P-90

Around 1940 Gibson offered a new bridge pickup for ES-100/125 series, as an alternative to the classic Charlie Christian pickup, cased in metal.

Officially, P-90 pickups were introduced in 1946, when Gibson resumed guitar production after World War 2. They were initially used to replace Gibson's original "bar" or "blade" pickup, also known as the Charlie Christian pickup, on models such as the ES-150, and by the end of the 1940s it was the standard pickup on all models.

The P-90's reign as the Gibson standard pickup was short-lived, as a new design of pickup, the humbucker, was introduced in 1957. Equipped with double coils, the new pickup boasted greater output and less hum, although with less high end response. This new pickup, occasionally named PAF, very quickly took over as the preferred choice for all Gibson models, relegating the P-90 to budget models such as the ES-330, the Les Paul Junior and Special, and the SG Junior and Special, such as those used by Pete Townshend and Carlos Santana. This trend continued throughout the 1960s and particularly in the early 1970s, where the P-90 all but disappeared from the entire Gibson range. By the 1970s, smaller single-coil pickups, mini-humbucking pickups, and uncovered humbucking pickups began replacing the P-90 pickups on Gibson's budget and lower-end models.

In 1968, Gibson reissued the original, single-cutaway Les Paul, one version being a Goldtop with P-90 pickups. In 1972, they produced Limited Edition reissues, called the "58 Reissue" though actually based on the 54 Goldtop Les Paul, with a stopbar tailpiece; and the 54 Custom, the "Black Beauty," equipped with a P-90 in the bridge and an Alnico 5 pickup at the neck. Total production of these guitars was quite small. In 1974, Gibson put the P-90 pickup in their Les Paul '55, a reissue of the Les Paul Special from that era. It was followed in 1976 by the Les Paul Special double-cutaway (DC) model and in 1978 by the Les Paul Pro (which had an ebony fingerboard with trapezoid inlays). Since the 1970s, the P-90 pickup has seen some success in various models in the Gibson line, mostly through reissues and custom versions of existing models. Currently it is featured most prominently on the Les Paul Faded Doublecut, and certain models in the Historic range.

In the early 1970s, punk rock guitarists such as Johnny Thunders of The New York Dolls began using Les Paul Juniors and Les Paul Specials equipped with P-90s because of the cutting overdriven sound and the inexpensive nature of the guitars. In both The Dolls and The Heartbreakers, Thunders influenced younger punk rock guitarists who adopted his look and choice of guitar. Mick Jones of The Clash and Steve Jones of The Sex Pistols both owned Les Paul Juniors, and the double-cutaway Junior became the first choice for punk rock guitarists.

The P-90 was also marketed by Gibson in the 1970s as the "Laid Back" pickup, as part of a line of "named" pickups.[1]

For the 2014 model year, the Les Paul Melody Maker featured a variant of the P-90 pickup called the P-90S, inspired by the original pickup of the Gibson ES-125. This variant possesses six rectangular Alnico-slug pole pieces with no individual height adjustment.

There are three major varieties of P-90 casing:

Gibson P-90 soap bar

• Soap bar casing has a rectangular shape and the mounting screws are contained within the coil perimeter, positioned between the pole pieces, between the second and third strings and between the fourth and fifth strings, thus creating an irregular and somewhat unusual pattern. Occasionally they are mistaken for pole pieces, thus sometimes the P-90 is erroneously said to have eight pole pieces. The soap bar nickname most probably comes from its shape and proportions, and that the first P-90s on the original Gibson Les Paul Model of 1952 were white.

P-90 dog ear

• Dog ear is a casing type with extensions at both sides of pickup. These are extensions that hold the mounting screws. Dog-ear P-90 pickups were commonly mounted on Gibson's hollow-body guitars like the ES-330 and occasionally on solid-body models like the Les Paul Junior. The same pickups were also available on Epiphone models (since Gibson was building Epiphone guitars in the 1950s) and the design is best remembered for its appearance on the hollow body Epiphone Casino of the mid to late 1960s.

• Humbucker Casing To install a P-90 in a guitar routed for humbucker pickups (a Les Paul Standard for example), the installer must modify the existing rout in the body. This may result in aesthetic issues, due to gaps between the body and hardware, or even structural problems, as is the case when re-routing the neck humbucker opening on a Gibson SG guitar. Because of this, pseudo P-90s in a humbucker-sized casing are common (see below).

