Best way to shield pickups.

Discussion in 'Just Pickups' started by Digiplay, Feb 21, 2020.

  1. Digiplay

    Digiplay Tele-Meister

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    I've read that guitars with single coil pu's can benefit from lining the body cavity's with foil.


    Is copper or aluminum tape better, or will aluminum or copper foil work just as well?



    If copper/aluminum tape is the preferred way, what's the best type/size to buy, and where can you buy it?
     
  2. dougstrum

    dougstrum Tele-Afflicted

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    I use aluminum duct tape. You can get a roll at the local building supply or hardware store.
     
  3. Musekatcher

    Musekatcher Friend of Leo's

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    I used copper, couldn't tell a difference. I've since learned, that overlapping tape is not a good shield - it "leaks" higher frequencies thru the overlap. Also, the adhesive prevents layer-to-layer continuity, so you have several "shields" that aren't grounded to each other unless you do some kind of folding or soldiering. Conductive paint, or a single continuous layer of metal should be more effective.
     
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  4. eallen

    eallen Tele-Afflicted Silver Supporter

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    Copper tape will do the trick an realize you are just reducing interference, not making it some airtight seal. And actually overlapping does not leak more than a but joint if the tape is passing continuity thru the adhesive. I always check for continuity between cavities and grounds.

    Also realize shielding does not render single coils noise free should the right interferance and bad grounded electrical wiring come along. It does reduce it from every light bulb you come across though

    Eric
     
  5. 3-Chord-Genius

    3-Chord-Genius Poster Extraordinaire

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    I've seen friends shield the pickup cavities of their guitar, but I've never found single coil noise enough of a problem to do this. Especially today; stage lighting systems and general overall wiring in venues doesn't seem to cause as much of an issue as it used to back in the day. I think the reason I've never done the shielding is that it seems like a pain in the rump, with a lot of weak areas for interference to get through anyway.
     
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  6. Matthias

    Matthias Friend of Leo's Gold Supporter

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    Copper or aluminium work. Aluminium is paramagnetic so affects the magnetic field slightly. Aluminium pickguard shields slightly attenuate some of the “ice pick” frequencies in single coils. Aluminium tape is much thinner but there may be some effect. Audible? Debatable... You can get some capacitance between the wire and any shielding in theory but I’ve never noticed my tone suffer.

    Overlapping is fine as long as you buy tape with conductive adhesive. Check continuity at points all over the cavities with a multimeter. Remember you need to ground all shielding too. I attach a wire to a pot and solder a screw lug to the other end, then screw that onto the tape. You’ll always have hum with single coils but you can much reduce it through shielding.

    You can see how I do it here: https://www.tdpri.com/threads/jag-build.930958/page-2#post-9158375
     
  7. Wound_Up

    Wound_Up TDPRI Member

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    I did mine with aluminum foil ducting tape and didn't check continuity...because I forgot to until it was already back together.

    It works so well that I initially thought I had pulled a wire loose when I had it apart so it wasn't producing sound anymore.


    Nope. Everything was intact. Its just that much quieter, now. I generally enjoy playing it that much more because of it. That hum used to bug me sooooo bad. So much that I hated even using the thing. Being an inexpensive import, I suppose it probably hummed a bit more than a Fender or even a Squier. Somehow, I even managed to solder the ground wire to the tape.

    The only time I get noticeable hum now is when I crank up the volume & OD(gain?) on this little practice amp.
     
    Last edited: Feb 21, 2020
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  8. Digiplay

    Digiplay Tele-Meister

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    Explain the part about checking continuity, and is it necessary?
     
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  9. LuckyNat

    LuckyNat NEW MEMBER!

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    I guess it means checking conductivity between different strips of tape in the same area and also between the tape and earth. If electricity can't flow from every part of the tape to the earth on the output socket, it won't be shielding at that point.
     
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  10. Digiplay

    Digiplay Tele-Meister

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    Is there a way to buy a larger solid piece, and then form it to fit the cavity?
     
  11. Digiplay

    Digiplay Tele-Meister

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    Matt,

    Where do I buy the copper sheet, and the copper tape with conductive adhesive?

    Jerry
     
  12. Matthias

    Matthias Friend of Leo's Gold Supporter

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    I find it all on eBay and Amazon. It doesn’t normally take too long to find. I’ve even used anti-slug tape in the past! Just check the descriptions for conductive adhesive. For the sheet, I read the reviews for how easy it is cut... I use some medical shear-style scissors for that sort of thing.
     
  13. schmee

    schmee Poster Extraordinaire Silver Supporter

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    I seem to post this almost weekly:
    Here's what I do:

    Shielding and for static pickguards:

    I have had static issues with Teles a lot. Not sure why that is. Ensure your bridge is grounded.

    Shield the pickup cavities and the control cavity with metal tape. Aluminum from the hardware store is fine. Just do the easy shielding, it doesn't need to be 100% , just a wide rectangular strip under the pickup and control is fine. Carry the shield out of the cavity and over the top edge a bit... maybe 1/8". Just so the pickguard tape contacts this.

