|Manufacturer||Gibson Guitar Corporation|
|Magnet type||1956-1960: Alnico 2, 3, 4, and 5
1961-1975: Alnico 5
|Voltage (RMS), V||127 mV at 7.715 kHz|
|Impedance, kΩ||1956-1961: ~7.5-9.5
A P.A.F. or simply PAF is an early model of the humbucker guitar pickup invented by Seth Lover in 1955. Gibson began use of the PAF on higher-model guitars in late 1956 and stopped in around 1962. They were replaced by the Patent Number (Pat No) pickup, essentially a refined version of the PAF. These were in turn replaced by "T-Top" humbuckers in 1967, and production ended in 1975. Though it is commonly mistaken as the first humbucker pickup, the PAF was the first humbucker to gain widespread use and notoriety. The PAF is an essential tonal characteristic of the now-famous 1958-1960 Gibson Les Paul Standard guitars, and pickups of this type have gained a large following.
In the mid-1950s Gibson looked to create a new guitar pickup different from existing popular single coil designs. Gibson had already developed the Charlie Christian pickup and P-90 in the 1930s and 40s; however, these designs—like competitor Fender's single-coil pickups—were fraught with inherent 60-cycle hum sound interference. Engineer and Gibson employee Seth Lover spent much of 1954 working on a noise-cancelling or "hum-bucking" guitar pickup design. By early 1955, the design was completed. In June 1955, Lover and Gibson filed a joint patent for the pickup design.
Gibson began switching from P-90s to PAFs first on the company's lap steel guitars in 1956, and then on electric guitars in 1957. Les Paul Goldtops and Customs were the first solid-body electric guitars to receive PAF humbuckers, and Gibson's ES Series were the first hollow/semi-hollow designs to receive them.
In late 1957 a black sticker with gold lettering was applied to each pickup's underside, that read "PATENT APPLIED FOR." This name was shortened to "PAF" to create the nickname these pickups have been known by since. US patent 2896491 was eventually issued on July 28, 1959. The popular abbreviation "PAF" as used in guitar pickups is now a registered trademark of DiMarzio.
In 1958 the Goldtop model was dropped from production, and the sunburst Standard took its place. These guitars were all fitted with PAF humbuckers, which contributed greatly to the instruments' sound.
Early 1961 PAFs are almost exactly identical to the original 1957-1960 PAFs. In July 1961 Gibson standardized the PAF construction process with the introduction of the SG model. With this, a new, smaller Alnico 5 magnet became standard. Also, a more formal number of wire winds was introduced, causing pickup DC resistance to center around 7.5kΩ. Around 1963, Gibson switched to polyurethane-coated wire from enamel-coated to cut costs, changing the wire color from purple to red. In addition, these pickups were also given a new sticker that had a patent number written on it. However, the stickers were labelled with "U.S. Patent 2,737,842" until 1962, which is the number issued to the 1952 Les Paul trapeze tailpiece design and not the humbucking pickups. In 1966 Gibson began using automatic pickup winding machines, thus making humbucker pickups with a consistent number of turns and fixed DC resistance.
With the reintroduction of the Les Paul Standard in 1967, Gibson began putting a T-shaped toolmark on humbucker bobbins. This helped workers ensure the bobbin was facing the correct way during assembly. Many original PAF specifications changed in these pickups, such as the use of a plastic spacer instead of a maple spacer and the use of thinner Alnico 5 magnets. These pickups are referred to as "T-tops". Gibson ended production of this iteration of the PAF design in 1975.
In 1981 Gibson realized that there was a consumer demand for the sound of original PAF pickups. Engineer Tim Shaw designed a pickup that aimed to replicate the early design, reversing changes made in the 1960s and 1970s: a new bobbin without the "T", a correct small square hole back in both bobbins, enamel wire, and thicker Alnico magnets. Shaw's efforts are generally considered to be the first of many recreations of the PAF humbucking pickup.
Gibson currently produces several reissues of PAFs including the "'57 Classic" and "Burstbucker".
Early PAFs are often the most-sought-after vintage humbucker pickups by guitarists, and each individual pickup is unique in terms of output level and tone. Factors that account for their sound are:
- Early Gibson pickup winding machines were manually operated and had no mechanism to automatically cut the wire after a set number of turns. Thus every pickup had a different number of windings and that led to variation in the output and tone. For the same reason, the two coils within each pickup unit usually also have a slightly different number of turns
- Gibson used Alnico magnets in PAFs, the same magnet as used in the P-90. Alnico has several different grades and different magnetic properties (grades 2, 3, 4 and 5 are usually used). Gibson assigned them quite randomly until the end of the era of early PAFs. The most common of these was Alnico 4
- Original pickups are now over forty years old and thus their tone may have changed significantly over time. This is due to the slow demagnetization of Alnico magnets and the warping of the plastic bobbins (which changes the placement of the wire)
- US patent 2896491, Seth Lover, "Magnetic pickup for stringed musical instrument", issued 1959-07-28 — PAF pickup itself, hum cancellation
- "Gibson PAF Humbuckers". Vintage Guitar Info. Retrieved 3 January 2015.
- Marx, Wallace (17 December 2009). "The Pickup Story, Part III: The Road to the Humbucker". Premier Guitar. Retrieved 3 January 2015.