I equate a more compact coil with a crisper treble response in the low-end, which gives a slightly harder tone.” “The P-90’s character also changes depending on which winding machine was used because of the differences in coil tightness. It becomes much more consistent when they go to poly-coated wire around ’65 to ’66, but the poly wire really changes the character of the sound. You see random differences in the ohms per foot of the wire and the 42-gauge diameter tolerance. You can find outliers above and below, but throughout the 50s they’re generally not as hot as later ones.
P-90s most often vary between 7.2k and 8.1k. The general consensus is 10,000 turns, but that varies depending on the era and it’s not unusual to find P-90s well under 10,000 turns. “In the 50s, Gibson used the same 42-gauge plain enamel wire you find in PAFs. The shorter magnets generally sound a little more aggressive than the longer equivalent Alnico magnets. By 1960, you often see them with shorter magnets, and by ’61, they became standard. I’ve seen a pattern of Alnico IV being used for bridge pickups and Alnico II being used for neck pickups, but like many things with vintage guitars, they weren’t consistent about it. “After that, they mainly used Alnico IV, V and II. The general consensus is 10,000 turns, but that varies depending on the era and it’s not unusual to find P-90s well under 10,000 turns They appear randomly during ’52, and you can also find some from ’53. “As far as the magnets go, P-90s generally have the same 1/8-inch thick magnets that you see in PAFs, but there was a very small window where they used a thicker Alnico III magnet. (Image credit: Future) Magnetic personality It’s a Geo Stevens machine made in 1950, so that’s probably a reliable timeline as to when the P-90’s design was finalised. We make every single part of the pickup assembly here in the USA, and for some of our P-90s, we use one of the original machines with the original fixtures that Gibson used. Those changes inevitably affected the sound, so what I try to do is recreate those variations and elements of the 50s and 60s from ’52 onward. “The initial design appealed to people for good reason,” Jon tells us, “and that design evolved over time because of Gibson’s desire to improve efficiency and I think that’s what drove the evolution of. Hoping to arm our readers with some down-to-earth knowledge by shedding some light on the evolution of the P-90 throughout Gibson’s golden era of the 50s and 60s, we spoke to Jon Gundry, founder of Michigan’s preeminent P-90/PAF repro specialists, ThroBak, located in Grand Rapids, some 50 miles north of Gibson’s old Kalamazoo site. As such, over the years, guitarists have increasingly turned to period-correct repro P-90s and sought out original examples from the earlier periods of Gibson production for a piece of that elusive vintage magic. Although its basic construction remains the same, having been in production for well over seven decades, the P-90 has seen many changes with respect to manufacturing techniques and materials - changes that, to many people’s ears, significantly affect both the pickup’s sound and appearance.