Unbalanced humbuckers in parallel?

[sumitagarwal]

I know people say the P-Rails, with very different coils, sound better in parallel than most humbuckers so it got me thinking: what about other unbalanced humbucker designs like, say, the C5/59?

Is the stronger coil more dominant in series or in parallel wiring?

 

[freefrog]

The "stronger" coil (the one with the higher inductance) should be louder in both cases, so the pickup shouldn't sound the same if the "screw coils" is closer to the neck or to the bridge - which makes a difference with "normal" humbuckers as well, anyway.

BUT the core of the tone should still be due to the main resonant peak of both coils working together, in series as well as in parallel.

Beyond this main resonant peak, an "unbalanced" humbucker in series should exhibit secondary peaks and dips, interacting more or less with the harmonic comb filtering due to the location of the pickup. Like DiMarzio Dual-Resonance models, but with a more drastic effect, not necessarily desirable if the pickup is wired unproperly (putting the ground on the slugs coil side won't make the pickup react in the same way than if the screws coil is grounded and the magnet flipped, for questions of parasitic capacitance having a "double-tuning" effect... and it's not necessarily a good thing for harmonic richness).

In parallel, an "unbalanced" HB would have an "hybrid" inductance, not especially interesting. For instance, a CS/59 hybrid should measure around 1.5H. It's better for parallel wiring than the tiny inductance of a 59 in parallel but it's still not quite as usable than the Fender alike inductance of a "balanced" normal Custom HB...

If people like P-Rails in parallel , it's because of the specs involved: more than 10H of inductance in series if memory serves me (which is really high, in the DiMarzio X2N range) and something like 2.6H in parallel... which is the inductance of a SSL1.

NOTE - A funny thing is that in DiMarzio Dual-Resonance pickups, the coil with the highest resistance is not the louder... Having the same number of turns, both coils have similar inductances, so the one with the highest DCR reading is quieter, precisely because it's the more resistive.
That being said to recall how counter-intuitive guitar pickups can be.

 

[sumitagarwal]

The "stronger" coil (the one with the higher inductance) should be louder in both cases, so the pickup shouldn't sound the same if the "screw coils" is closer to the neck or to the bridge - which makes a difference with "normal" humbuckers as well, anyway.

BUT the core of the tone should still be due to the main resonant peak of both coils working together, in series as well as in parallel.

Beyond this main resonant peak, an "unbalanced" humbucker in series should exhibit secondary peaks and dips, interacting more or less with the harmonic comb filtering due to the location of the pickup. Like DiMarzio Dual-Resonance models, but with a more drastic effect, not necessarily desirable if the pickup is wired unproperly (putting the ground on the slugs coil side won't make the pickup react in the same way than if the screws coil is grounded and the magnet flipped, for questions of parasitic capacitance having a "double-tuning" effect... and it's not necessarily a good thing for harmonic richness).

In parallel, an "unbalanced" HB would have an "hybrid" inductance, not especially interesting. For instance, a CS/59 hybrid should measure around 1.5H. It's better for parallel wiring than the tiny inductance of a 59 in parallel but it's still not quite as usable than the Fender alike inductance of a "balanced" normal Custom HB...

If people like P-Rails in parallel , it's because of the specs involved: more than 10H of inductance in series if memory serves me (which is really high, in the DiMarzio X2N range) and something like 2.6H in parallel... which is the inductance of a SSL1.

NOTE - A funny thing is that in DiMarzio Dual-Resonance pickups, the coil with the highest resistance is not the louder... Having the same number of turns, both coils have similar inductances, so the one with the highest DCR reading is quieter, precisely because it's the more resistive.
That being said to recall how counter-intuitive guitar pickups can be.

That's a whole lotta insight packed into a single post. Really helpful, and honestly these insights are useful well beyond the question of parallel wiring unbalanced humbuckers!

 

[freefrog]

That's a whole lotta insight packed into a single post. Really helpful, and honestly these insights are useful well beyond the question of parallel wiring unbalanced humbuckers!

Thx. Always glad to share.

