Pickup Basics
The simplest way to think of a pickup is “like a microphone for an electric guitar.” And have you ever noticed that if you pluck the string close to the bridge the note will sound bright and twangy, whereas if you pick right down by the neck you’ll hear a softer, rounder tone? Well if you place a pickup near the bridge of the guitar it will sound sharper and brighter compared to one that’s placed near the neck. This is why the majority of guitars have more than one pickup: so you can select different sounds from the full and warm to the thin and snappy.
From a mechanical perspective, a pickup is simply a magnet with a bunch of copper wire wrapped around it. The magnet creates its own magnetic field. The vibration of the metallic guitar string interacts with that field, and the changing magnetic flux induces a voltage in the coil of wire. This then gets sent to your amp where it’s turned into music. There are two main types of pickups: single coils and humbuckers. Let’s have a look at each, and what they do.
Single Coils
Single coils (like you might find on a Fender Telecaster or Stratocaster) have a clear, twangy sound, and they tend to sound really great through a clean, un-distorted amp setting. This type of single coil pickup is made by wrapping wire around six ‘slug’ pole pieces (which are held in place by flatwork to create a bobbin). A cover is usually placed over the pickup to protect the wire.
But single coils have a drawback: you’ll notice a bit of background buzz which is just part and parcel of the single coil experience. Some players swear by this sound because it’s a link back to guitar’s vintage past. Others want to get rid of it so they can only have the pristine single coil sound minus the hum. Various noiseless single coils are available from companies like Fender, DiMarzio, Kinman and Seymour Duncan. Single coils are great for country, blues, indie and alternative styles.
Humbuckers
The idea behind humbuckers is to use two separate pickup coils, each wound in a different direction, over a central magnet. The hum is cancelled out by the two different coil directions, and the overall tone is generally thicker, louder, warmer and fuller than single coils. Humbuckers are great for heavier styles like classic rock, hard rock and metal, and they can add some toughness and raunch to blues too. And the softer, smoother tone of humbuckers makes them great for jazz as well, especially if you use a humbucker in the neck position on a big hollow-body guitar.
You can use single coils and humbuckers in the same guitar. Popular configurations include a humbucker in the bridge position with single coils in the middle and neck spots; humbuckers in the bridge and neck with a single in the middle; or a single coil in the bridge position of a Telecaster with a humbucker in the neck position.
But What Are P90s?
The P90 is a single coil too, but it’s larger than a Stratocaster-style single coil, and its sound is edgier, rattier and hotter. It’s a great choice for alternative, punk, country and blues, goes great with slide guitar, and is even suited to styles like stoner rock and vintage metal: flip to the neck pickup of a P90-loaded guitar and play Black Sabbath’s “Paranoid” to see what I mean. Because they’re single coils, P90s are prone to the same noise issues. And just like other single coils, various companies also make noiseless versions to counteract this.
Active vs Passive Pickups
A passive pickup is the most common kind (to the point where people rarely even use the term ‘passive pickup’ unless they’re comparing it to an active pickup: they simply say ‘pickup’). An active pickup is usually wound much weaker than a passive pickup, but its signal is amplified from within the pickup itself, usually via an internal 9 volt battery. There are several advantages: the output is usually more powerful; there’s often more sustain; and the sound will stay intact even if you use a really long cable (whereas the signal of a passive pickup will degrade more and more the longer your cable is). Active pickups are available in humbucker and single coil versions, and they’re both very quiet. You’ll hear active EMG single coil pickups in the hands of Mr. David Gilmour in the 80s and 90s – Pink Floyd’s P.U.L.S.E live album and DVD is essentially one huge catalog of great active single coil sounds – while companies like EMG and Seymour Duncan make plenty of humbucker models that are great for heavier styes, where the power and clarity of an active pickup come in really handy during high-speed runs and palm-muted chugs. It’s generally very difficult to install active and passive pickups in the same guitar, so usually you’ll find one kind or the other, not both. If you’d like active and passive sounds in the same guitar, check out Fishman’s Fluence series, active pickups which offer several selectable sounds, usually a more active-voiced and a more passive-voiced one. I particularly like the Devin Townsend signature set.
