Can You Explain This Wiring?

[thegummy]

Below is the wiring diagram for a guitar I have with a coil tap on a push-pull.

The green represents the North/South finish wires and the 3-way pickup selector switch is at the bottom.

Could anyone explain why it has been wired this way as opposed to the more standard way of coil tapping where the North/South finish wires both just get grounded?

 

[Chistopher]

Re: Can You Explain This Wiring?

There are two ways to coil split a humbucker. The way you see it traditionally done is by shunting the red/white connection to the ground. This makes it so that one of the coils (we'll call it coil A) has both its leads going to the ground, taking it out of the circuit. Coil A is silent, Coil B is not.

Another way to do it is to send the red/white connection to the output, this makes it so that both of the leads on coil B go to output, this also takes it out of the circuit. Coil B is silent, coil A is not.

Does this make sense? The only difference between the two methods is which coil is active during the split. There are a few other ways to do it as well, which I won't explain here (unless you want me to), but this way is generally the easiest and works completly fine in 98% of circumstances.

 

[thegummy]

Re: Can You Explain This Wiring?

There are two ways to coil split a humbucker. The way you see it traditionally done is by shunting the red/white connection to the ground. This makes it so that one of the coils (we'll call it coil A) has both its leads going to the ground, taking it out of the circuit. Coil A is silent, Coil B is not.

Another way to do it is to send the red/white connection to the output, this makes it so that both of the leads on coil B go to output, this also takes it out of the circuit. Coil B is silent, coil A is not.

Does this make sense? The only difference between the two methods is which coil is active during the split. There are a few other ways to do it as well, which I won't explain here (unless you want me to), but this way is generally the easiest and works completly fine in 98% of circumstances.

Thanks for the reply Christopher.

Any idea why the neck and bridge pickups have been coil split in different ways on this guitar?

Looking at the SD diagram, in that example they're both split by shunting the red/white to ground. Is it that in the SD wiring, it would be the slug coil that gets split on both but on this guitar, neck is screw while bridge is slug?

 

[thegummy]

Re: Can You Explain This Wiring?

Another couple of questions - if this wiring is indeed to select different coils on each pickup, why not just physically turn the whole humbucker round to achieve this?

Is this anything to do with making the coil-split middle position hum-cancelling?

 

[thegummy]

Re: Can You Explain This Wiring?

The more I think about it, the more I'm convinced that the coil-split middle position hum-cancelling is the exact reason it's wired this way.

If I'm wrong, hopefully someone will correct me

 

[beaubrummels]

Re: Can You Explain This Wiring?

Yeah to me it looks like its neck slug / bridge screw, effectively getting Artie's "slutbucker" (tm) I believe. (Can't remember if there was more to Artie's slutbucker than just getting a wide humbucker from the coils like that?)

 

[Teleplayer]

Re: Can You Explain This Wiring?

That is the same switch wiring I used on my HH guitar for coil splits. The coil split is hum cancelling in center position without the need to swap the magnet polarity.

For my guitar I split the bridge pickup so it activates the slug side coil, while the neck pickup activates the screw side coil. Your diagram appears to do the same thing (assuming neck pickup is at the top).

 

[Artie]

Re: Can You Explain This Wiring?

I'm assuming that those aren't SD pups, because that diagram wouldn't make any sense. Neither pup is ever in it's series mode, and only the bridge pup has both coils on, (in parallel), when the push-pull is down. None of which makes any sense. Can you identify what pups these are, or what guitar their in?

 

[thegummy]

Re: Can You Explain This Wiring?

I'm assuming that those aren't SD pups, because that diagram wouldn't make any sense. Neither pup is ever in it's series mode, and only the bridge pup has both coils on, (in parallel), when the push-pull is down. None of which makes any sense. Can you identify what pups these are, or what guitar their in?

The pickups are from a PRS SE Custom 24.

The black and red in the diagram would be equivalent to black and green on SD pickups but I'm not sure which is which (or even if they're the same on both) due to the way they're wired.

As mention in the post, the green on the diagram is the North/South finish which would be the red and white on SD pickups.

I'm quite confident this has been solved and it's done that way so that when both pickups are selected when coil-split they are hum-cancelling.

 

[thegummy]

Re: Can You Explain This Wiring?

I wired up the guitar as per the bog-standard SD 2-hum wiring, leaving out the coil split and having both black wires going to ground and both reds going to the selector switch.

This caused the middle position to sound very weird (in my opinion really bad) which I think may be that they were out of phase.

I swapped round the red & black on one of the pickups and the middle position is back to normal.

Does this mean that the pickups have a different colour scheme to each other where the black and red wires are reversed?