You are here

A Comprehensive Guide to the Dizzying World of Electric Guitar Pickups

A Comprehensive Guide to the Dizzying World of Electric Guitar Pickups Two signature models from DiMarzio: Steve Vai Dark Matter 2 (left) and John Petrucci Sonic Ecstacy

HUMBUCKING PICKUP TYPES
Seth lover’s original humbucking pickup design, introduced on Gibson guitars in 1957 and nicknamed the “PAF” for the “patent applied for” decal affixed to the base plate through the early Sixties, remains the basic template for the majority of humbucking pickup designs produced today. However, there are several other popular classic variations, including Gibson’s smaller mini-humbucker and Firebird pickups, the Gretsch Filter’Tron and Fender Wide-Range (also designed by Seth Lover).

PASSIVE VS. ACTIVE
The most common distinction after single-coil/ humbucking is whether a pickup is passive or active. Passive pickups are the traditional wire coil/magnet/pole piece design, and they remain the most popular style of pickup on the market today. Passive pickups have a high-impedance design (low current, potentially high voltage), and output is usually increased by wrapping the bobbins with additional turns of wire and/or using more powerful magnets.

However, increasing the output of a passive pickup also can affect the tone in undesirable ways such as making the treble response too dark or shrill, and the pickups can become more susceptible to undesirable external noise. If the magnets are too powerful, a strong magnetic field can actually suppress string vibration, decreasing sustain and dynamic response—the reverse of the desired outcome.

Active pickups have similar basic construction to passive pickups, but the circuitry uses an active preamp (usually powered by a 9-volt battery) to boost the signal, allowing low-impedance designs (high current, potentially low voltage) incorporating fewer wraps of coil wire and less powerful magnets.

There are several benefits to this type of design: reduced noise (particularly with single-coil designs), higher overall output, consistent tone when turning down the volume control, no high-frequency loss when using long cables, consistent clarity and note-to-note definition whether using clean or high-gain distortion amp settings, and the ability to use active tone controls to boost or cut frequencies (whereas passive tone controls are really just low-pass filters that can only roll off treble frequencies to make the tone darker). The downside of active pickups is that the tone can cover a wider and flatter frequency range than many players are accustomed to, which some players find too cold or sterile, and the output is generally more consistent, which some players consider less dynamically responsive.

As always (at least when it comes to pickups), there are plenty of exceptions to these general descriptions. Some new active pickup models are designed to provide warm tones similar to vintage passive pickups, and some modern passive pickup designs have expanded treble and bass to provide a wider frequency range without sacrificing dynamic response.

OUTPUT
Now that we’ve discussed most of the popular different types of electric guitar pickups, let’s get into the basic details of pickup construction and specs that guitarists should know. In discussions, reviews, recommendations and sales literature for pickups, the topic of output seems to dominate. Pickups are often categorized as low-, medium- or high-output, and the term “vintage output” gets thrown around a lot, usually for low- or sometimes medium-output pickups.

This all seems relatively self-explanatory, but confusion often arises when getting into specific ways of measuring output, particularly since the biggest pickup companies use different means for listing these specs. Seymour Duncan uses DC resistance, which is measured in ohms, while DiMarzio measures output in millivolts. Some companies prefer to specify inductance (measured in henries) or even a combination of two to all three of the previous.

DC resistance is the easiest spec to measure as it involves little more than using a multimeter set to measure 20k ohms (. ) and connecting the meter’s red probe to the pickup’s hot wire (usually white or red) and the meter’s black probe to ground (either the base plate, braided shielding or ground wire, which is usually black). Actually it doesn’t really matter if you swap the multimeter’s red and black probes as the reading will be the same, but I think it’s good to maintain a consistent approach as a matter of habit.

General DC resistance ranges for Strat and Tele pickups are typically between 6k and 8k ohms, while some lipstick tube single coils have DC resistance around 3-4k ohms and vintage PAF-style humbuckers measure between 8–10k ohms. Modern high-output pickups often measure at least 12k ohms to values above 20k. But while DC resistance provides a good “ballpark” estimate of a pickup’s output, it doesn’t tell the whole story as resistance is influenced by several factors like the total amount of windings, the gauge of the coil wire and magnet strength. One effective description I’ve read compares DC resistance output specs to determining a person’s size only by measuring their height. That may give you a general impression of their size, but is a 120-pound person who is six feet tall really bigger than a 250-pound person who is only five feet tall?

So why don’t most other companies use millivolts like DiMarzio does? The problem there lies with the numerous variables involved in measuring output this way. Essentially, one needs a very controlled environment where, at the very least, the same type of string at the same tension placed the same distance from the pickup is playing the same note struck at the same strength, and so on. Millivolt specs are good for comparing different models offered by the same company, but comparing pickups between different companies is not useful as the standards are not consistent. Like DC resistance, output millivolts are really only helpful for a ballpark estimate.

