kasploosh.com

Two Humbuckers And Three Switches

This page describes the idea, used in Megalottacombo, of using three 6-position switches to wire up two humbucker pickups. One switch on each pickup allows selecting the coils of that pickup in interesting ways. Then a third switch between the two pickups allows selecting the two pickups in the same way. And the result is many possible combinations.

One Pickup

One pickup

On the previous page, I described how a 4-pole 6-position switch could be used to create six essential circuits for connecting the two two coils of a humbucker pickup.

You have four wires coming from the humbucker, two for each coil. The switch connects those four wires in different ways and gives you two wires of output.

If you have a one-humbucker guitar, you could almost be done at this point. Just add volume, tone and output jack.

Two Pickups

Two pickups

But this project is for a two-humbucker guitar, so let’s add our second pickup to the diagram.

If our 6-position switch worked for the first humbucker, obviously it will do the same job for the second humbucker.

At this point we have two humbuckers, and each one has its own switch. You could be done at this point, by connecting the output from the switches in series, or parallel, or with a selector switch.

Third 6-Position Switch

Third switch

What I did was take the same 6-position switch and use it to select between the two pickups, bridge and neck. This third switch follows the same logic, and provides the same essential circuits, but now between the two pickups.

This third switch allows you to select bridge only, neck only, bridge and neck in series, bridge and neck in parallel, in series but out of phase, and in parallel but out of phase.

The trio of 6-position switches are what leads to the many possible combinations of sounds. There are 216 possibilities (63 = 216), but not all of them are unique.

One of the neat things about having all three switches follow the same logic is that once you have memorized the logic for one switch, you have memorized it for all three.

One of the inconvenient things about this scheme is that most guitars do not have space for three switches like this, in addition to the other controls like volume and tone. My project is custom and doesn’t have this problem.

Schematic Diagram

Here is the schematic diagram of how I connected two humbucker pickups using three 4-pole 6-position switches. Notice that each of the switches is virtually identical in how it is wired.

The diagram is a little confusing with all the overlapping wires. The interactive demo farther down traces all of the paths in color, and demonstrates all the possibilities.

This diagram is also available as a PDF where it is a little sharper and clearer. Click the image for the PDF.

2013-Michael_Rickard-Megalottacombo-2-two_pickups-three_4P6T_switches.png

Switch section schematic diagram
Click for PDF

Interactive Demo

I have prepared the following cool (I think) interactive demo of the switches at work. Launch the demo, then use the controls to select different switch positions. The diagram will update as you make different selections, as if you were turning the knobs on the guitar.

Launch the interactive demo

SW1 - Bridge pickup coil selector
SW2 - Neck pickup coil selector
SW3 - Pickup selector
13975.98811