Do Pickup Covers Degrade The Sound?

[vpcnk]

the pickups pick the sound from the strings, right?

so if you have a piece/sheet of metal (the pickup cover) between them and the strings would it not obstruct the communication between the pickup and the strings?

am i right in this?

also i read somewhere the silver (plated?) pickup covers are better than nickel etc in terms of allowing the pickup to pickup the sound from the strings. how true is this?

appreciate the feedback.

[Channelman]

If the piece of metal between the magnetic pickup and the string is non-magnetic then the

'communication' between the string and pickup will not be affected.

But, and this is only my opinion, the outer ring of the pickup cover and to some extent the

rest of the cover will act like a 'shorted turn' since, whilst it may not be magnetic, it

will still conduct electricity.

This 'shorted turn' on the pickup winding will reduce the 'Q' of the pickup and any 'resonances'

due to its inductance and self capacitance.

So it will sound different.

Channelman

[vpcnk]

if a metal pickup cover due to its natural quality (hardness, thickness) etc is a hindrance, how about a cover of other materials?

strat pickup covers seem to be plastic/nylon?

emg pickup covers seem to be plastic?

any ideas/suggestions of these?

my specific area of interest is humbucker covers.

[Prostheta]

Plastics on the whole tend to be non-conductive so will be magnetically and electrically transparent. In theory, you could mount pickups from the rear of an instrument and have them hidden under the top wood as long as the strings were in the magnetic field.

I'm curious like you though - would the marginal water content of wood affect tone if used as covers? I suspect not, as the water content of air should be almost the same as stable wood anyway :-)

This might deserve a different thread a la the sustainers, but would this "shorted turn" stuff mean mean you could also manipulate the magnetic field and tonality of a pickup using a wire coil wound around a cover and electrical signals?

Edited September 20, 2006 by Prostheta

[Robert_the_damned]

as you see this is a bit of a debated subject.

Its my personal opinion that the biggest effect a cover on the pickup has (at least on a humbucker) is that it means you can't get the pickup as close to the strings. Obviously a plastic pickup cover wont have any effect beyond what I've just mentioned. As for metal covers I'm not sure...its possible that as they're grounded they could act in some way to affect the tone but I don't think this would be at all detectable by ear

If you want to go for covers then its possible you might need a slightly higher output pickup (to compensate for the fact your pickup will have to be slightly further away from the strings) but I don't think you'd really be able to notice it to be honnest.

covers look cooler anyway

Robert

[Prostheta]

The exact question was in regards to covers degrading the sound per se, which I don't think they do in the slightest. Modifying perhaps, but not worsening it! A squillions Tele's can't be wrong when it comes to magnetically-inclined stuff in the pickups field of vision :-) As you say Robert, the physical impact of something between the pup and the strings MAY do, but not in the way of degradation.

[vpcnk]

in harmony central, for gibson 490r humbucker reviews, one reviewer notes as to how the sound totally opened up when he removed the pickup covers.

[Setch]

Yes, but that's one, anecdotal account, on a website which has a solid gold reputation for perpetuating myths as fact.

They may change the sound fractionally, but they don't hurt it. If you really want to find out, try a pickup with and without a cover, and see what you hear. The smart money says 'very little'.

[mammoth guitars]

When talking with a major pickup manufacturer they stated when a pickup is designed with a cover, design compensation is added so the pickup will sound like an uncovered one.

That being said I doubt the Asian built pickups go that far in their design.

[JoeAArthur]

Metal covers do affect the sound, although I don't think I could say that it is degraded.

The metal cover, when grounded as most of them are due to contact with the metal baseplate, form one plate of a capacitor. The coil windings form the other capacitor plate.

This capacitance does reduce the resonant peak, leading to a slightly reduced treble sound with the cover.

Can you notice it? Maybe, but I doubt it. Although the plate-to-plate area may be large, the distance between them is relatively more and probably won't result in much capacitance - at best it would be measured in pico-farads and I would think that 100pf would be the upper value - it all depends on the physical construction of the pickup.

Personally, I think the additional shielding benefits from electrostatic sources more than outweigh the slight reduction in treble.

[custom22]

They do effect the sound. Paul Reed Smith (the person) refuses to do chrome plating on his Dragons because of this. The plate sort of shields it, and gives a warmer tone, whereas noncovered ones are brighter generally.

[spazzyone]

Think about the history of the humbucker and Seth Lover's Patent

the original thinking was not based on tone or power

it was noise cancelation. and humbuckers for years were based of this principle

there is usualy one dominet coil (screw polpeice) and one "dummy coil" (slug polpeice)

the cover further acted as a sheild and the screws protruted through this cover

to better pickup the vibration of the strings. but the dummy coil still colored the tone

(just like a capacitor) and a minor increase in power (biproduct)of the twin coils

enter the after market and the focus shifted to power(Super Distortion's) and others.

wich used both coils (no covers) to produce more power resulting in(higher mids)

now we are back full circle sort of (virtual vintage). one "active"coil one dummy coil

to obtain that single coil sound with no noise

so does a cover affect tone? that answer would be Yes

but most people would not notice it in a blind test

as far as PRS himself i read this in a guitar world interveiw for his 20th anniversery

to qoute Mark Quigley of PRS guitars

"on a hearing scale there are normal humans, then dogs, then Paul.

design and build for over twenty years and you too would be like him

[blackburncustomguitars]

the pickups pick the sound from the strings, right?

so if you have a piece/sheet of metal (the pickup cover) between them and the strings would it not obstruct the communication between the pickup and the strings?

am i right in this?

also i read somewhere the silver (plated?) pickup covers are better than nickel etc in terms of allowing the pickup to pickup the sound from the strings. how true is this?

appreciate the feedback.

