Has Anybody Ever Seen This Mod?

[Mossman]

Sometimes I don't know when to quit, and I found myself still digging around the internet looking for Casino P90 covers when I came upon this on TDPRI:




https://www.tdpri.com/threads/cover-tec ... er.682875/

It was posted by this engineer type named Ken Willmott in 2016. It prevents eddy current loss and makes a Tele neck pickup sound like it doesn't have a cover. He was looking for advice on manufacturing when he posted this, and I wondered if there was anyone here who can make cuts like this in a metal pickup cover? The cuts do not have to be as wide as they are in that illustration. In fact, the thinner the cuts, the better. The whole purpose is to get the sound of an uncovered pickup while preserving the traditional look.

At first I thought of @Floridian FX, but you can't use a laser on chrome. I don't know if Ryan has other precision cutting equipment at his disposal, or if he'd even be interested in doing it, but I thought I'd put it out there. The only thing that I could do myself is use a Dremel with a cutting disk, but I can tell you from experience, that won't look anything close to clean, or straight, and the cuts will be very noticeable, defeating the whole purpose of the mod.

Here's his technical article, for anyone who's interested: https://kenwillmott.com/blog/wp-content ... ometry.pdf

And the shorter, non-technical version: https://kenwillmott.com/blog/archives/246

He's got a design for humbuckers too, but still, the cuts are too wide:

[toomanycats]

While the science behind this is of interest to me, considered from an aesthetic perspective I believe that those slits on the pickup cover would feel just as "untraditional" as having no cover at all.

From 10-20 ft away, in front of the stage, somebody probably wouldn't be able to see the cuts, though what matters is that I would know they're there!

Isn't it funny how we wrestle in our own minds with the idea of what's "authentic," "traditional," and "classic," whether it's the subtle curves of a headstock, the exact hue of amber knobs, and other minute details, all the while knowing full well that the public can scarcely distinguish between a Tele and a Les Paul?

[mickey]

Seems to me like Mr. Willmott has too much time on his hands.

[mozz]

Cnc machine could do it. I think you would need to have a 2 wire pickup. If the cover was grounded it wouldn't matter how many slits it had. Myself, I would use a sharpie and a Dremel.

[BatUtilityBelt]

A CNC mill could do the cuts, but it sounds like they would be far too wide for your preferences. Even the smallest of end mills would cut at least as wide as the tele neck picture example, and could not get as narrow as the humbucker pictured. To make the turn down the middle of the tele cover would take a 5 axis mill because otherwise the depth of that cut for a tiny end mill would break the mill for sure.

I suspect the humbucker was done with a circular blade (probably table saw, but still I'm still guessing). A water jet could pull off a much narrower cut than either, but I think that would have to be on flat pieces before they were bent.

[Mossman]

While the science behind this is of interest to me, considered from an aesthetic perspective I believe that those slits on the pickup cover would feel just as "untraditional" as having no cover at all.

From 10-20 ft away, in front of the stage, somebody probably wouldn't be able to see the cuts, though what matters is that I would know they're there!

Isn't it funny how we wrestle in our own minds with the idea of what's "authentic," "traditional," and "classic," whether it's the subtle curves of a headstock, the exact hue of amber knobs, and other minute details, all the while knowing full well that the public can scarcely distinguish between a Tele and a Les Paul?

Cnc machine could do it. I think you would need to have a 2 wire pickup. If the cover was grounded it wouldn't matter how many slits it had. Myself, I would use a sharpie and a Dremel.

As I mentioned in my previous post; you would want to make the cuts super-fine, so as not to be seen. The prototypes that he made were for proof of concept, they're not the finished product. I can't argue any of this on a technical level. I know very little about eddy currents, or whether grounding the cover would or would not negate any effects, but I did link all the pertinent data if you want to learn more. This is a tested concept. I doubt Willmott would have been seeking to refine it if it didn't work. He's putting this out in the public domain, so it's not like he's trying to make money off of it, or scam people with technical mumbo-jumbo.

Personally, I have no need of this mod. I'm not an aesthetic purist. I have a Tele that's had a coverless neck pickup for 14 years and it doesn't bother me in the least. Sure, I'd like to keep the cover on my '50s Tele, but that pickup sounds good with the cover on. Never thought about taking it off. The rest of my Teles have non-Tele pickups... That's how much of a traditionalist I am. I enjoy the classic Tele aesthetic, but I don't consider it inviolate. I just found this interesting, and thought some of y'all might find this interesting too.

