APH-1 Rotation

[Butch Snyder]

I have an APH-1 (Alnico 2 Pro Humbucker) in the neck position of one of my guitars. Without actually doing it myself first, what would the tone difference be if I rotate it so the slug coil is toward the neck?

 

[Rex_Rocker]

The A2P is symmetrically wound. The difference should be very subtle if you rotate it. The slug coil tends to be stronger on screw/slug humbuckers, but the screw coil is always a tiny tiny bit closer to the strings normally. So most people here are going to tell you the difference is pretty negligible.

 

[Mincer]

Yeah, I've done this, and after I flipped it and tuned up, it sounded so close to the other 'right' way that it didn't seem worth doing. It does remain my favorite pickup of all time, though.

 

[Butch Snyder]

The A2P is symmetrically wound. The difference should be very subtle if you rotate it. The slug coil tends to be stronger on screw/slug humbuckers, but the screw coil is always a tiny tiny bit closer to the strings normally. So most people here are going to tell you the difference is pretty negligible.

Yeah, I've done this, and after I flipped it and tuned up, it sounded so close to the other 'right' way that it didn't seem worth doing. It does remain my favorite pickup of all time, though.

You guys saved me a bunch of work. Thanks a bunch!

 

[jeremy]

there is a difference, but its pretty subtle

 

[Aceman]

Nothing, unless you are gonna really change the poles/height etc.

 

[Spaghetti Bolo]

Slight tonal difference BUT feels different to play. Normal rotation is softer.

 

[Butch Snyder]

Mike Stern is a pretty big influence of mine. I have noticed that he has always had an SH-1 in the neck of his guitars; whether his Yamaha or homemade one that was given to him. His neck pickup is always flipped.

 

[ehdwuld]

I find when split
the slugs are slightly warmer than the screws

I like the slug coil split sound personally

Can't see it making much difference when the pickup still still humbucking

 

[freefrog]

What others said: there's a small difference. The coil with slugs is brighter than the other in a Gibson style HB (inherently, location under the strings aside), while the slightly darker coil with screws tends to be louder for various reasons : less eddy currents and generally more distance from the strings for the coil with slugs, more eddy currents and inductance from the coil with screws.

But this difference is subtle. Here is an example, FWIW:

https://youtu.be/r9L8om-TXIo?si=ALO8Bcuu-M4nwJdY&t=195

 

[ehdwuld]

What others said: there's a small difference. The coil with slugs is brighter than the other in a Gibson style HB (inherently, location under the strings aside), while the slightly darker coil with screws tends to be louder for various reasons : less eddy currents and generally more distance from the strings for the coil with slugs, more eddy currents and inductance from the coil with screws.

But this difference is subtle. Here is an example, FWIW:

https://youtu.be/r9L8om-TXIo?si=ALO8Bcuu-M4nwJdY&t=195

I'm sorry but my experience was the opposite
with the screws brighter and the slug coil slightly warmer.

Weird

 

[freefrog]

I'm sorry but my experience was the opposite
with the screws brighter and the slug coil slightly warmer.

Weird

I'm also sorry to annoy potential readers with the longer answer below...

A parenthesis in my previous post states that location under the strings was left aside in my explanation. This location causes a comb filtering effect of harmonics changing with the scale AND notes. The Tillman applet that I've shared here dozens of times illustrates that: https://till.com/articles/PickupResponseDemo/index.html
So each coil "comb filters" the sound in a slightly different way.

There's also potentially a capacitive mismatching between coils with 4-conductors cables: it depends on the lenght of the cable and with which inner conductor the naked ground wire is finally connected... I've devoted a long topic to this question on the music-electronics forum, with a boatload of experimental screenshots collected by our lab gear.

Furthermore, louder is often felt as brighter and the coils with screws are often louder because closer to the strings (because of their settings or/and of the angle of the pickups).

Oh, and... if a low carbon alloy is used for the slugs vs a high carbon alloy for the screw poles, it might change the tone too, of course. ;-)

These random factors interact with the sound, potentially or factually, and might make that a coil with screw poles is felt as brighter.