I could confuse you even further by discussing inductance (which is measured in henries), but since so few companies list this spec, I’ll just skip it for this article. Long story short: don’t worry too much about pickup output descriptions and specs. Depending on the tone you desire, a low-output pickup can be as good of a choice as a high-output pickup. High-output pickups became popular in the Seventies as a quick and dirty means to push an amp into more saturated distortion, but now that most amps have high-gain preamps and any number of overdrive and distortion devices are readily available, the distinction has become less important.

EQ
This Spec is much more helpful in the grand scheme of things than output. Do you want a warmer sound from your guitar? Then you’ll probably want to consider a pickup that emphasizes midrange and bass. How about more clarity, presence and cut? A pickup with boosted treble frequenices may be an ideal choice. Most manufacturers’ EQ descriptions are pretty accurate and many of their websites include recorded examples that provide excellent reference standards, but keep in mind that the new pickups installed in your personal guitar may not match the tone of the guitar in a soundbite due to different tone woods, scale lengths and other construction details, as well as the variations that exist even in two different guitars of the same model.

As a rule of thumb, I find it’s best to try to achieve some sort of balance between the guitar and pickup’s tonal character. If you think that your guitar with its current pickup configuration sounds too dark, look for brighter-sounding pickups and perhaps even consider low- or medium-output models. If it’s too trebly, weak and thin-sounding, go for high-output pickups with boosted midrange and bass.

MAGNETS
While several details of a pickup’s construction affect its tonal character and output, the type of magnet(s) that it uses can tell you a lot about its character right off the bat. The most common types of magnets used for pickup construction are alnico and ceramic. Alnico is short for aluminum, nickel and cobalt, and alnico magnets are usually an alloy of iron, aluminum, nickel, cobalt and copper, and sometimes titanium as well.

Alnico magnets can be made in a variety of different compositions with each element in different percentages, which are graded as alnico 1, 2, 3, 4, 5 and so on (an alnico 3 magnet actually has no cobalt, while alnico 8 and above magnets have a small percentage of titanium). With the exception of alnico 3, a higher number corresponds with a stronger magnet. The most common magnets for guitar pickups are alnico 2 and 5. Ceramic magnets are made from barium, strontium and lead-iron oxides, which results in a stronger magnet that also is cheaper to produce.

While a pickup’s overall tonal character is influenced by many different factors, in general terms, weaker magnets like alnico 2 tend to emphasize midrange while stronger magnets like alnico 5 have more of a “scooped mid” personality with extended bass and treble response. Ceramic magnets usually produce brilliant treble and crisp, articulate attack.

Other magnets used less often for pickup construction include samarium cobalt (featured in Fender’s discontinued Samarium Cobalt Noiseless pickups) and neodymium (featured in Q-Tuner pickups). Both are “rare earth” magnets that are generally stronger than alnico and ceramic magnets but also more expensive to produce due to the higher cost of the raw materials. Another uncommon magnet is rubber ferrite (similar to the magnets most of us use to affix our kids’ artwork to the refrigerator), which is used in most “gold foil” pickup designs.

WINDINGS
Most pick up manufacturers will not reveal the specifics of how their various pickup models are wound because this is where the true art of pickup design comes into play. Dozens of variables are involved here including the gauge/thickness of the copper wire used, the thickness of the wire insulation (which affects how close the metal of the wound wires are to each other), how tight or loose the coils are wound, how many total windings are used, the pattern of the windings, the width and depth of the windings and much more. However, you don’t need to be concerned about these details unless you plan on winding your own pickups one day. Again, a pickup maker’s EQ charts are more helpful in the long run.


Seymour Duncan Dave Mustane pickups

One detail to consider, however, is whether a pickup is potted (the windings coated in wax, epoxy or other material) or not. Coil windings, particularly if the wind is loose, can vibrate against each other when a guitar is played at loud volumes, which can result in a piercing, nasty feedback squeal.

However, at lower volumes loose windings can produce “microphonic” tones that, simply put, deliver a natural, acoustic-like sound similar to using a microphone. Light potting is an ideal compromise, providing some acoustic-like resonance while resisting squeal. Heavy potting is best for guitarists who play at excessively loud volume levels, but some players think the overall tone of heavily potted pickups is too tight and focused.


Fishman Fluence Humbuckers for seven- and eight-string guitars

Then there is the entirely new design of the Fishman Fluence pickups, which replaces copper wire coils with an innovation called the Fluence Core, consisting of two multi-interconnected- layer boards. This design provides two entirely different tones (such as active/passive) at the flick of a switch. Another relatively new innovation is Lace’s Alumitone pickups, which feature “current driven” passive technology that enables a design with minimal coil windings and low DC resistance to produce increased output levels with the expanded frequency response and low noise of active designs.

Pages

Narcotic Wasteland Premiere "Faces of Meth" Guitar Playthrough