Fig. 2 — Photo by Dan Formosa
Pickup Pole Pieces
A typical pickup may contain six individual magnet poles (often referred to as pole pieces). Or it may contain six steel poles that have become magnetized as a result of their proximity to a magnet lying within the pickup. Dissect some pickups and you will encounter variations on these basic themes, such as a steel blade that runs across the pickup beneath the strings.
Using magnets for poles and wrapping a coil around them is the most straightforward method of making a pickup, but this concept has a few limitations. If a magnet could be easily machined, pickup manufacturers would just turn them into screws to allow easy height adjustment. But they can’t. Or, more accurately, it has been tried, but abandoned.
Therefore on a typical Stratocaster or Telecaster pickup, the individual magnet poles are not adjustable. The pickup may come from the factory with all poles set at an even height, or the heights may be staggered to anticipate the preferred string balance, as shown in Fig. 2. But the only way to adjust a pole on a traditional Fender pickup is to raise all of them at once by raising the pickup itself.
Harry DeArmond solved this problem with the DeArmond 2000 (aka Dynasonic), a pickup that employed a rather complex mechanism. Six small slotted screws, visible from the top, connect to adjoining magnetic poles, secured from within by teardrop-shaped brass rings (Fig. 3). Each pole has a spring that allows it to move up and down, so you can turn the screw to adjusts the pole height. Gibson’s “staple” pickup, developed circa 1954, follows a similar model.
Fig. 3 — Photo by Dan Formosa
Why bother staggering the pole heights? It’s simple: Different string types and gauges will perform differently. Your 2nd string will have approximately 50 percent more metal reacting with the pickup than your 1st string. An unwound 3rd string will have approximately three times as much. And although the amount of steel will be a contributing factor, it’s not the whole story. A .016 plain 3rd string isn’t going to vibrate the same way a .009 1st string vibrates. To ensure good string-to-string balance, it’s helpful to have height-adjustable poles.
Fig. 4 — Photo by Dan Formosa
DeArmond’s adjustable mechanism is beautifully intricate, but there’s an alternative solution: use steel screws. Designing a pickup so that portions of the steel screws are near a magnet allows the screws to act as magnets that can easily be individually adjusted. Problem solved. Fig. 4 shows a single-coil P-90 pickup with two bar magnets and adjustable steel screws for poles. This design was patented by Charles F. Shultz in 1959.
In the early days of electric guitar, adjustable poles were more of a necessity than they are now. As pickup maker Curtis Novak points out, strings made today are much better balanced than strings were in the past, so worry not—you and your pickups with non-adjustable-poles should get along just fine.
When tinkering with adjustable poles, don’t simply set them to be as high as possible. Raising a pole means you are placing its magnetic field up closer to a string. Any perceived improvement obtained by bringing a pole closer to a string may be offset by a decrease in sustain as the magnetic pull dampens the string’s vibration. It’s well worth spending time to experiment with different pickup and pole heights. Many guitar manufacturers and pickup makers offer charts showing optimal spacing between pickup pole pieces and their corresponding strings. This information is based on a lot of testing and research, so it’s a good idea to at least start with the recommended settings.