An All-Humbucking 5-Way Superswitch Circuit in an Electronic Guitar with 3 Single-Coil Pickups

© 2016 Don Baker

Legal Notice – Copyright and patent protections cover the material you are about to see and read.  Here’s how to avoid getting sued:

1. Build it with your own hands for your own personal use, at your own risk
2. Do not sell it or make it for sale
3. Do not take any money to do it for someone else
4. Do not reproduce it for any and all public distribution
5. Provide only links to this site with personal descriptions of how it worked for you
6. Do not try to profit from it in any manner, shape or form

Of course, some turkey may pop off and say, “This should all be free!”  See the post on “Electronic Freedom for who?”  Jeez, guy, you’re getting a free tutorial on how to make your guitar sound hum-free and awesome.  Isn’t that enough?

BTW – pay attention to the theory and triple-check everything, even what I write.

Preparing the guitar

A 5-way superswitch has two wafers with 2 pole terminals and 5 throw terminals each.  It is at least twice as wide as a regular 5-way guitar switch.  This may require you to cut or rout out some wood below it in your guitar’s electronics space under the pickguard.  You might want to paint any raw wood with shellac to avoid any problems with moisture uptake.

Humbucking works for low-frequency electromagnetic AC fields from things like transformers and motors, but the high frequency arc noise from fluorescent lights is something else.  If you can, get some brass shim stock from a machinist’s supply shop, of no more than 0.001 inch thickness.  It cuts with scissors and a razor knife, and folds and solders easily.  It will shield the electronics from electrostatic pickup, as from fluorescent lights.  Use it the cover the underside of the pickguard, and the inside of the of the guitar pickup and electronics space.

Here are two pictures showing a modified Fender Strat ™.

Shim stock applied to bottom of pickguard, where the original aluminum foil doesn’t cover

Shim stock applied to floor and walls of a Strat ™ pickup and electronics cavity, soldered together and grounded to guitar ground.

Note large tabs to right of pickup cavities for connection to the pickguard shield.  Note also the blue masking tape added to make sure that any changed wiring does not short out on the brass shim stock.

Before investing any time in this project, you have to check one very important thing.  Is the magnetic pole of the middle pickup (closest to the strings) opposite from the poles of the other two.  North or south does not matter, only that they are different.  You can check it with a magnetic compass, or see if the top of one pickup sticks magnetically to the tops of the other two.  Be very careful with small magnets, as the rare earth kind might be strong enough to damage the magnet in your pickup.  If you have one different from the other two in another position, neck or bridge, move it to the middle.

If you don’t have one different, the switch wiring to get all humbucking outputs will be very different.  If so, you might be able to figure it out by studying the patent and tutorials here, but that won’t be covered here and now.

Also, before starting to change any components, take pictures of everything, so you can put it back the way it was if something doesn’t work out.  If you don’t already know how to solder without damaging stuff, learn.

Theory

You can find a full description of how humbucking pickup pairs work together in these articles:

1. Wiring All-Humbucking Single-Coil Pickups
2. Notes on Humbucking Pair Placement
3. General Principles of Humbucking Pairs

Practice

I actually did this with one of my guitars, it worked out pretty good.  Here is a drawing showing the circuit diagram for wiring the neck, middle and bridge pickups to a 5-way superswitch to get 5 humbucking pairs: (N+M) the neck p/u in series with the middle p/u; (M+B) the middle in series with the bridge pickup; (N||M) the neck in parallel with the middle pickup; (M||B) the middle pickup in parallel with the bridge; and ((-N)||B) the neck in parallel with the bridge pickup (out of phase, or contra-phase, the other four are in-phase).  The connections tend to go from warmer to brighter from left to right in the diagram.

Note that wires are connected together only were joined by little extra dots.  The bar magnets in the diagram show the usual arrangement of magnetic pole polarity in most 3-pickup guitars.  All that matters is that the middle pickup has to opposite pole up compared to the other two.  The plus signs on each pickup indicate signals of the same phase for the same motion of a string.

