Guitar Pickups – What You Need to Know
By Anderton |
Guitar Pickups – What You Need to Know
Looking for a good pickup line?
by Craig Anderton
They’re just wire and magnets, right? Well…yes, but there’s a lot more to the story than that. A pickup change can give an entirely different sound and vibe, but you need to understand what goes into making pickups so you can choose the right solution for the sound you want.
So, let’s examine what makes a pickup a pickup, and what these various elements mean to you.
MAGNETS AND TONE
Pickups with Alnico II magnets strike a balance between warmth and brightness. Their “vintage” sound has a sweet midrange, without high frequency brittleness. Alnico II was used in the original PAF pickups, which are best known for a smooth, “singing” tone when overdriven.
Gibson's Burstbucker pickups use Alnico V magnets, which give a more "aggressive" sound than the "sweeter" Alnico II magnets used in PAF-type pickups.
Alnico V magnets are stronger and have both more bass and treble than Alnico II types. This gives a somewhat edgier, more aggressive tone associated with metal and hard rock, as well as more clarity with high-gain amps.
Ceramic magnets are generally the strongest magnet type, which leads to brighter pickups with a tight, instead of warm, low end. They retain clarity and articulation even with heavy distortion, and typically have high output levels. They are also less expensive to manufacture than metallic magnets. Most guitarists consider ceramic magnets less suitable for clean tones than Alnico magnets.
Some pickups are “hotter” than others. A hotter output will drive tube amps and some pedal inputs harder, thus giving more potential overdrive. Output levels are less relevant with amps, effects, and audio interfaces that have their own input gain controls.
HUMBUCKER VS. SINGLE-COIL
Humbucker pickups are known not just for their resistance to hum, but their warm, beefy sound. Single-coil pickups (so called because humbuckers have two pickup coils) have a bright, somewhat “glassier” sound and are more susceptible to hum.
All Gibson pickups except the P90 are humbucker types. (Although the P90 is technically a single-coil pickup, it is more resistant to hum and has a fatter, more aggressive sound than conventional single-coil types.)
The Mini-Humbucker has an interesting background - it was made specifically for guitarists who wanted to replace P90 single-coil pickups, which are smaller than standard humbuckers, with a pickup that had humbucking properties.
However, by switching out one of the coils, a humbucker can give a single-coil sound. Guitars often include knobs with a switch that can change the humbucker sound to a single-coil sound. If a pickup is specified as using a “four-conductor cable,” that means that each coil can be wired separately, thus allowing for coil splitting. A humbucker with two-conductor cable means that you can’t convert it into a humbucker without breaking the connection between the two coils—doable for solderheads, but not necessarily fun.
While researching this article (translation: talking to people who know more about this stuff than I do), I found out several interesting aspects of Gibson pickups that relate to the coils used in humbuckers.
The Gibson 490 pickup is available in the "zebra" color scheme that first appeared in the 60s. Note the four-conductor cable that allows the coils to be split for more of a single-coil sound.
First, consider the “zebra” look where a pickup has one black and one cream-colored bobbin. There is no sonic significance to this; one day back in the 60s the Gibson factory ran low on black bobbins, and because the pickups had covers and the company figured no one would see the bobbins or care, they just alternated cream-colored ones with the black ones.
Another is that back in the day, the pickup winding machines weren’t exactly precision devices, so sometimes coils would have more or less turns than others. This is why some people found particular pickups, even if they were the same model (in theory), to have “magical” properties.
Gibson analyzed these and found that pickups people liked for being “hotter” were overwound (i.e., had more turns) compared to other pickups.
The top coil is the “screws” coil, and the bottom oil is the “slugs” coil. The tape wrapped around the coils helps protect them, especially if you’re not using pickup covers.
Also, if the coil surrounding the pole piece screws has fewer windings than the coil surrounding the slug, the pickup will more of a single-coil sound. So to get a balanced sound, it’s actually necessary to overwind the screws coil so that neither coil dominates.
GOING TO POT
One problem with early pickups was microphonic response, where sound from an amp would interact with the pickup’s windings to cause “squeals.” Potting the pickup with wax to fill in all the air gaps helps to minimize any kind of microphonic interaction.
DC resistance is a common pickup specification that correlates to the number of windings in a pickup coil. This affects output and frequency response somewhat, with higher resistances in theory meaning a little higher output and a slightly duller sound. However, in practice most DC resistance comparisons are meaningless because pickups use different manufacturing techniques that make much more of a difference than DC resistance. Where DC resistance does matter is with two pickups that are identical in all other aspect except the coil windings.
PICKUP AND STRING INTERACTION
Let’s close with the age-old question: How far should pickups be from the strings? Although the conventional wisdom is “closer to pickups = more level, further from pickups = less level,” there’s much more to the story than that…and there’s an entire article on the subject right here on Harmony Central, so check it out for the complete rundown.
Pickups remain controversial, because they’re actually pretty complicated critters from a physics standpoint so they’re quite nuanced. Hopefully we’ve covered the important info that can help you better understand what pickups are all about.
Note: All photos are courtesy Gibson Brands and used with permission.
Craig Anderton is Editorial Director of Harmony Central. He has played on, mixed, or produced over 20 major label releases (as well as mastered over a hundred tracks for various musicians), and written over a thousand articles for magazines like Guitar Player, Keyboard, Sound on Sound (UK), and Sound + Recording (Germany). He has also lectured on technology and the arts in 38 states, 10 countries, and three languages.