Reverse magnet humbucker convention

kdas3

New member
Messages
24
Hi everyone,

First some preliminaries:

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[*]A standard single coil has a magnetic polarity which is south up. A standard RW/RP single coil has a magnetic polarity which is north up. Edit: Actually, I believe these days that Fender usually (but not always!) have their standard single coils as north up, and their RW/RP as south up, so there is no convention regarding polarity with single coils!
[*] A standard humbucker has a slug coil with a north magnetic polarity, and a screw coil with a south magnetic polarity.
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A bit of an aside: I have an issue with the convention that manufacturers use to label their 4 conductor wires for humbuckers. As we know, the slug and screw coils each have a start and finish wire. Since the slug coil usually corresponds to the north coil, and the screw coil usually corresponds to the south coil, manufacturers will call the wires north start, north finish, south start, south finish (let's call this the manufacturer convention). Personally I think it should be slug start, slug finish, screw start, screw finish (let's call this my convention). My reasons:

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[*]For a person new to the world of guitar wiring, if we use my convention, it is pretty clear that the screw start and finish are the wires coming out of the screw coil. Maybe slug is a bit harder to figure out (why is it called slug?). Nonetheless, this is not obvious if you use the manufacturer convention.
[*]If you flip the magnet of the humbucker, which is extremely common these days in many modern superstrat style guitars, then the manufacturer convention no longer makes sense, as the slug coil will become the south coil, yet according to the manufacturer convention, the wires coming out of it will be named north start and north finish. Huh?
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So, this annoys me. Anyway, that was a mini rant before my actual question. In HH superstrat style guitars, there is often an inner or outer coils setting on the 5 way switch. They are humcancelling, and this is achieved by reversing one of the humbucker's magnets. I believe manufacturers usually choose to reverse the neck humbucker's magnet (e.g., Ibanez). My question is, why the neck instead of the bridge? Either choice will essentially work exactly the same.

My thoughts on why this is the case:

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[*]Players are more likely to replace the bridge humbucker, so using a conventional one there will make replacing less of a hassle.
[*] I think (not entirely sure!) standard HSS guitars come with a conventional bridge hum (north slug), and unconventional single coils. Why? Suppose on the contrary you used conventional single coils and humbucker. Then, reading from neck to bridge, you get South North North South (here on S N NS). So, the autosplit in position 2 won't be humcancelling. To fix it, either flip the bridge hum magnet, or exchange the neck and mid single coils so that the neck is a RW/RP (north up). Manufacturers seem to prefer to exchange the single coils, and I believe this is quite easy for them, as often the neck and mid are identically speced other than the RW/RP bit. The advantage again I believe is that this makes it easier for players to replace the bridge hum, and potentially swap it out with a bridge hum taken from a superstrat style HH guitar, which we just established usually has a conventional bridge hum.
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A case against flipping the neck hum magnet:

Recently (like 3 years ago) I converted an SSS guitar to HSS. You may have seen a big post I did about modifying the Suhr HSS wiring schematic on the forum. I had conventional Lollar vintage blondes in my guitar, meaning I had the setup S N S. If I were to replace the bridge single with a humbucker I would either need to flip the humbucker magnet, or exchange the roles of the middle and neck pickup in order to get humcancelling in pos 2. Now, for Lollar pickups at least, the neck and middle pickups are actually not identically wound, specifically the middle is slightly hotter. So it wasn't possible for me to exchange the neck and middle. Also, I think there could be issues with wire lengths if you were to do this. So I had to get my bridge hum with a flipped magnet, which was no issue because Bareknuckle do this if you ask them when you order this. My only gripe is...now I have HH guitars with flipped magnet neck hums, and a HSS with a flipped magnet bridge hum. So I can't exchange the bridge hums between them. Annoying...

Any other suggestions as to why the neck hum magnet is usually flipped in HH superstrat style guitars? Or cases where manufacturers actually flip the bridge hum magnet? Actually, I don't know what PRS do...
 

DuckBaloo

Senior member
Messages
281
There is no industry standard. South Up vs. North Up, or Slug North vs Slug South and wind wind direction all vary from manufacturer to manufacturer or even between different years of manufacture (especially with Fender). Plus not all humbuckers use screws and slugs.