Seems to me like Mr. Willmott has too much time on his hands.

Why do you say that? Did Seth Lover have too much time on his hands when he set out to design the humbucker? Or was he trying to solve a problem? This may not be a problem that you or I need solving, but that doesn't make it of no interest to anybody. I'm sure there were plenty of people back in the '50s who thought P90s were just fine, and any attempt to improve on them was just a waste of time. We'd still be riding around on horses with that kind of thinking!

Of course, I can find it a little hard to argue that wouldn't be better.

[Mossman]

A CNC mill could do the cuts, but it sounds like they would be far too wide for your preferences. Even the smallest of end mills would cut at least as wide as the tele neck picture example, and could not get as narrow as the humbucker pictured. To make the turn down the middle of the tele cover would take a 5 axis mill because otherwise the depth of that cut for a tiny end mill would break the mill for sure.

I suspect the humbucker was done with a circular blade (probably table saw, but still I'm still guessing). A water jet could pull off a much narrower cut than either, but I think that would have to be on flat pieces before they were bent.

Yeah, I think the consensus in the TDPRI thread was that a water jet would probably be the best option. I wasn't aware that it couldn't cut around corners, though. That wouldn't present a problem for the humbucker covers, as the slots only have to extend from pole-piece to pole-piece. They don't have to go all the way to the edge of the cover. He used a Dremel to make the cuts, and I think it was just easier to go all the way across with it, but the vertical slot on the Tele cover does have to go all the way to the bottom. I think it would be problematic to make the cuts first, and then stamp the metal into shape. The slots would open and distort under the stress.

[Mossman]

Isn't it funny how we wrestle in our own minds with the idea of what's "authentic," "traditional," and "classic," whether it's the subtle curves of a headstock, the exact hue of amber knobs, and other minute details, all the while knowing full well that the public can scarcely distinguish between a Tele and a Les Paul?

Yeah, like if the Moderne became wildly popular and iconic, we'd be cringing at guitars that don't look like Gumby.

And most of the public can scarcely distinguish a guitar from a bass, let alone know the model names. Those that do are very proud of their knowledge, though they get half of it wrong... Those people work at Guitar Center.

[Floridian FX]

How tall is the Pickup Cover? Ideally it would be a 1 setup cnc option.

[Mossman]

How tall is the Pickup Cover? Ideally it would be a 1 setup cnc option.

I don' have one on hand to measure, but I would guess it's about 7/8" including the tabs on the bottom. It's definitely less than an inch.

How fine could you make the cuts with CNC?

[Floridian FX]

How tall is the Pickup Cover? Ideally it would be a 1 setup cnc option.

I don' have one on hand to measure, but I would guess it's about 7/8" including the tabs on the bottom. It's definitely less than an inch.

How fine could you make the cuts with CNC?

I could go as small as .020", but the one going down to the bottom of the cover would have to be a secondary operation, I can only get 10x length of tool.

[tonebender]

A series of very small holes across the length of the top may work. They make drill bits for metal as small as .013".

[Mossman]

A series of very small holes across the length of the top may work. They make drill bits for metal as small as .013".

I think if that would work, then these would work... and they don't.



This guy didn't come across that configuration of cuts randomly. There's something about the geometry that affects the eddy currents in such a way as to not lose treble. But I'm starting to see why he gave up on it.

[BatUtilityBelt]

I could go as small as .020", but the one going down to the bottom of the cover would have to be a secondary operation, I can only get 10x length of tool.

Yup. And the smaller the mill, the slower the work. It is soooo easy to snap a tiny diameter end mill, even going slow, because of chatter. There are diminishing returns with small diameters.

[Spike]

If you can find someone with a wire EDM, you can get down to .010" - .012" width, but there might be bit of discoloration of the chrome.

[andrewsrea]

The two effects of eddy current that I know of in a pickup are 1.) being more prone to capacitance (high frequencies passing to ground) when turning your volume down (i.e.: treble volume drops faster than mid and low frequencies) and 2.) spurious noise (in that order).