While we're at it and as I've seen your question on the guitarnuts2 forum in the topic named "humbucker base plate and eddy currents" : yes plastic baseplates are possible. That's what is found under most Bill Lawrence pickups, precisely because their designer wanted to avoid eddy currents.

And incidentally: my own experimental archives disagree with the idea that eddy currents make no tonal difference because their effect would be under the threshold of perception: granted, Foucault currents shift the amplitude of resonant peaks of a few hz and dB only... but they have other potential and measurable effects IME: for instance, they can noticeably alter measured harmonic distortion and intermodulation distortion (of clearly more in some cases than the supposed perception threshold of 3dB).

FWIW: an honest sum up of the results obtained here, through lab tests of another kind than on guitarnuts...

 

[sumitagarwal]

Thx. Always glad to share.

While we're at it and as I've seen your question on the guitarnuts2 forum in the topic named "humbucker base plate and eddy currents" : yes plastic baseplates are possible. That's what is found under most Bill Lawrence pickups, precisely because their designer wanted to avoid eddy currents.

And incidentally: my own experimental archives disagree with the idea that eddy currents make no tonal difference because their effect would be under the threshold of perception: granted, Foucault currents shift the amplitude of resonant peaks of a few hz and dB only... but they have other potential and measurable effects IME: for instance, they can noticeably alter measured harmonic distortion and intermodulation distortion (of clearly more in some cases than the supposed perception threshold of 3dB).

FWIW: an honest sum up of the results obtained here, through lab tests of another kind than on guitarnuts...

Thanks! That all makes sense to me.

Do you know how accurate the data at guitarpickupdatabase.com is? There they have the PRS SE Paul's pickups (PTP4150 and PTP4151) listed as having nickel silver baseplates, but in listing photos it definitely looks brass to me...

EDIT: Actually, looks like it may have started off nickel silver and changed later? Here are two shots marked VER 10.2019, one with no version number, and one marked VER 10.2021, which looks very different from the earlier ones

But I'd find it surprising that PRS would actively downgrade a key component compared to before, especially as it's becoming more central to their line-up and they're rolling it out into more models where it'll make a bigger impression on the brand reputation

 

[marcello252]

In my experiments I've noticed differences just swapping one coil in a set bridge/neck of the same type, I did it for example with a SD 59 set

 

[sumitagarwal]

In my experiments I've noticed differences just swapping one coil in a set bridge/neck of the same type, I did it for example with a SD 59 set

Yup! I did the same ages ago with a Pearly Gates set, ended up adding brightness. Only problem then is you end up with an equal output neck and bridge pair, where we usually want a hotter bridge. However, apparently PRS has been using unbalanced coils but equal output neck and bridge for their TCI pickups, which is a departure from their earlier pickups. So maybe there's something to that approach.

 

[freefrog]

Thanks! That all makes sense to me.

Do you know how accurate the data at guitarpickupdatabase.com is? There they have the PRS SE Paul's pickups (PTP4150 and PTP4151) listed as having nickel silver baseplates, but in listing photos it definitely looks brass to me...

EDIT: Actually, looks like it may have started off nickel silver and changed later? Here are two shots marked VER 10.2019, one with no version number, and one marked VER 10.2021, which looks very different from the earlier ones

But I'd find it surprising that PRS would actively downgrade a key component compared to before, especially as it's becoming more central to their line-up and they're rolling it out into more models where it'll make a bigger impression on the brand reputation

I don't agree with everything I've read on guitarpickupdatabase.com but I've not seen enough of it to tell if I find this site accurate or not (which would appear to me as arrogant anyway: such a hard work so generously shared deserves some respect and carefully weighted comments, IMHO).

In the same way, I've not enough direct experience with PRS pickups to answer about a precise change in the mentioned pickups line... It's easy to find online pics of PRS humbuckers with identically looking brass and/or NS baseplates but it doesn't seem so easy to know why these PU's have been designed like that and/or have changed.