Typically, if the pickups use shielded single-conductor wire, that is the center conductor.  If they use twisted pair wires, you will have to record which ones were connected to the ground before you removed any original circuit components.  The others are the “plus” side.

Take a good look at this drawing and make sure you understand “serial” and “parallel” connections before continuing.  Trace everything out until it is clear in your head.  For all you know, I might have made a mistake.  If it gets confusing, you may even have to pull the pickup wires out from under the pickguard and connect them together on a plastic breadboard block (outside the guitar) to test the circuit.

This is still not enough.  You need to write out or have a soldering diagram for the switch.  It has after all four pole terminals and 4×5 = 20 throw terminals for a total of 24.  Here is a diagram I used:

Note that wires are connected together only where joined by little extra dots.  Connections to all six wires of the pickups are show as N+, N- for the neck, M+, M- for the middle, and B+, B- for the bridge.  The pole terminals are shown as black arrows to indicate the wipers.  As the lever of the switch moves from the neck direction to the bridge direction, the wipers move from right to left over the throw terminals as indicated.  The outputs tend to go from warmer to brighter as the switch lever moves from towards the neck to towards the bridge, but you should verify that independently.  The output is the circle within a circle on the right.  The ground is the triangular set of horizontal lines on the lower right.

If you don’t know circuit symbols, take some time to learn.  The switches in both of these diagrams are set up like slide switches, because it’s easier to visualize.

Here is a picture of the wired 5-way superswitch showing the outside wafer, wipers and throw terminals, and the pole terminals, two on each side, with notes as to which end of which pickup connects to them.  A volume pot shows on the lower right.

Here is a picture of the other side with all the terminals for the N+ and N- wiper connections.

Here is a picture of the other side, with the terminals for the M+ and B- connections.

If you are handy with a soldering iron, this should be enough to get you going.  Remember, go slow and triple-check everything.  Not even I can keep things straight without a program.

A Final Note

There’s a good reason for handing this out for free personal use, but not for profit.  As yet, the established guitar companies don’t seem to know that they’ve missed any tricks.  But when they find out that you really can get 6 humbucking outputs (with a 4P6T switch) from three coils, 12 from four and 20 from five, they are going to have to do something about it.  If not for this, they could poach the patent and pretend that it was their idea.  But if enough people have tried this out from this site, then the guitar companies will become known for poaching patents from the elderly and disabled.

Not exactly good press.

Addendum 2016-06-30:

Actually the odd coil out can be put in any position, not just the middle.  But then you will have to rework the wiring and soldering diagrams.  Consider putting it at the neck.  Then the (N+B) pair is in phase and should have an even warmer tone than the (N+M) pair presented here.  And the (M||B) or even the (M+B) pair will have an even brighter tone than the (N||B) pair presented here.  But I recommend the (M+B) pair if the odd coil is at the neck, because the (M||B) pair will probably be very weak.

If you put the odd coil out at the bridge position, then the contra-phase N and M pairs for that position will be warmer than the contra-phase N and B pairs for the odd coil at the middle position, being farther from the bridge, or maybe brighter, being closer together.  The rules stated in General Principles of Humbucking Pairs may very well tend to cancel each other out, producing smaller differences in tone.  Because their midpoints are in the same position, the M and B in-phase pairs will be the same tone for either the odd coil in the middle or bridge position.  So any setup has to be tested and verified.

I presented the odd coil in the middle here merely because that is the way I first wired it up, leaving the coils where Fender put them.  Sometimes coils are made in different widths for different positions, the better to match the strings.  You may find, BTW, that the standard Strat coils are not matched, and will not produce perfect humbucking.  Mine weren’t.  The reasoning may be that the bridge coil needs some extra output to keep up in volume with the others.  Or it may be looking for a particular tone.

I think you might get an even wider range of tones by putting the odd coil at the neck.

I also took some $6 generic coils with ceramic magnets and attempted to change the polarity with a very strong rare earth magnet.  The polarity did change, but maybe not as strong as the original way.  It needs some work.