This is where we discuss the juicy stuff. Before you read on, please make sure you understand everything mentioned in Part I: The Basics. I will take those things for granted.

If you haven’t read Part I: The Basics , now would be the time to.

Same disclaimer, warnings and convention apply as in Part I.

I may create some complete setup examples where I deem necessary, but I can’t possibly cover all the combinations. So I will be explaining things in minimal setups or subsections of schematics. Again, think modularity. The fact that I don’t draw other elements of a wiring setup is because they are irrelevant.

Contents:

• Additional switches
• Humbucker modes
• Serial/parallel mod
• Serial/single mod.
• Phase switch
• Blow switch
• Killswitch
• Override swich
• Position reallocation
  
• My personal favourite humbucker mode mod

Additional switches

In order to mod a guitar’s wiring to get it to do more tricks, you will usually need some extra switches. The most common switch for mods is the double-pole double-throw (DPDT) on-on switch. It’s a switch with two pairs of inputs and an output for each pair. It has only two positions, meaning that either input A or input B will have to be active but they can’t both be active a the same time. This switch is commonly used because it can be integrated in push/pull pot(entiometer)s used for volume or tone, which allows you to add a switch without drilling a new hole for it. I will be using it for nearly all of the mods discussed here.

Humbucker modes

A 4-conductor humbucker (that means it has 4 wires coming out of it, plus shield wire if any) is basically like two single coil pickups in one package. The ways you can connect the coils of a humbucker can be extended to connecting any two or more pickups, so this section comes first in this article. It is also a lot more common to want to mod a setup that has humbuckers than a setup with only single coils.

There are 6 ways to use a humbucker on its own:

pic 12

Depending on the humbucker, not all of these modes may sound usable. It goes without saying that the different modes must be achieved through a switch of some sort. Except for the 2 out of phase modes, all the others are common in humbucker mods with serial being the most common and factory setting, followed by one of the single coil modes.

The same modes can be applied to entire pickups. The normal setup with a 3-way or 5-way switch has the pickups working either alone or in parallel with one of the other pickups. Connecting two individual pickups serially is a bit cumbersome and gets in the way of normal pickup selection.

In Part I of the article, we saw what some major hot points are (switch connections, volume controls) and ground points (back of a volume pot almost always). When, in ANY way that you can come up with, the connection requirements of pic 12 are met, the pickup enters that mode. It would be useful to make an example or two. I will be using the 2 humbucker setup, as it is more common for people to want to modify that (only two pickups, only 3 switch positions). For space and clarity I’m leaving the tone controls out of the picture. Consult pic 8 if you don’t remember how to connect tone controls.

Notice that a mode switch will replace any coil splitting from the 5-way switch.

Serial - Parallel

I will add a serial/parallel mode switch to the volume pot of one of the 2 pickups. Same concept can be applied for the other pickup as well. A second dpdt switch will be necessary if you decide to do that.

pic 13a

I want you to focus on the blue and the black wires. The rest is exactly the same as pic 8. In position 1 of the switch, blue and black are connected to each other with the purple jumper connection. This is the serial connection. In position 2, the blue is connected to a hot point (the volume input) and the black to a ground (any will do).  That’s the parallel connection. Don’t let the presence of other stuff in the context confuse you. Track down the wires to the nearest hot or ground and match the setup to the modes in pic 12.

Here it is also for a single-single-humbucker setup, just to show you that nothing changes for the switch regardless of the context it is in. Same applies to the other mode mods that follow. Again, I omitted the tone control.

  pic 13b

Ok, maybe one thing changes, and it is important to mention it. Notice the orange wire? Can you see what it does? In parallel mode, the two coils become independent pickups. One of them is already connected to switch, but the other one isn’t. If you connect the second coil directly to hot on the volume control, it will always be on, never off. Unless you have thought about it and it’s what you want (having the bridge coil always on will give you some neck-bridge and neck-middle-bridge sounds), you will want to be able to control when the second coil in on. Most commonly you will want it to be on at the same time as the other coil. If you’re feeling crazy, you may want to tie that coil to one of the other pickups instead of it’s sibling coil.

