Focus plates, are a bit of a weird part really – they simply don’t turn up very often on “off the peg” guitars, and they’re actually pretty rare on after market pickups too – which we always think is quite strange considering they offer up a “tonal variable” to single coils, which, lets be honest, are a little limited when it comes to customisability!
The principle is bordering a little on the “black magic” side of pickups – but its one that’s been around since the year dot on the Telecaster® - with the bridge pickup on the very first models sporting metal base plates. Basically – the base helps “attenuate” the signal being produced by the pickup in some way or another – most people agree that it’s the eddy currents coming off the magnets (even though Brass and Nickel are non ferrous) – either way, it certainly does make a difference.
As a rough guide, Nickel is “clean”, and has very little effect on the frequencies a pickup produces, but can make subtle differences. Brass is great for sucking out a lot of the top end, which makes it brilliant for using on bridge single coils, and copper plates steel seems to bring out a little more mid range, by essentially weakening the magnets whilst in contact.
In conclusion, if you’re looking to tame an overly lively set of single coils, or your building something a bit off the wall – focus plates are a fantastic way of getting different tones, for very little effort. Fender®, Squier®, Stratocaster®, Strat®, Telecaster® and Tele® are registered trademarks of Fender Musical Instruments Corporation and Axesrus ® has no affiliation with FMIC