First, I've never heard of eddy current loss in a Telly neck pick up cover. I cannot imagine it, since eddy currents are the results of small voltage potential differences across the mass. Traditional covers are nickel or nickel-plated brass which is resistant to eddy currents if grounded properly. Next, they are low mass relative to the inductance and magnetism and connected to ground. If currents exist, it has to be an insignificant component of the final signal.

Covered humbuckers with copper baseplates experience some eddy current, because of the copper and the magnetism being directly coupled with the baseplate (especially with Alnico, which is also conductive). Telly baseplates (bobbins) are non-conductive and neither they nor the magnets are meant to be coupled to the cover.

IMHO this is interesting theory and experiment, but will not have a magic impact on tone.

Note that all metal covers are prone to treble leak (capacitance), which is a function of mass and proximity to the coil windings. This is why coverless pickups sound brighter. Even the 'faceless' covers still exhibit practically the same effect on the highs as a full cover (which is why I am not a proponent of copper shielding, unless you are good with the reduction in trebles). Covers can also change the inductance and resonant frequency of the pickup, depending on the composition.

So even from a non-eddy current aspect, I don't believe the concept will produce a noticeably better tone.

[mickey]

The two effects of eddy current that I know of in a pickup are 1.) being more prone to capacitance (high frequencies passing to ground) when turning your volume down (i.e.: treble volume drops faster than mid and low frequencies) and 2.) spurious noise (in that order).

First, I've never heard of eddy current loss in a Telly neck pick up cover. I cannot imagine it, since eddy currents are the results of small voltage potential differences across the mass. Traditional covers are nickel or nickel-plated brass which is resistant to eddy currents if grounded properly. Next, they are low mass relative to the inductance and magnetism and connected to ground. If currents exist, it has to be an insignificant component of the final signal.

Covered humbuckers with copper baseplates experience some eddy current, because of the copper and the magnetism being directly coupled with the baseplate (especially with Alnico, which is also conductive). Telly baseplates (bobbins) are non-conductive and neither they nor the magnets are meant to be coupled to the cover.

IMHO this is interesting theory and experiment, but will not have a magic impact on tone.

Note that all metal covers are prone to treble leak (capacitance), which is a function of mass and proximity to the coil windings. This is why coverless pickups sound brighter. Even the 'faceless' covers still exhibit practically the same effect on the highs as a full cover (which is why I am not a proponent of copper shielding, unless you are good with the reduction in trebles). Covers can also change the inductance and resonant frequency of the pickup, depending on the composition.

So even from a non-eddy current aspect, I don't believe the concept will produce a noticeably better tone.

@Mossman this is why I said that I think Mr. Willmott has too much time on his hands.

[Mossman]

First, I've never heard of eddy current loss in a Telly neck pick up cover. I cannot imagine it, since eddy currents are the results of small voltage potential differences across the mass. Traditional covers are nickel or nickel-plated brass which is resistant to eddy currents if grounded properly. Next, they are low mass relative to the inductance and magnetism and connected to ground. If currents exist, it has to be an insignificant component of the final signal.

Covered humbuckers with copper baseplates experience some eddy current, because of the copper and the magnetism being directly coupled with the baseplate (especially with Alnico, which is also conductive). Telly baseplates (bobbins) are non-conductive and neither they nor the magnets are meant to be coupled to the cover.

IMHO this is interesting theory and experiment, but will not have a magic impact on tone.

Note that all metal covers are prone to treble leak (capacitance), which is a function of mass and proximity to the coil windings. This is why coverless pickups sound brighter. Even the 'faceless' covers still exhibit practically the same effect on the highs as a full cover (which is why I am not a proponent of copper shielding, unless you are good with the reduction in trebles). Covers can also change the inductance and resonant frequency of the pickup, depending on the composition.

So even from a non-eddy current aspect, I don't believe the concept will produce a noticeably better tone.

He did mention in his introductory article that the effects would be negligible with nickle-silver covers, but a greater difference could be heard with brass covers. Part of the impetus for this has to do with manufacturing. Brass is cheaper... He even referenced J.R. Butts' Filtertron design, as that came bout as a cost-cutting measure (and why that principle doesn't work with a single-coil pickup).

The other part has to do with the dogmatic stubbornness of "purists". People who will complain about treble loss, but they won't switch to a nickle cover because: "tradition". I guess he imagined that this might an acceptable compromise to them.