Magnets
Whether you choose single coil or humbucker, active or passive, the size, type and configuration of magnet/s that you use in your pickup all have a big influence on the sound that the pickup produces, as does the type of wire: how thick it is, how it’s insulated, how it’s wound around the bobbins, how many turns of wire. For instance, if you add more turns of wire then the pickup will have a louder perceived output, but will lose treble frequencies. You can counteract this by using a stronger magnet instead of extra turns, or you can raise the height of adjustable pole pieces to get more treble back into your sound. And the closer the pickup is to the string, the louder the pickup will seem to be. Raise it too close to the strings though, and the pickup’s magnetic field will negatively affect the vibration of the string, leading to weird out-of-tune notes and/or a weird ‘wub-wub-wub’ oscillating overtone. And adjustable pole pieces can also help you to refine the magnetic field and its interaction with different strings. Is the B string a little quiet compared to the rest, especially when you’re running a clean tone? Well then, raise its pole piece a little to boost the height of the magnetic field in that section of pickup. Want less bass and output but more treble? Lower the pickup a little and raise the pole pieces. Easy! But let’s backtrack a bit…
All of these factors influence the sound of a pickup, but one of the easiest to quantify is the magnet type. There are a few magnets that are typically used in pickups, and by knowing a little bit about them you can more easily figure out which one might work for the sound you’re going for. We’ll start by looking at Alnico, an iron alloy which includes iron (of course), aluminuim (Al), nickel (Ni) and cobalt (Co), as well as a little bit of copper (Cu). (I guess when they were naming it they decided against Fealnicocu). The three most commonly used Alnico magnets for pickups are Alnico II, Alnico III and Alnico V, although Alnico VIII is also sometimes used. Let’s look a few of the most popular magnets, with a focus on how they apply to humbuckers.
Alnico III
It may be a little counterintuitive, but Alnico III is the weakest of the magnets used in pickups because it has no cobalt. But I guess it’d be confusing to just call it ‘Alni.’ It has the lowest magnetic pull, which means the strings are less influenced by the pickup’s magnetic pull, and this makes it a popular choice for neck pickups. It’s a little more ‘confident’ in its tone compared to Alnico II, although both exhibit a similar ‘softness.’ Many players like to balance an Alnico III neck pickup against an Alnico II in the bridge.
Alnico II
Alnico II is associated with the original PAF humbucker, and it’s still used today in a great number of pickups. The tone is relatively soft and clear, often described as sweet, with a slight rounding off of the more brittle treble frequencies. It can sound very musical and mellifluous with a clean tone, and rather ’singing’ with overdrive. If you’re running a hotter, more distorted tone you may find that Alnico II humbuckers tend to provide excellent note separation for complex chords.
Alnico V
Alnico V pickups usually sound hotter and more ‘edgy’ than their Alnico II and III counterparts. They’re great at more aggressive tones and in situations where you need a little more ‘unity’ in your chords: notes may knit together a little more tightly when you’re chording through heavy distortion with an Alnico V pickup. It’s also a little warmer in the midrange, which makes it great for lead guitar.
Ceramic
Ceramic magnets are also used in some pickups. Their sound is usually characterised as more ‘modern,’ with a tighter low end, more ‘cut’ and higher output compared to Alnico magnets. You can usually bet that a ceramic-loaded guitar will sound pretty powerful, maybe with a little more bold midrange, especially in the upper mids. Some early ceramic pickups sounded rather flat and pinched, but as pickup companies further explored the capabilities of the magnets they discovered how to really get the most out of the tone.
Alnico VIII
Alnico VIII is probably the least common magnet type, but many players consider it to be an undiscovered gem, It gives you the power of a ceramic magnet but with the warmth and harmonics of an Alnico V, and is a great way of preserving some of the woodiness of your guitar tone while still hitting your amp with plenty of output.