But basically, in a typical Gibson style humbucker, the coil with slugs IS brighter: shorter magnetic poles are more efficient, with less Foucault currents and inductance.

It's possible to brigthen a coil with screws : clipping these poles will do that, by decreasing the inductance and eddy currents.

Below is a screenshot of electrically induced response on a typical 2 conductors symetrically wound Gibson style HB, up to 20khz. Each vertical steps measures 10dB. Resonant peaks have been aligned. The coil with screws is still louder before resonant peak and darker beyond it, VS the coil with slugs.

All that being said: have you listened the example that I've shared and what did you hear?

 

[Spaghetti Bolo]

I have a pair of Customs in my pickup drawer, so I made set of double slug and double screw Customs recently. I loaded them with A4 as its on the edgier side. Playing these really helps demonstrate the tonal and response/feel difference between the slug and screw coils. With this particular A4, in this particular guitar, in this particular pickup location, I greatly preferred the double screw.

 

[Teleplayer]

AFAIK, the screw poles have brighter tone. I believe it is due to alloy steel used for screws having worse electrical conductivity than the slugs. Lower conductivity -> lower eddy current loss -> brighter top end.

As a seperate issue, the screw pole may have less magnetic permeability so the screw coil will have lower inductance which potentially contributes to brighter tone as well.

 

[freefrog]

AFAIK, the screw poles have brighter tone. I believe it is due to alloy steel used for screws having worse electrical conductivity than the slugs. Lower conductivity -> lower eddy current loss -> brighter top end.

As a seperate issue, the screw pole may have less magnetic permeability so the screw coil will have lower inductance which potentially contributes to brighter tone as well.

I won't say that "my experience is the opposite" : I'll just state again that our experiments seem to prove the contrary as illustrated in post 12 [whose wording was not optimal because it lacked of relativistic nuance: sorry for that, fellow members].

Screw poles pass not only through the baseplate but also through a keeper bar, contributing to explain the higher Foucault currents on this side.

I lack of time this morning to check our data about electrical conductivity and magnetic permeability of alloys typically used for slugs / screws but I'll try to share about that later, if time permits.

That being said to clarify my statements above and not to argue. I'll certainly read with interest any experimental testimonial showing different results. ;-)

 

[Teleplayer]

In post 12, it states "The resonant peaks have been aligned". If you did not align them, do you think it could show the screw pole has a higher Q factor of resonance?

When I say "brighter tone", I am thinking about the pickup resonance frequency and 'Q' factor. I'm unsure how the high frequency harmonics relate to the percieved tone - It might not be the determining factor in this case.

Rather then looking at permeability data, I think it would be sufficient to just know the inductance resulting from a given number of turns.

 

[ehdwuld]

We can agree to disagree on the tone of screw coils

if one experience is true for that listener

That doesn't make the inverse false

Just the variation in the human experience

Like not everyone likes the sound of Ace's solos
some liked Vinnie's
some liked Bruce's
or that other guy that lived with his parents and died

Some like DLR
Some think Sammy was Better

Doesn't matter

 

[freefrog]

if one experience is true for that listener

That doesn't make the inverse false

Just the variation in the human experience

Agreed.

I think that my post 12 was taking in account your experience by trying to explain it.

And the end of this post was just meant to explain the reasons behind my own previous statements - although reading it again made me realize it doesn't sound like that. :-/

It would be great if the tone of our voice was there to convey the intention and mood behind our posts. All we have are emoticons... ;-)

 

[freefrog]

In post 12, it states "The resonant peaks have been aligned". If you did not align them, do you think it could show the screw pole has a higher Q factor of resonance?

Below is what a quick research in my archives gave me: crude resonant peaks of a Gibson 496R, on a linear scale from 1 to 20khz, without alignment of respective levels. I've added a zoom on these peaks just under them.

Not that it matters: again the goal is to contextualize my past statements, FWIW. ​

 

[Teleplayer]

Thanks for your graphs, freefrog. I will definitely keep an open mind on this. What you wrote about the keeper bar contributing to higher foucault currents is a good point.