Split Coils Talk

[magneticair]

Hello friends👋

The topic with split coils is still not fully disclosed, and let's talk about this constructive solution in this thread.

Many manufacturers do not explain how a split coil pickup located near the neck or in the middle position will work, I mean 3-4 strings on the guitar or 2-3 strings on the bass when you bend. Is there a solution to this problem? Share your opinion, thanks!

[newey]

May 15, 2023 9:23:11 GMT -5 magneticair said:

The topic with split coils is still not fully disclosed

Do you mean a humbucker wired so as to be able to split to a single coil, or are you referring to pickups with a "3x3' pole pieces arrangement such as the Fender Telecaster custom pickups? Or, 2X2 like a P-bass pickup?

I'm assuming you mean the latter. Wouldn't seem like much of an issue on a bass, as bass players typically aren't bending that much. I've never noticed an issue on my P-bass copy. As to guitars, I've never had one with the "3X3" style pickups, so no opinion on that.

[JohnH]

I guess the issue to consider is as you bend a middle string, moving it from over one half to over the other? Say it's a guitar, and there are 2 staggered half coils, one under the top E, B, G, and the other under D, A, low E. So if you bend D, it's moving from over one coil to over the other coil.

Both coils are in phase, so it may be ok. But is there a dip in the signal as you bend, with one coils output falling off as you move the string, before the other picks up?

Is that the issue?

[magneticair]

I study the question more deeply, it is a problem if you often use bands when playing, for example, let's remember such a musician as Billy Sheehan.

In addition to everything described, I noticed that when two pickups with split coils are turned on in parallel, the signal loses a lot of useful timbre and the middle frequencies are weakened. I got this result when I wound 2 split singles for my jazz bass, and each sounds good individually, but in a pair - not the result I wanted. Who can express an opinion on this matter, why is this happening? Thank you!

[magneticair]

May 15, 2023 15:02:14 GMT -5 JohnH said:

I guess the issue to consider is as you bend a middle string, moving it from over one half to over the other? Say it's a guitar, and there are 2 staggered half coils, one under the top E, B, G, and the other under D, A, low E. So if you bend D, it's moving from over one coil to over the other coil.

Both coils are in phase, so it may be ok. But is there a dip in the signal as you bend, with one coils output falling off as you move the string, before the other picks up?

Is that the issue?

I mean a set of pickups, for example, as in the picture: 



By the way, it is interesting how it works on G&L in the stratocaster format:

[ms]

Jul 30, 2023 9:38:39 GMT -5 magneticair said:

In addition to everything described, I noticed that when two pickups with split coils are turned on in parallel, the signal loses a lot of useful timbre and the middle frequencies are weakened. I got this result when I wound 2 split singles for my jazz bass, and each sounds good individually, but in a pair - not the result I wanted. Who can express an opinion on this matter, why is this happening? Thank you!

They have to go in series to have the correct inductance.  If you put them  parallel, the total inductance goes down to less than what it should be and the resonance frequency rises up higher than you want it.  If the resonant frequency is too low with them in series, then you need to use maybe 25% fewer turns on each coil.

[magneticair]

Jul 30, 2023 10:24:28 GMT -5 ms said:

Jul 30, 2023 9:38:39 GMT -5 magneticair said:

In addition to everything described, I noticed that when two pickups with split coils are turned on in parallel, the signal loses a lot of useful timbre and the middle frequencies are weakened. I got this result when I wound 2 split singles for my jazz bass, and each sounds good individually, but in a pair - not the result I wanted. Who can express an opinion on this matter, why is this happening? Thank you!

They have to go in series to have the correct inductance.  If you put them  parallel, the total inductance goes down to less than what it should be and the resonance frequency rises up higher than you want it.  If the resonant frequency is too low with them in series, then you need to use maybe 25% fewer turns on each coil.

Thanks for the answer! Yes, you are right! It is in serial connection that everything sounds as it should. Maybe there is a problem of parallel connection with loss of resonance, adding turns of the coils, will it be possible to compensate?

[ms]

Jul 30, 2023 11:31:50 GMT -5 magneticair said:

Jul 30, 2023 10:24:28 GMT -5 ms said:

They have to go in series to have the correct inductance.  If you put them  parallel, the total inductance goes down to less than what it should be and the resonance frequency rises up higher than you want it.  If the resonant frequency is too low with them in series, then you need to use maybe 25% fewer turns on each coil.

Thanks for the answer! Yes, you are right! It is in serial connection that everything sounds as it should. Maybe there is a problem of parallel connection with loss of resonance, adding turns of the coils, will it be possible to compensate?

Two identical (non-coupled) inductors in parallel have half the inductance of one of them.  You might try adding turns, but what is wrong with a series connection?

[magneticair]

Jul 30, 2023 13:06:04 GMT -5 ms said:

Jul 30, 2023 11:31:50 GMT -5 magneticair said:

Thanks for the answer! Yes, you are right! It is in serial connection that everything sounds as it should. Maybe there is a problem of parallel connection with loss of resonance, adding turns of the coils, will it be possible to compensate?

Two identical (non-coupled) inductors in parallel have half the inductance of one of them.  You might try adding turns, but what is wrong with a series connection?

Serial connection just works correctly, and does not raise questions

[foxmilder]

My apologies if this has been covered already, but Bartolini make a few bass pickups using straight and offset split-coil arrangements — including models with four coils:




I've often wondered whether this design could be feasibly implemented in an electric guitar pickup, ideally in a humbucker-sized casing, offering two noiseless "single coil" voicings in a single pickup and the usual humbucker switching options. Suppose you were to use two distinct designs for the "red" and "blue" coil pairings: alnico poles and vintage output for one "voice"; blades/slugs and higher output for the other. That strikes me as a more obviously useful set of sounds than is normally obtained by complex humbucker switching schemes.

But would it work? The central problem with the "split-coil" class of designs is well-established: they tend to produce undesired cancellation of the signal when strings are bent towards the "seam" between the coils (the cause of which has been discussed in more detail by antigua and ms).

With that problem in mind, my question is this: is a standard humbucker-sized pickup wide enough to sufficiently offset the two halves of a 3+3 split-coil arrangement ("split-coil" referring, in this case, to the arrangement in the first of the above images)?

[magneticair]

Hi all! I can share my own experience in designing split-coil pickups for bass guitars, Precision 51 or Jazz Bass.

If you are not aware, then with any selection of the type of magnets, the magnetic field at the junction of the coils will significantly weaken, which will affect the volume balance between the strings; in other words, strings 1 and 4 on the bass will sound louder and more sensitive than strings 2 and 3. Accordingly, To solve this problem, it is enough to weaken the magnetic field on the rods of the 1st and 4th strings, balancing the sound. It is worth noting that this problem is more pronounced with a vintage neck radius. I hope there is no need to explain how to change the magnetization strength..

In general, you can achieve quite interesting results.

I wonder if anyone can give their opinion on this, maybe there is a more technological solution? Thank you.