Serial - Single coil

From parallel to single coil it is very simple. From position 2 of the dpdt switch in pic 13 remove either the “green” (to keep only coil B) or the “red” wire (to keep only coil A).  The two will sound different because the coils are offset. Try both and choose which you like most. I hope I don’t have to draw that for you but here goes anyway.

pic 14

Phase Switch

Connecting the coils of a humbucker in out of phase ways is not common. Instead I’ll show you how to reverse the phase of the entire pickup. The result of phase reversion is only apparent when the pickup is blended with a pickup whose phase has not been reversed, namely only in the middle position of the 3-way of the example.

pic 15

With this mod I introduce to you the very useful “X jumper” connection as I call it, because of its shape. It is the connection that reverses the roles of two wires. First of all notice that the humbucker is in serial mode always.  Splitting or setting it in parallel mode complicates the use of a phase switch because you then have more wires to deal with. Also notice I’ve detached BOTH the red and green wire of the humbucker from the volume. I need both of them to reverse the phase. If you look at pic 12, phase reversion occurs when you use the normal ground wire of a pickup as a hot wire and the normal hot wire as a ground wire. If coil-split wires are in use, they too must be reversed. Now lets look at the “X”. Follow the wires. In position 1 of the switch the red wire from the pickup crosses over the switch and lands on the hot input of the volume. Similarly the green wire crosses over and lands on the back of the volume (ground). In position 2 of the switch, the red wire lands on the ground at the back of the volume while the green wire lands on the hot input of the volume.

“Blow” switch

This switch will activate all your pickups at once, regardless of what position the 5-way is at. Obviously it is a mod that only makes sense if you have 3 pickups. If you have 2 you can have them all on as part of the normal pickup selection. Can you think of a way to turn all pickups on with a dpdt switch? Remember, the dpdt only has two interfaces and you have 3 pickups. So straightforward turning each  pickup on is out of the question. Bypass the 5-way? How in a switchable way? Too complex.

What if all the inputs of the 5-way received the same signal? What if we blended the signal of the 3 pickups before it even reached the switch? 3 inputs need 2 jumper connections so that they are all connected with one another. If they are all connected with one another they all receive the same signal, the blended signal of the 3 pickups. 2 switchable jumpers, 2 interfaces on the dpdt switch… Got the idea yet?

pic 16

In position 1 of the dpdt, nothing happens. In position 2 the middle and bridge pickups’ wires are joined. But the middle pickup wire crosses over to the other side of the switch too. There it is joined with the nick pickup’s wire. If A connects to B and A connects to C then B is also connected to C. So there, by pulling up the knob you blend the 3 pickups before the signal reaches the 5-way switch.

Notice that the blow switch is a parallel control. Which means the rest of the wirinig is identical to pic 8 in Part I of the article. I’ve added a coil split for the humbucker. It’s not necessary, I just wanted to remind you that there may be more elements in the circuit than the minimal that I’m using for my examples.

“Kill” Switch

That’s another mod that’s catching on. The kill switch is a very simple device. It is a button that when pressed it interrupts the circuit. Like the button that turns on the light in your fridge when you open the fridge door. On a guitar you’ll probably want that to be the final global control so that it kills the signal no matter what pickup configuration you’re using. So it will be the last thing before the output jack. It is serially connected on the hot wire.

pic 17

 Middle override switch

This concerns guitars with the H-S-H pickup configuration. The goal of this mod is to kick the single coil out of the way and make the guitar act like an H-H configuration. To achieve this we use a modified blow switch. Neck and bridge are solidly connected to the 5-way. A branch connects them to a DPDT as well. The middle pickup goes directly to the DPDT. Normally, the DPDT output sends the single coil signal back to the switch. When activated, the single coil is cut and the neck and bridge are channelled to the middle of the switch instead, in blow-fashion. This way you get neck in position 1, bridge in pos5 and neck-bridge in all the positions in between.