What’s a split coil/coil tap?
Many players confuse ‘coil split’ and ‘coil tap,’ using the terms interchangeably, but they’re actually quite different. A coil split involves a humbucker pickup whose wiring lets you essentially switch one coil off, thereby turning it into a single coil. Many players like having the tonal flexibility of having single coil and humbucker tones available in the same guitar. Unless you’re buying an intentionally vintage-styled pickup, most pickups these days come with four conductor wiring as stock. That usually entails four separate wires (a ‘start’ and ‘end’ for each pickup coil), plus a ground wire. You can have your guitar wired so you can turn off one coil via a push-pull switch built into a volume control, or you can use a separate toggle switch, or (depending on the type of switch you’re using) special custom wiring. You will get single coil hum when using single coil mode, but not humbucker mode.
A coil tap is different: it involves a single coil pickup which is made with an extra wire coming off it to give you two different levels of output. The full output and a lower ‘tapped’ output. Again you can use a push-pull knob, a toggle switch or special wiring to engage the tapped mode. The benefit here is that you can have a ‘full-power’ sound for solos and huge riffs, then flip to tapped mode to reduce the output, distortion and volume for quieter moments when you need to drift into the background a bit.
Acoustic Guitar pickups
Amplifying an acoustic guitar can be tricky. Part of what makes an acoustic guitar great – perhaps the most major part, really – is the resonance that occurs within the body itself. But the most popular type of pickup for acoustic guitars is the piezo element, which lives underneath the bridge saddle and translates the vibration of the strings through the bridge into amplifiable sound. But this process gives you a distinctive harsh ‘quack’ tone which you then need to either live with or eliminate. There are plenty of preamps and outboard devices out there which superimpose ‘profiles’ of different acoustic guitars onto your piezo sound, thickening it up and greatly reducing the synthetic effect of the piezo pickup.
There are a few other options though (other than simply micing your acoustic guitar up with a microphone or two, which can be great in the studio but problematic in a live environment). One is a magnetic pickup, much like those used for electric guitars. These still pick up the sound of the strings themselves, rather than the strings as resonated through the body, but the effect is much warmer and less harsh and brittle than a typical unprocessed piezo element. The other option is an internal microphone system, which will give you a much more accurate reading of the actual sound of your guitar. There are some units which combine several of these options – for instance an internal mic for the resonance and a magnetic or piezo pickup for the detail, with the ability to blend between them. Some of these systems come as stock equipment in the guitar when you buy it, while others will need to be installed, either by yourself or a competent technician (depending on complexity of the job: some simply pop in while others need a little bit more work).
Technical Terms
Pole Piece: A metal slug or screw which corresponds to each individual guitar string, focusing the pickup’s magnetic field at the optimal position to do its job.
Coil: The basic structural foundation of a pickup: wire wrapped around pole pieces, either as a self-contained unit (in a single coil) or as part of a slightly more complex assembly which shares a single magnet (humbucker).
Single coil: a pickup style which provides excellent clarity and translation of the sound of the string, but which is susceptible to certain kinds of background hum.
Humbucker: a pickup designed to eliminate the hum of single coils by cancelling it out with an opposite coil. It has more power and a thicker, warmer sound than a single coil.
Trembucker: Seymour Duncan’s term for a pickup whose pole pieces are spaced slightly wider apart for a guitar with a Fender or Floyd Rose-style bridge.
F-Spaced: DiMarzio’s term for a pickup whose pole pieces are spaced slightly wider apart for a guitar with a Fender or Floyd Rose-style bridge.
Coil Split: A type of wiring option which ‘turns off’ one coil of a humbucker to approximate the sound of a single coil. Usually requires a pickup with four conductor wiring.
Coil Tap: A type of wiring available with certain kinds of single coil where a ‘tap’ is run off the wire at a certain point, giving you two selectable power levels.
