How To Adjust (Set) Pickup Height on a P-90 for ULTIMATE TONE!

Wow!  So, this has turned into part four in this series:

• How To Set Pickup Height on a Stratocaster for ULTIMATE STRAT TONE! 
• How To Set Pickup Height on a Telecaster for ULTIMATE TELE TONE!  
• How To Set Pickup Height on a Humbucker for ULTIMATE TONE!

But man, it was brought to my attention that I totally forgot about the lowly old P-90s!  Well, let’s rectify that situation!

Once again, I need to make it clear that these are my personal recommendations.  You may be going for something totally different, and as such may want to totally disregard my suggestions; if so, I fully understand, and rest assured, my feelings will not be hurt in the least bit. 

Okay, now this is important, as far as pickup height is concerned, P-90’s are an entirely different animal from either humbuckers or single-coils.  With a Strat or Tele style single-coil pickup the magnetic field, or the part of the string being sensed by the pickup, is soooo small and, even microscopic changes in pickup height make a perceivable sonic difference. Humbuckers are sensing a much larger portion of the strings movement, and as such are a little more lenient on pickup to string height adjustment.  From nearly as close as the pickup can get without touching the strings to as far away as it can be adjusted, decent tones can be had.

Now a P-90 is an “interesting bird”; tone-wise it’s in the same camp as the early PAF Humbuckers, in fact, the design goal of the first humbuckers was to sound just like a P-90, but without the hum!  But, of course from a physical standpoint, the P-90 is much more akin to a Fender-style single-coil pickup.  However, there are some very important things to keep in mind when setting the height of a P90:

The P-90 IS a single-coil pickup, but that coil is way wider and more shallow than on a Strat or Tele style single-coil;  the P-90 is also wound with a lot more turns of wire ie: it’s a lot fatter and hotter.  As a matter of fact a 1957 P-90 has about the same output as a 1957 PAF.  Result:  Tonally, the P-90 is more like a PAF humbucker than a Strat single-coil.  The narrow coil and (relatively) low output is a big part of the Fender spank ... and the P-90 has neither!

Fender’s designs employed pole-pieces that are the actual MAGNETS, whereas the P-90’s use steel screws/slugs (same as the humbuckers), with magnets on the back-plate wedged up aginst those steel pole-pieces making them somewhat magnetically charged.  This means the Fender pole pieces have a gauss (magnetic pull) of about 3-4 times what a P-90 has.  So again, the result:  Tonally, the P-90 is more like a PAF humbucker than a Strat single-coil.  The strong magnetic pull is a big part of the Fender chime!

And so, setting the height on a P-90 is a lot more like setting a humbucker than it is a Strat/Tele pickup.  Because the magnetic pull is fairly low (in the 300-Gauss range compared to 1100 for a typical Strat pickup), you can get by with placing the pole-screws very close to the strings without worry about it sacrificing string resonance.  Because the coil is so wide and the gauss so low, the P-90 is also quite forgiving placement-wise, although not as much so as a humbucker which has even less pole gauss and more coil(s) width.

One last thing to mention:  P-90’s are an archaic design from the 1940’s; really, they are the oldest pickup designs still in regular use.  As such, they were never really designed to be very adjustable.  In fact the earliest versions (often called the “A-90”) didn’t even have adjustable pole-screws, just fixed steel slugs.  Now, the soap-bar versions generally have a decent amount of height adjustment available … but those old “dog-ear” versions, well … if ya want to make any drastic height adjustments to them, you gotta actually “shim” them.  Yep … archaic!

I prefer to use a digital caliper to take measurements, but a quality luthier’s ruler will do fine if you have excellent vision!  Okay, so with no further ado, here are my suggestions and reasons why.

Bridge pickup

Low E: 2.6mm / 0.10"

Hi E : 2.35mm / 0.092"

Neck Pickup:

Low E: 4.5mm / 0.18"

Hi  E  : 3.43mm / 0.135"

(Measurements from the bottom of the string to the top of the magnetic pole piece screws)

Yep … that’s CLOSE … even a little closer than a humbucker on the bridge!  But here’s why:  That old design used a pair of magnets forced head-to head with a poor old pole screw/slug smashed in between to “charge” the pole-piece. The measured magnetism (gauss) at the actual pole screws in these is only about 200-300gauss, compare that to the 1000+ gauss of a typical Strat or Tele style pickup … there’s a HUGE difference here, buddy!  As you raise the pickup closer to the strings the tone gets brighter and more focused … now with a super bright single coil, that’s usually a bad thing, especially on the bridge pickup.  However, with the relatively warm tone, wide detection area, and inherently low magnetic pull of these archaic designs, that’s EXACTLY what makes them come alive

A P-90 sittin’ far away from the strings produces a downright fluffy/thuddy tone (with a lot of 60-cycle buzz, too) … hey, if that’s what you’re going for then do it!  Personally, if I want that tone, I just roll down the tone pot and maybe the volume a little. The truth is that you might find the tone you are looking for anywhere from the closest you can get those puppies to the strings all the way to as far as you can get them away from the strings (about 6-7mm is as far as you can go on a Les Paul style guitar).  As always, just remember this:

The closer you get to the strings the brighter, louder, and more focused the tone will get.

The further you move the pickup away from the strings the warmer, quieter, and less focused the tone will get.

And here is my last comment on this subject;  I have a 1958 Gibson ES125TD with a pair of original “dog-ear” P90s that are sitting WAAAAY further away from the strings than the recommendations I just gave above, and I wouldn’t even consider shimming them up closer.  Why? Because that warm, sloppy, sweet, fat tone is exactly what I’m looking for out of that guitar … so there, I just discounted everything I’ve said.  Go figure!

There ya have it, see y’all next time.

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