Dual Coil Split Push pull w/Splits at .047

[frets]

John or other Angels,

Is it possible; and if so, “How” to obtain a dual coil split (know how to do that) but so that when the coil splits are engaged (push pull pulled up) it kicks in a .047 cap. So, one push pull, two simultaneous coil splits, in split mode there would be .047 tone.

Thank you !😻

[Deleted]

Think it is possible.
I can picture a few possible outcomes.

I am worried that when this Hum/single is not selected the tone can be still active and therefore would may need to be linked with the pickup selection switch (lever etc)
That is of you have a master tone


If it has own tone that lot easier
Then you use one side of the 2P2T Push pull for the Bring the Middle to Ground/output depending on which one out of the two pickups you want
then can just Flip the 47nF or (im guessing) 22nF in for the Capacitory

I am guessing with a few things, that you would want a 250K with 47nF (Fender) when on a Single and 500K with 22nF (Gibson) for Hum
which you can do in the same pot with Wafer Moving..



I think your after the top one, just changes the Capacitor depending on single/hum
The bottom one is if you wanted 250K with 47nF and 500K with 22nF on the same POT (may mean making TWO of these and mixing the 250/500K wafers over)
Then again Push Pull comes with one wafer

[col]

@angellahash

Unless I am missing something, the shunted coil would be better placed at the ground end of the series. This way, the shunted coil can have no effect effect upon the circuit.

[Deleted]

When two ends are the same ..it has no effect.. how birds dont fry on power lines


What happens when you short circuit a system..just bypass that part..
The thing is the pickup is the power supply.. but if you have both ends the same there is no power.

Its the difference that is how you get it



Think two light bulbs in a row.😓
Live to light A and then light B then Ground/Natural. Both lights on
Now think we jump Live to in between Light A and Light B. What happens light B is on but light A is maybe so faint you cant see it on..
Shorted Light A

[ashcatlt]

The argument continues to rage about exactly what if any effect shorting one coil of an HB might have. I’m willing to accept the idea that it might “steal” some energy from the string, reducing sustain by some minuscule amount and possibly even affecting the harmonic series coming off the string itself. I do not believe that it has any real electronic effect, though. It can’t contribute enough to matter in terms of level, frequency response, or noise***. And I totally don’t believe it matters which coil you short for any of those things either. Yes, the coils aren’t identical so there will be some variation there, and they are sensing slightly different spots on the string so slightly different harmonics picked up, but it doesn’t matter whether it’s on top or bottom of the series stack.


All that said, none of the above actually addresses the question in the OP. They want to use one switch to split two humbuckers AND switch the cap, which I’m pretty sure can’t happen with a DPDT. Well, at least not passively.


***I suppose all of this is compared to just leaving that coil open and completely unconnected. I’m obviously not saying that one coil will not be different from other in series. That makes a big difference. But shorting is most definitely better than leaving one end of the coil unconnected and hanging in the cosmic wind. In that case, it probably will depend which side of the circuit it’s hanging from. Most guitars leave unused coils “hanging from ground”, and nobody complains, but we tend to try not to leave coils “hanging from hot” because the potential for extra noise is much worse than any questionable tonal effect of shorting the coil instead.

[frets]

Thanks Angel and Ash.  I agree wholeheartedly with you Ash but what is a “better coil split?”  Especially if one is using one pot to split two pups? I’m doing that all the time.  Even do the triple split.  But they all have the problems you mentioned. They never fully split and the coils produce a weaker signal.

Getting back to my questions of a coil split with an .047, I found this in my files.  I don’t know where it came from.  It very well could have come off of Guitarnutz; but, I do remember writing the notes on it.  

[col]

Aug 4, 2021 17:38:10 GMT -5 ashcatlt said:

The argument continues to rage about exactly what if any effect shorting one coil of an HB might have. I’m willing to accept the idea that it might “steal” some energy from the string, reducing sustain by some minuscule amount and possibly even affecting the harmonic series coming off the string itself. I do not believe that it has any real electronic effect, though. It can’t contribute enough to matter in terms of level, frequency response, or noise***. And I totally don’t believe it matters which coil you short for any of those things either. Yes, the coils aren’t identical so there will be some variation there, and they are sensing slightly different spots on the string so slightly different harmonics picked up, but it doesn’t matter whether it’s on top or bottom of the series stack.


All that said, none of the above actually addresses the question in the OP. They want to use one switch to split two humbuckers AND switch the cap, which I’m pretty sure can’t happen with a DPDT. Well, at least not passively.