That said, similar changes (that I don't necessarily see as "downgrades") happened with popular pickups from other brands: a recent DiMarzio X2N has a fiberboard baseplate, for example - and doesn't sound like an old one IME.

FWIW. YMMV.

 

[Chistopher]

Yup! I did the same ages ago with a Pearly Gates set, ended up adding brightness. Only problem then is you end up with an equal output neck and bridge pair, where we usually want a hotter bridge. However, apparently PRS has been using unbalanced coils but equal output neck and bridge for their TCI pickups, which is a departure from their earlier pickups. So maybe there's something to that approach.

Magnets could help. I could swapped the neck and bridge pickup in a squier blacktop strat for a friend and kept the ceramic bridge magnet but put an A5 in the neck. Turned out alright, but it was more for experimenting than anything

 

[sumitagarwal]

Magnets could help. I could swapped the neck and bridge pickup in a squier blacktop strat for a friend and kept the ceramic bridge magnet but put an A5 in the neck. Turned out alright, but it was more for experimenting than anything

Yea, I was thinking the same. However, while it'd help with the output levels might that make the tonal balance worse? If you take two pickups of the same winds/coils, and stick a stronger magnet in one and a weaker magnet in the other, won't the one with the weaker magnet sound less bright? And in the neck position for my kind of playing I usually am trying to find ways to increase brightness.

 

[Chistopher]

Weaker magnets aren't always darker, A3 is slightly brighter than A2. In identical pickups I find A4 neck, A8 bridge works well. A3 neck, A2 or UOA5 bridge also works well. Ceramic bridge A5 neck also works well. Or even just putting a thicker magnet in the bridge of the same variety

 

[freefrog]

If you take two pickups of the same winds/coils, and stick a stronger magnet in one and a weaker magnet in the other, won't the one with the weaker magnet sound less bright? And in the neck position for my kind of playing I usually am trying to find ways to increase brightness.

The question was not for me and has already been answered by Christopher but if I can add my POV to the overall perspective: in your previous topic about A4, I was trying to explain that a weaker magnetism flattens the EQing, which doesn't necessarily makes the sound darker... All depends on parms like the Q factor of the resonant peak and on the frequency of this peak, itself linked to the parasitic capacitance of pickup + pots + wiring / cable (non limitative list). A flatter EQing can give the feeling of an extended bandwidth: that's how my friend luthier / winder succeeded to give an "open" tone to his flagship humbucker despite of a super high inductance, theoretically meant to darken the sound...


Beside that, I was also trying to recall that a magnetic alloy does not necessarily imply a defined tone... AlNi3 as used by Gibson in the 40's / 50's has not the same properties than contemporary A3, for instance (ask to James @ Rewind pickups). And several of the A5 magnets listed in my archived data had distinctively different specs : some bar mags exhibit the magnetic field and inductive influence of A5 but make a pickup sound as if they were A2...Same thing with ceramic, which is not always of the same kind... Indox magnets in TarBacks differ compared to the Ceramic 8 mags in a X2N. And the ceramic bars that Gibson uses for 496R are not much stronger IME than a typical A5 bar (this pickup being still dark but for other reasons).

This boring stance being done, let's come back on topic by recalling a popular trick: shorter screw poles make a neck pickup brighter by decreasing inductance and eddy currents, which is still a way to mod the balance between coils... Pulling off the screw poles is even more radical (but diminishes the output and sustain). ;-)

End of my rambling from before the morning coffee. Work is waiting me... Have a nice day, everybody!

 

[sumitagarwal]

The question was not for me and has already been answered by Christopher but if I can add my POV to the overall perspective: in your previous topic about A4, I was trying to explain that a weaker magnetism flattens the EQing, which doesn't necessarily makes the sound darker... All depends on parms like the Q factor of the resonant peak and on the frequency of this peak, itself linked to the parasitic capacitance of pickup + pots + wiring / cable (non limitative list). A flatter EQing can give the feeling of an extended bandwidth: that's how my friend luthier / winder succeeded to give an "open" tone to his flagship humbucker despite of a super high inductance, theoretically meant to darken the sound...