Hi,

There is so much voodoo/hoodoo on this! The cover will VERY slightly attenuate the sound, but not in a bad way. C'mon guys, cut the crap here!

Peace,

Dave

[psw]

C'mon guys, cut the crap here!

Oh no...I think it is worth debating and all the responses have been great and right on the mark...

There will be a very slight difference due to capacitance and eddy currents...but is this difference very noticable (no not really) and is this a bad thing (not necessarily)...so great replies from the guys at project guitar as always...

there is usualy one dominet coil (screw polpeice) and one "dummy coil" (slug polpeice)

the cover further acted as a sheild and the screws protruted through this cover

to better pickup the vibration of the strings. but the dummy coil still colored the tone

(just like a capacitor) and a minor increase in power (biproduct)of the twin coils

enter the after market and the focus shifted to power(Super Distortion's) and others.

wich used both coils (no covers) to produce more power resulting in(higher mids)

now we are back full circle sort of (virtual vintage). one "active"coil one dummy coil

to obtain that single coil sound with no noise

This is not entirely true...the cover's completed the product and the screw poles apparently were included because the marketing team wanted something extra to adjust (it wasn't an important part of the design)...so chrome and things to play with rule again! As for the dummy coil, ...no the other coil is just as effective as the screw poles...possibly more so (more mass in the slug poles)...so it is no dummy. A dummy would be if you removed the slugs making it effectively a single coil with a dummy alongside it...would sound like a split and be a bit weak though with a standard humbucker...

Its my personal opinion that the biggest effect a cover on the pickup has (at least on a humbucker) is that it means you can't get the pickup as close to the strings.

This has far the most influence over the sound and power of a pickup! Right on!

This might deserve a different thread a la the sustainers...

Now that's funny!

I actually got side tracked into the sustainers...originally I was intereted in producing some new kinds of pickups...maybe I will...

I was looking into a design with rare earth magnets that could be adjusted within the coil (so the magnets could move)...and tooled aluminium bobbins that looked like they came off a motorcycle...very cool, future/retro chic...you could see the coils through holes in the bobbin and all!!!

Now...metal is not used for this purpose for various reasons...but, does it really make it a bad thing if it effects the tone of a device...not if it does it in a way that is good to your ears, and it is designed to be made and sound that way...

Personally...my LP has exposed coils and metal surrounds...go figure, I like the look...and that is what it is mostly about I suspect...

pete

[spazzyone]

Pete you are totaly correct

I just phrased what i was saying wrong

first no its not a tru dummy coil but its intention was to reduce hum

not to increase power or color the tone (Biproduct)

and because of the cover the screws can read the strings better

than the slugs and even more so if the pickup was poted

in which case there would be wax between the slugs and cover

which would make the screws the domminet coil as it can get

closer to the strings

any how thats how it should have read if i was thinking better

sorry all

[Jozer99]

Its a complicated subject, and almost a matter of opinion more than science. Putting anything that is dimagnetic (what we consider non-magnetic) between the pickup and the strings shouldn't effect the sound. However, nothing is completely non-magnetic, everything will effect the field weakly. This effect would be to make the field weaker and less concentrated, which would lead to a "mellower" sound. This effect should be so small as to be unnoticeable, but various people have insisted that they can hear the difference. Notably, the trend was started by Jimmy Page, who took the covers off the PAFs in his Les Paul, and claimed that it gave him his unique sound (although he had many more modifications to his pickups like custom winding and a coil shunt).

However, putting something ferromagnetic (iron, steel, etc) between the pickup and the strings, or even NEAR the pickup and the strings will drastically change the magnetic pattern and probably the sound. This could make the pickup weaker, or stronger, depending on what is used, and where.

Another thing that having a cover does is to insulate the pickup from noise. A metal (not plastic) cover acts as a Faraday cage, and intercepts most of the electric hum coming from the environment. A pickup with a cover should have less hum, although with a humbucker the difference shouldn't be much.

A metal cover will very slightly increase the capacitance of the pickup. I can't imagine this being much of an issue, but I suppose it could change the sound a bit.

Lastly, a cover will help protect the pickup from the environment. This can be a good or a bad thing. The more the pickup is exposed, the faster it will "age", or get mellower as the wire corrodes slightly. On the other hand, it will be more protected from being hit, soaked with water/sweat, and therefore may be less likely to break.

Hope this clarifies the issue a little bit.