***I suppose all of this is compared to just leaving that coil open and completely unconnected. I’m obviously not saying that one coil will not be different from other in series. That makes a big difference. But shorting is most definitely better than leaving one end of the coil unconnected and hanging in the cosmic wind. In that case, it probably will depend which side of the circuit it’s hanging from. Most guitars leave unused coils “hanging from ground”, and nobody complains, but we tend to try not to leave coils “hanging from hot” because the potential for extra noise is much worse than any questionable tonal effect of shorting the coil instead.

Apologies for continuing with the off-topic discussion here, but - assuming that shunted coils do indeed have an (appreciable) effect upon the sound - does placing the shunted coil at ground negate the effect? From the above and having read around a little more about this, it seems not. Do I understand this correctly?

[ashcatlt]

Aug 4, 2021 21:03:54 GMT -5 frets said:

They never fully split...

What? I certainly never said anything of the sort. Typical coil-shorted-split is about as fully split as you can get. Only one of the coils contributes meaningfully to the sound. The picture you posted doesn’t fully split, but just an RC filter parallel to one of the coils which gives us a version of what we around here usually call “broadbucker” tone. It’s something like HB bass but SC treble, though it can be tough to get those two balanced in a way that sounds natural, which I’d imagine is what the resistor here is trying to accomplish.

...and the coils produce a weaker signal.

I mean, the un-shorted coil generates the same signal it otherwise would, which is exactly half the voltage that you’d get from the full humbucker because, like, math. The individual coils of an HB tend to be slightly lighter wound than a typical SC, but honestly there’s a lot of variability in both. I’ve got a 16K rail humbucker in one of my guitars. When split, it’s 8K, which is about the full DC resistance of the PAF HBs in a couple of my other guitars. If I split one of those PAFs, it’s be 4K, which is still bigger than many single coils, so...

The question I was addressing is exactly what the shorted coil might be doing. There is a reasonable argument that says it’s still generating the same signal that it otherwise would, but since it’s shorted, none of that actually contributes to the output signal. Certain physical laws say that the energy generated (wasted) in that shorted coil has to come from somewhere, and that somewhere basically has to be the strings. I’ve seen some convincing evidence that this does have a measurable effect on the actual vibration of the string, but it was kind of just barely outside the margin of error and in actual experience, it’s never been an issue. Like there are many other things that will affect sustain and stuff much more.

@col” said:

Do I understand this correctly?

Yeah I think so. It doesn’t matter which coil you short. You might have a preference as to slug vs screw or inner vs outer, but having the shorted coil “closer to ground” doesn’t help enough to worry about. We usually choose for convenience based on what else our scheme might be trying to do.


We still haven’t addressed the OP except in my flat “no”. I was kind of hoping for your sake that one of the smart-a...er...folks around here would prove me wrong via some elegantly genius thing, but I’m afraid in this case you’ve got too many things trying to connect to other things without quite enough lugs to keep them all separate. So then the question is “Why?” What exactly are you trying to accomplish? Is the smaller cap actually better for the way you intend to use the split coil? Is the bigger cap actually important for the HB? Neither one matters much at all until the T pot is way down anyway, and if you’re never going to roll it way off...

[frets]

Sorry Ash😺

[col]

frets, is an S-1 switch a viable option?

[Yogi B]

Aug 5, 2021 11:04:21 GMT -5 ashcatlt said:

We still haven’t addressed the OP except in my flat “no”. I was kind of hoping for your sake that one of the smart-a...er...folks around here would prove me wrong via some elegantly genius thing, but I’m afraid in this case you’ve got too many things trying to connect to other things without quite enough lugs to keep them all separate. So then the question is “Why?” What exactly are you trying to accomplish? Is the smaller bigger cap actually better for the way you intend to use the split coil? Is the bigger smaller cap actually important for the HB? Neither one matters much at all until the T pot is way down anyway, and if you’re never going to roll it way off...

It's a shame we don't want it the other way around (as you originally wrote), because the exact opposite of what frets would like (a larger capacitance with the full HBs) is definitely possible. As shown in what are also my answers to the initial question:

In the top diagram: unsplit, C2 is shunted to ground thus leaving only C1, 47nF; when split, both caps are in series giving approx. 22nF.

In the lower diagram: unsplit, C3 & C4 are in parallel giving a total of 47nF; split, C4 is disconnected from ground leaving only C3, 22nF.

[Deleted]

If you can show what you want in each state without switches in it
From pickup to where it joins selection switch

Can just work from there

Im miss reading things:(