How to open a humbucker and reverse the polarity

Issue 69 September 04, 2008

Ever try to open a humbucker?

How do you pop open a humbucker?

This Trade Secret is about switching a humbucker’s polarity, but the hard part is getting the doggone pickup open!

A customer called the other day with a simple wiring question.

He had two 4-lead humbuckers to use with our PRS wiring kit. The kit instructions call for one of the pickups to have opposing magnetic polarity. That's easily achieved by pulling and flipping the magnet this way:

  1. Loosen the polepiece screws so they clear the baseplate, then loosen the bobbin screws a bit so the magnet slides out.
  2. Photo: removing the humbucker's magnet
  3. Be careful so you don’t damage any of the delicate connection wires.
  4. Photo: removing the humbucker's magnet
  5. Roll the magnet over, flipping it 180 degrees. This is the move that switches the polarity.
  6. Photo: removing the humbucker's magnet

Re-install the rotated magnet, sliding it back where it came from. Simple enough, right?

That’s how I described the job to the customer. But then he asked, “But how do I get the darn cover off?” Let me show you how I do it...

Photo: replacing the humbucker's magnet

Removing the cover from a humbucker can be tricky.

Generally, the cover is soldered on. Removing it is even a little risky, because it’s easy to damage the coil (don’t ask how I know!!!). To do this you’ll need two clamps, a razor blade and a soldering iron.

I like to hold the pickup in a cam clamp while I’m working on it. The cork lining in the jaws doesn’t mar the plating.

Photo: clamping the humbucker

While your soldering iron heats up, insert the corner of a single-edge razor blade between the cover and the baseplate of the pickup.

It only takes a touch of the hot iron to melt the solder. As soon as it does, carefully work the blade between the cover and baseplate just enough to keep the solder joint apart while the solder hardens.

Photo: desoldering the humbucker cover

When the solder cools, the blade slides right out. Do this on both sides, of course.

The cover is now loose and ready to come off.

Photo: removing the humbucker cover

After flipping the magnet, it’s time to put the cover back on. But is that really what you want to do?

Here’s a decision to think about:

For those of us who like the sweet sound of a covered pickup, here’s a quick way to put it back on.

I use a mini cam clamp to make sure the cover fits to the pickup as tightly as possible.

Photo: clamping the humbucker cover

I’ll then use my medium clamp to bring the sides in tight against the baseplate.

Photo: clamping the humbucker cover

When the sides are clamped, remove the mini cam. A quick touch of a hot soldering iron will flow the existing solder together and secure the cover back in place.

Photo: resoldering the humbucker cover

When the solder has cooled, remove the clamp and your reversed-polarity pickup is ready to wire up in PRS fashion!

Photo: reversed-polarity humbucker

Cover your pickups or let them run around naked?

Since the cover itself creates some capacitance, it can take the edge off the sound of the pickup. Some players prefer the brighter sound of an uncovered pickup, so they leave the covers off. That’s why we offer our Golden Age Humbuckers in no-cover versions like the "Zebra" at right.

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