Being a single-coil design, the tone of a P-90 is somewhat brighter than a humbucker, though not quite as crisp and snappy as Fender's single-coil pickups. The tone therefore shares some of the single coil twang, but having large amounts of midrange and often described as “thick". The reason behind the tonal difference between P-90s and Fender single-coil pickups is due to construction methods. P-90s use bar magnets set under the polepieces, much like a humbucker, whereas Fender single-coils use rod magnets as the polepieces. Popular guitars that use or have the option of using P-90s are the Gibson SG, Gibson Les Paul, Ernie Ball Axis series and the Epiphone Casino. Fender Jazzmaster pickups are often confused with the P-90; however, their only similarity is cosmetic, since there are many significant visual, dimensional and electrical differences.

All Gibson P-90 pickups (vintage and otherwise) were machine wound on Leesona coil winding machines, although their electrical specifications may vary slightly due to operator error. In common with many other modern pickup types, there are two versions of modern P-90: neck and bridge version. Their DC resistance tends to be around 7–8 kΩ for neck pickups and 8–9 kΩ for bridge pickups. Early P-90 pickups made before approx 1974 were manufactured with no difference in the bridge and neck position and were interchangeable. After winding, pickups were hung on a rack holding 20 pickups and assembled according to the model of guitar they were to be used on (Soap-Bar or Dog Ear). Earlier pickups (around 1952) had Alnico 3 magnets, but in 1957 Gibson switched to Alnico 5.

P-90 Soapbar-3, made by Seymour Duncan

One negative aspect of the P-90 pickup is its susceptibility to 50 Hz / 60 Hz mains hum induced in its coil by external electromagnetic fields originating in mains-powered electrical appliances, motors, lighting ballasts and transformers, etc. This susceptibility is common to all single-coil pickup designs, but the P-90, having around 2,000 more turns of wire in its coil than Fender pickups, receives a relatively large amount of mains hum. Several manufacturers now make hum-canceling pickups that resemble the P-90 but most do not have a similar sound.

There are three types of hum canceling pickups that can fit inside a Soapbar P-90 cover:

• First generation Stacks (vertically stacked coils) such as Gibson’s P-100 and Seymour Duncan Stacks. These invariably require a deep pickup cavity.
• Sidewinders (1955 designed horizontal side-by-side coils) such as those produced by Gibson, Lace, Fralin and Mojotone. These compact examples install into standard pickup cavities.
• New generation buffered vertical humbuckers from Kinman P-90 Hx (Patented). The Gen-3 versions also install into standard pickup cavities.

First generation hum-canceling Stacks such as Gibson P-100 and Seymour Duncan Stacks have two coils arranged to give the Humbucker effect, meaning there is a second identical coil below the main one and they share two bar magnets in common. Hum is effectively cancelled since the coils are connected out of phase. However, as with all crude Stacks there is a large degree of magnetic coupling between the coils which cancels string signal right along with the hum. Manufacturers over-wind the coils to recover the output loss, but this introduces a second problem: excessive coil capacitance that robs the sound of dynamics, presence, and touch sensitivity. Despite contrary marketing claims these two design flaws/issues gave these types of pickups a bad reputation among musicians.

The Sidewinder, otherwise known as a "Center or Middle Point Humbucker" since there are two side-by-side coils and the six pole screws are positioned between the coils. The Sidewinder is the product of Heuristic (engineering) and originated by Gibson in the mid-1950’s. Now days it is used as an attempt to overcome the drawbacks of the crude stacked design and because it's compact size conveniently does not require pickup cavities to be deepened, unlike crude Stacks which are far deeper. It does this with both coils reoriented from vertical to horizontal configuration but using a similar magnetic circuit to that of a P-90. Unlike stacked coils where common-mode string signals are canceled thereby reducing output level, output of Sidewinders is slightly better. Unfortunately, unlike a side-by-side humbucker, due to electro-magnetic shortcomings of the Sidewinder design a great loss of mutual inductance between the two coils exists which ostensibly means one coil produces most of the string signal output while the second coil is present just to cancel hum. This means over-winding with finer wire is still necessary to attain sufficient output and the maker faces a precarious balancing act of achieving sufficient output and avoiding excessive coil capacitance and thus Sidewinders generally can not match the high output of a regular P-90. Sonically, sidewinders sit somewhere between a regular P-90 and a stacked pickup. When played clean, they don't chime and they aren’t lush like a single coil P-90, but they aren't nasal or completely lifeless either. The Sidewinder finds a place in over-driven sounds where a loss of sparkle and dynamics is less important than avoiding amplifying hum. These type of pickups, when put in a Soapbar cover, have the same outward appearance of P-90s but the insides are very different.

