P156
PICKUP
One of the distinctive features of the Stratocaster pickup is that it is supported at two points, one at each end of the bobbin, as well as the way it is mounted. Interestingly, its size falls almost exactly between that of a Telecaster neck pickup and a Precision Bass pickup.
The bobbin construction, consisting of two pieces of fiber material with the magnets passing through them, is another example of Leo Fender’s distinctive design approach, also found on other Fender models. The major difference is in the mounting method. While the pickups on the other two models are mounted directly to the body with wood screws, the Stratocaster pickups are suspended from the pickguard.
This arrangement resulted naturally from using the pickguard as an assembly plate carrying the pickups and controls. As a consequence, however, the effect of the pickup’s mass on the guitar’s vibrating system differs from that of a pickup mounted directly to the body, significantly affecting the resulting tone.
The insulation used on the magnet wire was also different. Rather than the enamel wire used for the Telecaster and Precision Bass pickups, the Stratocaster used Formvar-insulated wire, another major factor affecting tone through its influence on interwinding capacitance. The number of turns in the coil was also distinctive.
The Stratocaster was also ahead of Fender’s other models in adopting individually staggered magnet heights for the strings and plastic pickup covers. On the earliest 1954 version, the magnet for the third string was slightly lower, but in 1955 it was raised to the same height as that of the fourth string. Early pickups were also treated with black wax to help prevent microphonic feedback and influence or moisture, as was the Telecaster bridge pickup.
TOP VIEW
A typical Stratocaster pickup from the late 1950s to early 1960s. The magnets are of the type known as staggered poles, with their heights varied according to the individual strings. Two eyelets serve as terminals, where the coil wire and lead wires are soldered.
BOTTOM VIEW
On the bottom of the bobbin, the ends of the magnets are flush. The lead wires are the type commonly known as cloth wire, using a fabric-like insulation material with excellent heat resistance.
① 1954
On the 1954 version, the magnet for the third string is lower than that for the fourth string. As a result, the volume balance among the individual strings differs from that of pickups from later periods.
② 1955–’70s
From 1955 onward, the magnet for the third string was raised to the same height as that for the fourth string. This specification continued until the mid-1970s.
③ 1965–
Beginning in 1965, the bottom fiber plate of the bobbin was changed to gray in color. This is the type commonly known as the “gray bobbin.”
PICKUP WINDING
One of Fender’s manufacturing principles was to produce as many components as possible in-house. Pickups were no exception, and were made virtually from the raw materials up.
Abigail Ybarra, shown in the photograph, joined Fender in 1956 and worked winding pickups under Leo Fender’s supervision. At the time of this interview in 1997, she was still an active expert in the field. According to Ybarra, Leo’s instructions were extremely detailed, reflecting his determination to achieve the highest possible standards in both durability and sound quality.
The pickup winders used at Fender at the time were designed by Leo and built in-house. They were powered by sewing-machine motors with foot-pedal speed controls. The bobbin was mounted horizontally on a shaft, but rather than being driven directly, it was rotated by a belt-drive system. This was designed to prevent excessive wire tension from becoming concentrated at the ends of the bobbin. Ybarra recalled that, in searching for the softest possible drive material, Fender ended up using nothing more sophisticated than an ordinary rubber band as the drive belt.
The early Fender winding machines had no mechanism for controlling either wire feed or tension. Instead, according to Ybarra, the operator held the wire between the thumb and index finger of the right hand, simultaneously controlling both the feed and the tension.
Leo gave particularly detailed instructions concerning the way the coil wire was laid down. Rather than winding it in tightly packed layers, he wanted adjacent layers of wire to be kept as separated as possible. His concern was to minimize interwinding capacitance, which he believed would otherwise reduce the extreme high-frequency content responsible for definition and clarity in the sound.
Once the coil had been wound and the lead wires attached, the entire bobbin was immersed in wax for impregnation as a measure against microphonic feedback. Leo also believed that this treatment would drive out even the minute amounts of moisture contained in the fiber material and other components, moisture that could contribute to deterioration of the pickup over time.