Advice on this HH coil split wiring?

[jagi]

Hi folks,

I'm very new to both playing electric guitars in general and guitar modding (and new to this forum), but I've started a project to refinish and rewire a cheapo guitar I bought on sale, mostly so I can learn and experiment. It's a HH guitar that I'm putting some new pickups in, and upgrading the crappy 3-way switch to a superswitch. I wanted to play around with coil splitting given the flexibility of the superswitch, and I thought it'd be cool to rotate the neck pickup so I can get hum-cancelling inner and outer coil split configurations. I came up with the following desired configuration for switch positions:

1. Bridge humbucker series
2. Inner coils parallel
3. Outer coils series parallel
4. Neck humbucker parallel
5. Neck humbucker series

I never found a good use for the middle position of neck + bridge, so I thought to try out the neck humbucker in parallel instead. I would appreciate input on if this configuration makes sense from a playing perspective. I'm not 100% set on the ordering, I might put the parallel neck as the center position.

I cobbled together a wiring diagram, combining two wiring diagrams I found from guitarelectronics.com (one diagram showed parallel pickup wiring, and the other showed inner/outer coil wiring) into this:



Ignore the coloring, it's kinda arbitrary. I am aware of the fact that I'll need to find out the color codes for the DiMarzio pickups I've ordered. Does this wiring look correct? My understanding is that I have full control over which coils are off or on for each switch position, with this setup of having the coil ends wired to each switch pole common. I can turn off either of the South coils by switching S. End to ground so that both start and end are grounded, and I can turn off the North coils by switching N. End to the hot line, so that both start and end are wired to hot and basically create a short circuit, bypassing the coil. And I can control a humbucker being series or parallel by either switching N. End and S. End together, or switching N. End to ground, and S. End to the output line. Is this the right way of understanding what's going on here?

Thanks in advance. I've had a lot of fun with this project so far and wanted to make sure I won't mess anything up too much before I break out the soldering iron.

[newey]

Your diagram looks OK except that, in the text of your post, you said you wanted position 3 to be the outer coils in series. You have the outer coils at 3, but they're in parallel, not series. This can be fairly easily fixed if you do want the outer coils in series. Disconnect the green jumper wire that goes between the 2 lower poles of the switch at position 3. The blue (S End) wire from the bridge HB needs to be wired to lug 3 on the upper right pole, so it connects to the N End (purple wire). The wire currently grounding the N purple wire at 3 is then removed. Thus, Bridge S Start will remain permanently grounded, Bridge S End coonect to Neck N end, neck S is permanently connected to output.

(BTW, the "End" of a coil wire is typically called the "Finish", not the "End". Doesn't really matter except if you abbreviate the wires as "NS, NF, SF, SS" everyone will understand what you mean without typing out "End".)

While your diagram will work as drawn, it could be simplified. Because you have both HB's "N Start" coils permanently wired to the output, this forces you into a lot of shorting of coils to themselves, rather than simply disconnecting the coil. And more solder joints means more potential points of failure. Since you are just learning, try redrawing the diagram, but connect the bridge "hot" to one pole of the switch and use that pole to switch the bridge "hot" in/out of the circuit. The bridge HB's middle wires would then both be controlled by one pole. See if you can work out the same wiring that way. The Neck wiring, since you want series/parallel coils for the neck, will stay largely the same (except where it connects to the bridge HB).

[jagi]

Actually I made a typo in the thread, I want both inner and outer coil configurations to be parallel as it is in the diagram.

Nice tip on simplifying the wiring. It makes sense that I didn't need to have dedicated poles for both bridge NF and SF, since I'm not using that humbucker in parallel at all. I think I've managed to follow what you suggested:





5 less lugs to solder.

I know that I can optimize the physical wiring a bit more, having all the connections to "hot" and "ground" on the switch be jumpers with one wire connecting to the output, like I did for NS in the new diagram. But my understanding is cleared up now, and I'm more confident that I can tweak this and experiment with different configurations if I want.

