man Albert Lee MM90
Guitar Wiring Multiple pickups allow you to select options for a variety of different guitar tones. Pickups at the bridge will sample string vibrations where they have the least range of motion. This produces a biting sound with accentuated treble. Pickups located closer to the neck have more midrange and bass tones. Switches on the guitar let you activate an individual pickup, or a combination of pickups to produce different overall tones.
While there are many different wiring schemes, the most common are:
Five-position Stratocaster for three pickups Strats feature a five-position blade switch to control the guitar’s three, single-coil pickups:
First position – activates the neck pickup.
Second position – activates neck and middle pickups.
Third position – activates the middle pickup.
Fourth position – activates the middle and bridge pickup.s
Fifth position – activates the bridge pickup.
The Stratocaster also has a master volume control and two tone knobs that allow you to add or subtract treble tones. The front tone knob controls the neck pickup and the rear tone knob controls both the bridge and middle pickups.
Three-position Gibson Les Paul, SG and ES-3335 for two pickups Many of Gibson’s guitars with two humbuckers have a three-position toggle switch that lets you active neck only, bridge only, or both pickups.
Each pickup typically has its own independent volume control and tone control.
Jim Dunkerley is an avid guitar player and music lover. He discusses all things guitar at MakeGuitarMusic.com.