Examples of Sidewinders are Lace Holy Grail, Lindy Fralin, Gibson P-90H and the Quiet Coil by Mojotone, and although the magnets and magnet wire found in regular P-90s are present in the Quiet Coil, unlike a real P-90 which has a single coil, there are two coils. Mojotone claim their Quiet Coils attempt to match the inductance and resonant peak frequency of a true single coil P-90 but without the hum. However that is an objective of all competing Sidewinder P-90 pickups. The Sidewinder design allows less deviation from P-90 sound than crude Stacks. All Sidewinders avoid the need to modify the guitar with extra routing of the pickup cavity, unlike common Stacks and is a strong reason for the sudden explosion of Sidewinder pickups appearing in the market place circa 2018.

The 3rd generation Zero-Hum P-90 Hx patented by Chris Kinman, main man at Kinman Guitar Electrix, was released in 2021 and is the only hum-canceling design that produces the string signal in a buffered singular coil, thus it achieves authentic P-90 sound and appearance and does not suffer from the same design limitations that plague Sidewinders. Having taken 9 years to develop and perfect, the Kinman P-90 Hx is not a product of Heuristic (engineering), it appears to be properly designed pickup that can be somewhat likened to a Stack, but unlike crude Stacks there is no sonically destructive magnetic coupling between the upper and lower coils which is avoided by highly efficient dual magnetic shields around the upper single coil. The upper coil produces string signal and hum while the lower coil produces ONLY hum, thus avoiding common-mode string signal cancelation, thus it is known as a hum-sensor. It is wound in a coil gap of just 3mm with far fewer turns of thicker wire than the upper string sensor into a unique and highly efficient laminated steel bobbin for minimal turns count and consequent very low capacitance despite the astonishing 1200 millivolt hum output it achieves. The entire hum-sensing bobbin is just 5mm in height. This radical hum sensor results in desirable transparency and consequent minimal destructive impact on string signal. Kinman advertise their P-90 Hx as having a Patented 600-Ohm hum sensor and producing stellar highs, lush P-90 lows and typical P-90 growl. Twelve years after the introduction of the P-90 Hx, in 2021 came the latest version known by the model extension "Gen-3 v2" which, with the entire hum sensor at 5mm in height, is 4mm shorter than the previous Gen-2 hum sensor which had a height of 9mm. Thus the Gen-3 v2 models which are lighter and shorter do not require most pickup cavities to be deepened.

Although the P-90 Hx is a very complex and highly sophisticated pickup that costs in the vicinity of 5 times that of a Sidewinder to manufacture, Kinman perseveres with it with the knowledge that not a single competitor would be interested in copying it. Kinman's thinking proved to be correct and the P-90 Hx stands alone as the highest performing Zero Hum P-90 in existence. Kinman also makes a hum-canceling P90-Bucker which is in a metal humbucker cover and is interchangeable with regular humbuckers. It is advertised as having a very dynamic sound that has a lush feel and very good trebles and the low strings growl like a real P-90.

'There is a fourth type of pickup sometimes found under a P-90 Soapbar cover, it is known as a mini-humbucker. These, however, are not intended to mimic the sound of a P-90, although Kinman's "Mini P90-Bucker" comes very close. Like all side-by-side humbuckers, they have much lower hum levels. This configuration operates in the same way as a humbucker: both coils respond to string vibrations, but since the two coils have a reversed magnetic polarity, the signal from both coils is summed, while the hum is effectively canceled. Most brands of these pickups sound more like a humbucker than a P-90.

Around 1970, Gibson replaced the P-90 on several models with a downsized side-by-sided mini-humbucker. This pickup was originally used on Epiphone models such as the Sheraton and with suitable Soapbar mounting shrouds became interchangeable with the P-90. In later years, in response to a resurgence of popularity of the P-90, Gibson issued the P-100, a flawed, stacked, hum canceling version of the P-90 (see above). Gibson also made a newer noiseless P-90 called the H-90, which is found in Billie Joe Armstrong's Signature Les Paul Junior. The H-90 has two crudely stacked coils and Gibson erroneously claimed that it does not lose the sonic and feel characteristics of a P-90, however many players disagree, perhaps contributing to its lack of favor and use in other guitars.

• Electric guitar pickup analysis results, a massive load of data on various pickup models, obtained in UIUC Physics 406 "Physics of Music" course.

• All About P-90s