Thanks for all the tips and clarification on wiring terms, Newey. Much appreciated!

[stevewf]

Hi jagi. The diagram looks like it'll work. I noticed that the neck outer coil's start is "hanging on the hot" in positions 2&3 [edit: position 3 is HoH, 2 is shunted]. There's been some discussion about that in this forum; I don't understand the deeply technical stuff, but my understanding is that while HoH is not a problem itself, it does increase the possibility of hum in the system. [edit: likewise, shunting on the hot can be trouble]

So I tried to come up with a way that avoids HoH. It's in the "Spoiler" section below.

Now that there's evidence that it can be done without HoH, if you'd rather have another go at it yourself, then don't click "Spoiler"; otherwise my drawing will be revealed.

SPOILER: Click to show

I saw a mistake in my labelling of NS and NF, corrected here, important for hum-cancelling and phase:


(Old version here)
I tried to maintain the wire colors, but I was too rushed to keep the same layout as you made. Hope it's useable.

Make sure that another person checks my work before adopting it; I've posted more than my share of errors here!
Cheers

[jagi]

Interesting concept stevewf, I was wondering if there's any possibility of the "hanging" coils introducing noise or changing the tone, my thinking was there still could be an induced current in the coil if the circuit is closed. But I'm no electronics expert.

I looked at your diagram and I think I'm going to use that as the basis for what I do, it's a clean approach. Thanks for spending the time to make it.

I think I found a mistake on position 4, the neck south coil isn't wired to anything, but that's an easy fix with one more jumper. The rest all looked good to me.

I noticed that you wire it so that NS is grounded or connected to SF, and NF is connected to hot, which is reverse from what I've seen in lots of diagrams - NS is hot and NF is either tied to SF or grounded. Does it make any difference which direction the signal runs through the slug coil? (edit - just noticed the edit in your diagram! But I'm still curious, would the direction make a difference? Would this result in the coil being in a different phase?)

[reTrEaD]

Feb 19, 2024 1:12:52 GMT -5 jagi said:

Interesting concept stevewf , I was wondering if there's any possibility of the "hanging" coils introducing noise or changing the tone, my thinking was there still could be an induced current in the coil if the circuit is closed. But I'm no electronics expert.

A coil hanging from hot can allow hum to enter into the system (although it won't affect the tone if the coil isn't shunted. The unused coil can act like an antenna.

A shunted coil can affect the tone of the adjacent coil in a HB. The eddy current in the shunted coil can cause a slight loss of treble in the other coil.

We prefer to avoid these small issues but it shouldn't be a deal-breaker if there's no other way around them.

Feb 19, 2024 1:12:52 GMT -5 jagi said:

I noticed that you wire it so that NS is grounded or connected to SF, and NF is connected to hot, which is reverse from what I've seen in lots of diagrams - NS is hot and NF is either tied to SF or grounded. Does it make any difference which direction the signal runs through the slug coil? (edit - just noticed the edit in your diagram! But I'm still curious, would the direction make a difference? Would this result in the coil being in a different phase?)

Yes, exchanging the two ends of a coil will result in that coil being out of phase. Meaningless if only one coil is being used. Hugely important if there is more than one coil in the circuit.

---

When I read what you're trying to accomplish, my first thought was on the basic architecture.
I figured the SS of each HB going to ground,
the NF of the Neck pickup going to one common of the superswitch,
the NF of the Bridge pickup going to another common of the superswitch,
and the other two commons of the superswitch tied together going to the output,
would allow plenty of possible hum-canceling combinations.

Neck HB series
Neck HB parallel
Inner coils series
Inner coils parallel
Outer coils series
Outer coils parallel
Bridge HB series
Bridge HB parallel
and even ...
Both series HBs combined in parallel with each other.

I butchered your drawing and connected the dots with the architecture I described to get the 5 selections you specified.

SPOILER: Click to show