It is a cool mod for when you need simpler operation or for noisy environments where the single coil hums too much to be usable.

  pic 18

 Everything not shown in the scematic is to remain as is.

Position re-allocation for strats

Single coils hum. Strats typically have 3 of them but positions 2 and 4 of the 5-way are humcancelling thanks to using two pickups each, so many players  use them almost exclusivelly. Positions 2 and 4 however are hard to target on the fly. So if they are your main playing positions, this is a mod the will cost less than putting a set of silent pickups. It solves the accessibility issue of positions 2 and 4, not the hum issue itself.

  pic 19

The mod requires an extended 5-way switch. The idea is to rearrange the positions on the switch so to get the hum-cancelling ones to be in positions 1 and 5 which are easy to target. This will produce:

1 neck - middle

2 neck

3 middle

4 bridge

5 bridge- middle

Grand Mode-Switch

My favourite switch for humbucker mode switching is the 4-pole 5-way. It has 4 interfaces with 5 independent positions each. It is ideal for toying with the modes of your humbuckers. However, since it is a 5 way, it poses a problem. If you replace with it your regular 5-way, then you have to find a different way to blend the pickups. Otherwise you will have to cut a new slot for it. In that case, it’s best to use a guitar with a pickguard. If you regret cutting the slot, you can buy a new pickguard and it’s all good again.

In the past I used to show my own guitar’s crazy mod at this point. Instead I’ll show something a little simpler. Two humbuckers, one 4-pole 5-way, one 3-way (it will go in the spot of a tone control) and a push-pull volume. The tone spot will be replaced by the 3-way, so we’ll have no tone control (I rarely use it anyway). This version of my mod is meant so you can install it on many metal guitars without cutting new holes and stuff.

  pic 20

Panic yet? Don’t! Everything we have learned so far applies with no deviation. Don’t let the 5-way scare you. The philosophy is exactly the same as for the examples 13-16, but instead of working with 2 positions, we have 5 at our disposal. The phase switch also does not deviate from pic 15. The top pickup is connected to the 3 way and the mode switch as in all the previous examples. The bottom pickup combines the mode switch with a phase switch. The orange wires do exactly what they do in pic 13b, which is to ensure you have no renegade coils permanently switched on. The blue wires assist the orange ones in completing that task. Each orange wire goes exactly where the red wire of the other coil of the same pickup goes. Each blue wire goes exactly where the green wire of the other coil goes. This ensures that no matter which mode you are using, the phase and 3-way switches will react in a consistent way.

I urge you to try to figure out yourself what mode each position of the 5-way represents. Consider it a test to see if you understood everything I’ve tried to explain. Just track down the wires of each coil and see where they end up for different switch positions.

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don’t cheat

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…

The switch treats the two humbuckers in exactly the same way, meaning they will be in the same mode always. You can set it up to engage a different mode for each pickup if you wish to. Just consult pic 12 for the necessary connections. Here, in position 1, the purple jumper wire connects the coils serially. Position 2 is the parallel mode. Position 3 is the grey coil alone and position 4 is the white coil alone. Position 5… is mute. No coil is active. Try to see if you can use position 5 to get the bridge humbucker to be serial and the neck one to be parallel, based on the knowledge you should have acquired by now.

There’s not much to say about the phase switch. For the same reason the orange wires need to be attached to the blend switch, the orange and blue wire must also be attached to the phase switch. You want to reverse the phase of whichever portion of the humbucker is active and this is the only way to do it.

Hopefully I've given you all the tools you need to solve wiring problems and design your own wiring mods. Now the best way for all of this to stay with you is... trial and error. Take a cheap guitar and start trying out stuff and see what the result of different mistakes is.