I never thought that this was some kind of "magic bullet". It's not something I want to try myself. I don't suffer the neurosis of a purist, and I think my Tele neck pickups sound just fine. I just thought it was interesting, and that some of you all around here who know more about the subject than I do would find it interesting.

BTW, I shield all my guitars and I've never noticed any loss of treble... Just a loss of RF interference.

[Mossman]

The two effects of eddy current that I know of in a pickup are 1.) being more prone to capacitance (high frequencies passing to ground) when turning your volume down (i.e.: treble volume drops faster than mid and low frequencies) and 2.) spurious noise (in that order).

First, I've never heard of eddy current loss in a Telly neck pick up cover. I cannot imagine it, since eddy currents are the results of small voltage potential differences across the mass. Traditional covers are nickel or nickel-plated brass which is resistant to eddy currents if grounded properly. Next, they are low mass relative to the inductance and magnetism and connected to ground. If currents exist, it has to be an insignificant component of the final signal.

Covered humbuckers with copper baseplates experience some eddy current, because of the copper and the magnetism being directly coupled with the baseplate (especially with Alnico, which is also conductive). Telly baseplates (bobbins) are non-conductive and neither they nor the magnets are meant to be coupled to the cover.

IMHO this is interesting theory and experiment, but will not have a magic impact on tone.

Note that all metal covers are prone to treble leak (capacitance), which is a function of mass and proximity to the coil windings. This is why coverless pickups sound brighter. Even the 'faceless' covers still exhibit practically the same effect on the highs as a full cover (which is why I am not a proponent of copper shielding, unless you are good with the reduction in trebles). Covers can also change the inductance and resonant frequency of the pickup, depending on the composition.

So even from a non-eddy current aspect, I don't believe the concept will produce a noticeably better tone.

@Mossman this is why I said that I think Mr. Willmott has too much time on his hands.

Then why didn't you say that?

[mickey]

The two effects of eddy current that I know of in a pickup are 1.) being more prone to capacitance (high frequencies passing to ground) when turning your volume down (i.e.: treble volume drops faster than mid and low frequencies) and 2.) spurious noise (in that order).

First, I've never heard of eddy current loss in a Telly neck pick up cover. I cannot imagine it, since eddy currents are the results of small voltage potential differences across the mass. Traditional covers are nickel or nickel-plated brass which is resistant to eddy currents if grounded properly. Next, they are low mass relative to the inductance and magnetism and connected to ground. If currents exist, it has to be an insignificant component of the final signal.

Covered humbuckers with copper baseplates experience some eddy current, because of the copper and the magnetism being directly coupled with the baseplate (especially with Alnico, which is also conductive). Telly baseplates (bobbins) are non-conductive and neither they nor the magnets are meant to be coupled to the cover.

IMHO this is interesting theory and experiment, but will not have a magic impact on tone.

Note that all metal covers are prone to treble leak (capacitance), which is a function of mass and proximity to the coil windings. This is why coverless pickups sound brighter. Even the 'faceless' covers still exhibit practically the same effect on the highs as a full cover (which is why I am not a proponent of copper shielding, unless you are good with the reduction in trebles). Covers can also change the inductance and resonant frequency of the pickup, depending on the composition.

So even from a non-eddy current aspect, I don't believe the concept will produce a noticeably better tone.

@Mossman this is why I said that I think Mr. Willmott has too much time on his hands.

Then why didn't you say that?

Because I knew that if I waited Rob would come along and explain it better than I could.

[andrewsrea]

Not to say eddy currents aren't a concern and fixable.

Many early Dimarzios and a ton of Epiphone pickups use copper baseplates.

I have a 2010 Epiphone Les Paul Custom Classic that had a great sound with the volume on '10.' The bridge is A5 at about 12K and the neck is A5 at about 8.5K (a little beefy). Oh yes - very conductive gold slugs and polepieces, I am a volume knob abuser and this guitar suffered from the trebles getting very dark when you came off of '10,' which was not working for me.

I thought about approaching the problem by using a treble bleed or even just winding my own pups. As an experiment, I swapped out the baseplate for an American made original PAF spec nickel-silver baseplate. Problem solved. it now behaves very well and I play it in regularity.