Hey fellow guitar tone lovin' Guys n Gals!Ready to jump into a hot topic ... err, literally, like a hot vat of wax? Let's talk about wax-potting pickups, and what it does. Sound downright exciting? If so, then yep ... you are a certified guitar-tone connoisseur! Let's "jump in" :)
First the history, if you've read my blogs much, you know I LOVE the history behind all these little guitar tone innovations. When the world was dark, and yet without shape and form ... okay, I'm going a bit toooo far back ... let's travel to the late 1940's/early 1950's; at that time electric guitars were just taking off, and the first electro-magnetic transducers (pickups) had just been designed by Leo Fender and Seth Lover at Gibson. They both involved spinning nearly a mile of ultra-thin wire around a magnetic field to transform the movement of the strings into an electric signal that could be amplified. These first designs, the Broadcaster, and P-90 respectively, did a mighty fine job, and happiness reigned throughout the land. Then came the Stratocaster pickups, and the first "Humbucking" pickups from Gibson. And the world became even happier! That is until the guitar playing world discovered high-gain, fuzz, distortion, and the like; with the addition of all this "distortion", which both the folks at Fender as well as Gibson thought NOBODY would ever want, guitars started to feed back and squeal like a son of a gun, kinda out of control and impossible to handle.
Something had to be done!
Enter wax-potting. Now I watched an interview with Eddie Van Halen where HE claimed to have invented wax-potting all on his own, but I think his memory failed him a bit, because I know for a fact it was the mind of Seymour Duncan that devised the idea of bathing pickups in wax, heated to the point of becoming liquid. The wax bath held all the little turns of ferry-hair fine wire together, so they wouldn't sympathetically resonate (feed back) so easily. And, I DO believe Edward was one of the very first to use these wax-potted pickups.
So then, potting is a GOOD thing?
Well, yes... and no. wax potting definitely allows you to play louder with more gain before the guitar begins to feed back uncontrollably. But there IS a down-side: Wax potting also reduces the complex harmonics and touch-sensitivity of the pickup. A short bath in the wax doesn't alter the tone much, but a LONG bath makes a pickup downright lifeless and sterile, ugg! About the only way you can really get the potting done properly, so the tone remains unaffected, yet the feed back is controlled, is the way Seymour did it in the good old days: very carefully, by hand, with just the right mix of paraffin and bees-wax mixture, and with experience. It's 50% art, and 50% science to pot a pickup perfectly. Too much and you've got a dead sounding pickup, too little and ya got squeal ... and if the wax is too hot or the mixture wrong you have melted pickup bobbins and maybe even a fire!
So, here is the general rule of thumb:
Vintage (pre 1960) were pretty much ALL un-potted.
1959-1969 were a dicey crap-shoot.
1969 and on, most all pickups were potted.
Cheap Japanese made pickups from the 1970's were never potted.
Most pickups from about 1985 on were mostly OVER-potted, especially humbuckers. (the exception being high-end or historic re-issue guitars)
The thought was that EVERY guitar player was now playing with tons of distortion, so pot the living snot out of the pickups. So if you're in a metal or hard-rock band, that's maybe a good thing. But as of this writing, more and more player are hearing what real-deal un-potted 50's era Gibson and Fender pickups sound like, and by comparison, there modern-day over-potted pickups sound lifeless and dead.
So what's a player to do if he wants to have his cake and eat it too ... have great tone AND feed back under control? The easy answer is to go with pickup makers who still do it the old-fashioned way, hand-potting to perfection. These are generally the boutique makers who's pickups are among the most expensive because, well, they are made by the hands of an expert; not on some generic assembly line in some country where labor is cheap. Oh, and as serious benefit of the boutique builder is YOU can specify the pickups level of potting! Yep, you can choose to have it vintage-style un-potted even.
And I'll leave you with this down-n-dirty video I did showcasing the difference between a vintage un-potted PAF and one of my lightly hand-potted humbuckers. See y'all next time :)