Beside that, I was also trying to recall that a magnetic alloy does not necessarily imply a defined tone... AlNi3 as used by Gibson in the 40's / 50's has not the same properties than contemporary A3, for instance (ask to James @ Rewind pickups). And several of the A5 magnets listed in my archived data had distinctively different specs : some bar mags exhibit the magnetic field and inductive influence of A5 but make a pickup sound as if they were A2...Same thing with ceramic, which is not always of the same kind... Indox magnets in TarBacks differ compared to the Ceramic 8 mags in a X2N. And the ceramic bars that Gibson uses for 496R are not much stronger IME than a typical A5 bar (this pickup being still dark but for other reasons).

This boring stance being done, let's come back on topic by recalling a popular trick: shorter screw poles make a neck pickup brighter by decreasing inductance and eddy currents, which is still a way to mod the balance between coils... Pulling off the screw poles is even more radical (but diminishes the output and sustain). ;-)

End of my rambling from before the morning coffee. Work is waiting me... Have a nice day, everybody!

Another great write-up, and let me see if I can paraphrase to ensure I understand:

1. The stronger the magnet, the more a pickup will sound "like itself" (whatever that "self" sounds like). Reducing magnet strengths in multiple pickups will make them sound more similar (and reduce output)
2. Even with the same classification, different alnico and ceramic magnets will vary in composition and strength. Not referred to in the above reply, but can we largely describe the effect of a given magnet as a combination of it's strength and conductivity, and the composition primarily matters inasmuch as it changes strength and conductivity?
3. Reducing inductance in the neck pickup can help brighten them. By this logic, assuming we keep the existing screw poles, wouldn't the best strategy by to lower the screw poles as far as possible so that we get more of the screw onto the body side of the magnet rather than on the string side of the magnet? Or conversely is it better to extend the screws as far up as possible so they are as far as possible from the magnetic field and have less influence on it?

 

[freefrog]

Another great write-up, and let me see if I can paraphrase to ensure I understand:

1. The stronger the magnet, the more a pickup will sound "like itself" (whatever that "self" sounds like). Reducing magnet strengths in multiple pickups will make them sound more similar (and reduce output)
2. Even with the same classification, different alnico and ceramic magnets will vary in composition and strength. Not referred to in the above reply, but can we largely describe the effect of a given magnet as a combination of it's strength and conductivity, and the composition primarily matters inasmuch as it changes strength and conductivity?
3. Reducing inductance in the neck pickup can help brighten them. By this logic, assuming we keep the existing screw poles, wouldn't the best strategy by to lower the screw poles as far as possible so that we get more of the screw onto the body side of the magnet rather than on the string side of the magnet? Or conversely is it better to extend the screws as far up as possible so they are as far as possible from the magnetic field and have less influence on it?

Hi,
Thx for the kind words. Hasty answer:
1-A weaker magnetism flattening the bandwidth wasn't in my mind a factor of characterless tone... The Strat PU's with the most "personality" among those that I've played are those of a 1962 Strat and happen to be the weakest of all SC's tested with our lab teslameter.
2-Even with the same classification, different alnico and ceramic magnets can (rather than "will", if you don't mind) vary in composition and strength: IME, yes. Not sure to understand what you mean by "conductivity": AlNi(Co) bars are electrically conductive, ferrite bars are not but it has little to do with their tonal influence. Unless you were refering to magnetic permeability ?
3-IMHO and IME, there's no simple answer to your question about screw poles. Screwing them down rises eddy currents / diminishes the inductance of the pickup but also makes the coil with screws slightly weaker than before compared to the slugs coil, which is brighter by location and design (all other parms being equal). Now other factors are to take in account here - like the alloy, size and mass of screw poles, slugs and keeper bar, among others.

These statements are subject to change without notice and will be corrected if I realize to have wrote some misleading or wrong sentence. I personally find difficult to wrap in a few words these falsely simple and deeply synergetic products named guitar pickups (especially when I recall that English is not my mother tongue. LOL). YMMV. HTH nevertheless, within the limitations of my rambling.