Each pickup  needs to be treated as unique whenever mixing and matching. And to set more rules  than that is pretty futile.
 

kdas3

New member
Messages
24
Apologies. I have not seen a (modern) humbucker manufacturer who usually manufacturers a slug/screw style humbucker with a slug south coil. If you could let me know of one, that would be great! Your comment on blade/other style humbuckers is a valid one. As for single coils, I believe you are right. Actually I haven't researched this recently but I believe Fender now usually use North up for their usual singles, and South up for their RW/RP. Unless they're some sort of reissue set. And they've been pretty inconsistent over the years. So...ignore what I said about 'conventional single coils'.
 

kdas3

New member
Messages
24
Of course for humbuckers that don't use slug/screws then you obviously can't name the wires after slug/screw. So I guess the best thing we have to name the wires after are the polarities of the coils, whatever they may be. And if you flip the magnet then you just need to take that into account. Okay I am satisfied with that!
 

JohnnyHardtail

Senior member
Messages
319
Suhr SSV neck humbuckers have the magnet flipped by default, so you you end up with South magnetic polarity on the slug coil.  It is also reverse wound and the wire colours are swapped between the slug and Screw coils.  In this case the Slug pole has green and red wires, but I wouldn't know which is the start and finish unless I take the pickup apart to check.

 

kdas3

New member
Messages
24
JohnnyHardtail said:
Suhr SSV neck humbuckers have the magnet flipped by default, so you you end up with South magnetic polarity on the slug coil.  It is also reverse wound and the wire colours are swapped between the slug and Screw coils.  In this case the Slug pole has green and red wires, but I wouldn't know which is the start and finish unless I take the pickup apart to check.

Oh that is interesting to know! So by default if I buy a SSV neck humbucker from Suhr, the slug will be south? That works well for HH style superstrats, but what about HSH style superstrats? Supposing your middle pickup is south up, then I believe you will have humcancelling in pos 2 (bridge slug and mid) but not in pos 4 (neck slug and mid).

I can't remember if Bareknuckle swap the wire colours when ordered with a magnet flip. I'd like to think they do as it seems like the logical decision.
 

JohnnyHardtail

Senior member
Messages
319
kdas3 said:
Oh that is interesting to know! So by default if I buy a SSV neck humbucker from Suhr, the slug will be south? That works well for HH style superstrats, but what about HSH style superstrats? Supposing your middle pickup is south up, then I believe you will have humcancelling in pos 2 (bridge slug and mid) but not in pos 4 (neck slug and mid).

Actually its no problem for HSH wiring in position 4.  The neck humbucker can be wired with the red/white wires from the neck humbucker to be grounded in position 4 (same as the bridge pickup in pos 2).  You will get a the north coil of the humbucker in postion 4, so its hum cancelling with the middle pickup.  The difference with the Suhr neck humbucker is the north coil is the screw coil instead of slug coil.  People  using a conventional HSH wiring scheme will get the correct hum cancelling in the notch positions, and they may not even be aware the magnetic polarity of the neck humbucker has been swapped.

 

kdas3

New member
Messages
24
Yes in pos 4 you can split to the screw coil (which would be north for this SSV humbucker) and get humcancelling. This is not traditional for HSH guitars though, see for example

https://www.ibanez.com/usa/products/detail/rg8570z_00_03.html

The neck screw sounds different to the neck slug, meaning that neck slug + mid vs neck screw + mid will sound different. It's not as drastic as the difference between bridge slug vs bridge screw, but still audible.

In any case, I believe you can always get humcancelling by splitting to the correct coil (as long as the types of switches etc you have allows for it). You may have to manually 'reverse the wind' by reversing the roles of the starts and finishes, but it should be doable. For example, in a HH guitar where each humbucker has a north slug, you can get humcancelling by combining the neck slug and bridge screw, ensuring that one is reverse wound (meaning you may need to swap the wires around). It won't sound the same as both slugs together though.

Regarding terminology, since not all humbuckers use slugs and screws, maybe I should call the slug the inner coil and the screw the outer coil. Or maybe back and front coils (the neck back coil would be slug, the bridge back coil would be screw...). That's fairly consistent unless you rotate your humbucker...okay fine it will never catch on!
 

stratamania

Senior member
Messages
9,204
The terms inner coil and outer coil are quite commonly used so you would not be being too radical to use those terms.
 
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