Does Copper Shielding affect tone?

[Muckaluck]

Hi guys,

So I was doing some looking around on the effect of copper shielding and some folks say that placing it near or around the pickups will take some of the high end off the tone of your pups. Bill Lawrence talks about Fender using an aluminum plate to take some of the edge off the telecaster pickups here: Bill Lawrence Website

So does that mean if I put copper shielding around my pickup, I will lose some of the edge of the sound?

[Root 5]

It's actually alien transmissions I'm trying to block but...whatever.

[RCCollins]

The BL site you linked to is talking about telecaster guitars, which have a unique bridge-pickup-built-into-the-bridge design for which there is no equivalent in the bass world. The "bridge plate" he's talking about is not just a shielding component. I rather doubt you'll find anything but positive (shielding) effects on your signal if you install a ground plate - but why aluminum? The old Fender Ps used a brass plate, or maybe copper

[mongo2]

You could give it a try and see what happens.

[JLS]

Originally Posted by Muckaluck

Hi guys,

So I was doing some looking around on the effect of copper shielding and some folks say that placing it near or around the pickups will take some of the high end off the tone of your pups. Bill Lawrence talks about Fender using an aluminum plate to take some of the edge off the telecaster pickups here: Bill Lawrence Website

So does that mean if I put copper shielding around my pickup, I will lose some of the edge of the sound?

No.

[Muckaluck]

Originally Posted by RCCollins

The BL site you linked to is talking about telecaster guitars, which have a unique bridge-pickup-built-into-the-bridge design for which there is no equivalent in the bass world. The "bridge plate" he's talking about is not just a shielding component. I rather doubt you'll find anything but positive (shielding) effects on your signal if you install a ground plate - but why aluminum? The old Fender Ps used a brass plate, or maybe copper

Ahh, this is helpful to know, thanks! Do you think that adhesive copper shielding run in the cavity would have the same impact as a copper plate?

[4Mal]

I voted no however I am of the mind that everything affects tone in some way. The shielding thing I think is a really minor component in the overall scheme of things.

I run Vintage Vibe P & J pickups that are themselves foil shielded. They sound great and are very quiet. ..not a combination I've experienced with any other 'low noise' design.

The tele pickup has a base plate. Some guys like copper, some alu, some steel. I like the edge of steel for the classis country twang. Blues guys dig copper or aluminum as they really wanted a P90 back there but for some reason bought a Tele.

[line6man]

As long as you don't wrap copper tape around the pickup coil, it shouldn't affect the tone.

[Arvin]

Originally Posted by line6man

As long as you don't wrap copper tape around the pickup coil, it shouldn't affect the tone.

+1

My observation has been that cavity shielding has a negligible effect on tone, but copper tape surrounding a pickup coil can indeed add some capacitance. I had a set of strat pickups a while back that were copper-wrapped, and after removing the copper from the neck and middle pickups, the tone opened up noticeably. I left the shielding on the bridge pickup, though, because it sounded a little better tamed down.

[Muckaluck]

Originally Posted by line6man

As long as you don't wrap copper tape around the pickup coil, it shouldn't affect the tone.

Originally Posted by pseudocat

+1

My observation has been that cavity shielding has a negligible effect on tone, but copper tape surrounding a pickup coil can indeed add some capacitance. I had a set of strat pickups a while back that were copper-wrapped, and after removing the copper from the neck and middle pickups, the tone opened up noticeably. I left the shielding on the bridge pickup, though, because it sounded a little better tamed down.

The coil is the little metal pole protruding from the pickup, right? Or is it the whole pickup?

[line6man]

Originally Posted by pseudocat

+1

My observation has been that cavity shielding has a negligible effect on tone, but copper tape surrounding a pickup coil can indeed add some capacitance. I had a set of strat pickups a while back that were copper-wrapped, and after removing the copper from the neck and middle pickups, the tone opened up noticeably. I left the shielding on the bridge pickup, though, because it sounded a little better tamed down.

Add some capacitance?
A quarter inch or so of air as a dielectric between one plate and another, insulated plate does not increase the capacitance much in an application like this.

The tonal effects of shielding a pickup coil are related to eddy currents, not capacitance.

[PhiDeck]

Originally Posted by Muckaluck

The coil is the little metal pole protruding from the pickup, right? Or is it the whole pickup?

Neither. Those are the magnetic polepieces. The coil, which you can't see, is very thin copper wire, wrapped around the polepieces' frame. The coil is an inductor, which converts perturbations in the polepieces' magnetic fields into an electrical signal. Those perturbations are caused by the motion of the strings.

[Arvin]

Originally Posted by line6man

Add some capacitance?
A quarter inch or so of air as a dielectric between one plate and another, insulated plate does not increase the capacitance much in an application like this.

The tonal effects of shielding a pickup coil are related to eddy currents, not capacitance.

Interesting. I had always assumed it was a capacitance effect, because it sounded like a tone control rolled back a bit. I guess I need to go study up on eddy currents...

[Clark Dark]

I thought the shielding was like a faraday cage. I always wonder why the shielding under the pup was so important because there's no shielding over the pup. Isn't the shielding protecting against RFI ? or 60 Hz hum ? .......or what ?

Is that the reason for factory fenders being equipped with those bells over the pup's ?

[line6man]

Originally Posted by Clark Dark

I thought the shielding was like a faraday cage. I always wonder why the shielding under the pup was so important because there's no shielding over the pup. Isn't the shielding protecting against RFI ? or 60 Hz hum ? .......or what ?

How exactly would you shield over the top of the pickup?
I suppose things like Rickenbacker horseshoe pickups, and Js/Ps with chrome covers do a minimal job of shielding, but it's really not effective or practical.

[mongo2]

Originally Posted by Clark Dark

I thought the shielding was like a faraday cage. I always wonder why the shielding under the pup was so important because there's no shielding over the pup. Isn't the shielding protecting against RFI ? or 60 Hz hum ? .......or what ?

When I want a silent bass I use something like Bartolinis that are completely shielded and any necessary cavity shielding.

[darkstorm]

No doesnt affect tone except to the effect that theres less hum and less chance of hearing some radio station in the background. Lol.

[C.Linton]

Originally Posted by Clark Dark

I thought the shielding was like a faraday cage. I always wonder why the shielding under the pup was so important because there's no shielding over the pup. Isn't the shielding protecting against RFI ? or 60 Hz hum ? .......or what ?

Is that the reason for factory fenders being equipped with those bells over the pup's ?

Originally yes. You can still see on some early 50's p-basses the ground wire that came up from the pickup leading to the screwhole where the pickup cover attached. It wasn't long, however, before they figured out it didn't really work all that well, so they stopped grounding the covers. At at that point the covers were mostly aesthetics and a place to rest your palm when playing with the thumb.

[mongo2]

Originally Posted by C.Linton

Originally yes. You can still see on some early 50's p-basses the ground wire that came up from the pickup leading to the screwhole where the pickup cover attached. It wasn't long, however, before they figured out it didn't really work all that well, so they stopped grounding the covers. At at that point the covers were mostly aesthetics and a place to rest your palm when playing with the thumb.

Interestingly enough, the pickup cover on the P bass was actually grounded until they stopped using the full sized under the pickguard shield. Intentional or not, the screws for the pickup cover would contact the shield as they passed through it. Since the shield was grounded to the pots and jack, the cover was then also gounded. I can see how that type of connection could be somewhat dicey and subject to failure but I've metered several over the years that were grounded.