    Make sure all the pots are grounded together, take that ground to a small solder tab in or near the bridge pickup cavity. Solder the bridge ground wire to this tab also. This little tab is screwed thru the Aluminum tape into the body for contact. (Fender uses this tab... on their better guitars anyway.) You could just use a wire around a screw.
    many USA Fenders use this tab already:

    Put the Aluminum tape on the back of the pickguard if there is none. (doesn't need 100%) The goal is to have this tape contact the cavity tape (where it bends over the top of the cavity edge) when the pickguard is screwed down and thus grounding thru the little solder tab.

    Here's what I have done additionally for hum :
    use a shielded wire from the input jack to the pot. (this is for hum elimination if you need it) Ground only one end of the shielded wire.
     
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  14. jvin248

    jvin248 Poster Extraordinaire

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    .

    Here's the list. Don't think about it too hard. just get the stuff and install:

    -Shielded cable to the jack. Those two wires Fender uses collect noise, and twisting doesn't help. Otherwise we'd use twisted pair from the guitar to the amp.
    -Aluminum flashing tape (Nashua brand), overlap the tape and check continuity piece to piece as you put it down. Make sure some is over the top lip to contact the pickguard.
    Copper is less useful for shielding than Aluminum, copper 'looks better' so people use it. I'll leave the google research proof for you to find. If you take your cell phone apart it uses a lot of aluminum to protect itself.
    -Covered pickups protect against noise.

    Put the $7 multi-meter you got at harbor freight on "ohms" and first touch the probes to each other to ensure they are working, then touch two points of things you want to see if they are continuous.

    .
     
    Last edited: Feb 21, 2020
  15. hopdybob

    hopdybob Tele-Afflicted

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    copper and alu together in the control cav, copper surrounding the pickups.

    how i come to this?
    read these 2 Bill Lawrence articles that can be found here (with much more good reading stuff)
    http://billlawrence.com/Pages/All_About_Tone.htm/Pickupology.htm

    1 http://billlawrence.com/Pages/All_About_Tone.htm/TeleLovers.htm
    2 http://billlawrence.com/Pages/Pickupology/External Interference.htm

    a quote:
    Aluminum has some strange properties, and it's the only commercially available metal I know of that can eliminate the buzz caused by light dimmers. An inch thick copper or brass shield cannot reduce the buzz caused by light dimmers but .003 thick aluminum foil can! This is known some thirty years and the reason why Belden introduced double shielded cable ( Copper braid plus aluminum foil). There is one problem for guitar cords -- the double shielding makes the cable too stiff . It helps quite a bit when you shield your guitar with copper and aluminum foil.
     
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  16. Rob DiStefano

    Rob DiStefano Doctor of Teleocity Vendor Member

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    my personal case for the the absolute best way to shield pickups, particularly single coil pickups, is to not (not "shield" those pickups, that is) in most, but not all, instances.

    ... loving single coil pickup tone and perhaps learning to live with some noise ...

    the signal produced by the vibrating strings through a magnetic field is induced into the top of a transducer's (pickup's) coil and runs through its lead wires most likely to some circuit that contains a few potentiometers of varying resistance (that can throttle the signal to ground, and in doing so will also shunt treble frequencies to ground as well), a capacitor (maybe two) that shunts treble to ground, a signal director (pickup switch) and then heads out to a coupling device (jack) that will send what's left of that changed signal outboard to other "stuff" (maybe modulation = pedals) that may or may not further contort the tone of that signal, and will typically end in some form of signal amplification so that sound can be heard by human ears ... hopefully good sounds that one can call good music that makes for happy human ears.

    so where does that darned humbuzz noise come from? it mostly lives in that area we like the most about a signal, the peaks and valleys, which is also where the treble lives. dual coil humbucking pickups cancel out most if not all of the humbuzz, that's a fact, but it's also a fact that the treble frequencies are also greatly affected. we all know than, right? we all figured out back in the 70's that pulling off those gibson PAF ground shield metal covers added some kick-ass treble at higher volumes. but remove or mitigate the humbuzz of a single coil pickup, and so also may change the treble, and so also may change the tone, drastically sometimes.

    there's no free lunch with passive hi-z pickups. if "real deal vintage single coil tone" is a desired goal, in all its "vintage" gory (er, glory), there will be humbuzz happening to some degree. it is what it is and no one has stumbled on a way to separate the buzz from the treble 100%. some, like the Ilitch lo-z dummy coil system, are remarkably close, perhaps the best it will ever be for a true single coil pickup - but it's not a system for all guitars or everyone, requires an installation left to a pro, and is expensive, unfortunately. still, i'm very impressed with the Ilitich lo-z system.

    since it's the top of a transducer coil that acts most like a signal inducing antenna (thank you bill lawrence, i still miss our very interesting conversations, you are missed by many), so it's also a humbuzz antenna; the sides and back of a transducer not so much. once past the coil, the signal path leads are fresh meat for humbuzz attack. in a typical tele, the control cavity is where the pickup leads end up and that big grounded control metal plate acts as an RF shield. however, the more iron and "stuff" in the circuit, the more one can expect signal treble loss due to capacitance of the circuit. this is also true of adding forms of grounded shielding to any part of the engines (pickups), their path (leads), and what they feed (the onboard circuit). shielding the induced signal with foil (copper or aluminum), or carbon paint, will compromise treble to some degree. well how much will be lost? one needs to do it and listen to the results, no way around that.

    so, if perhaps the biggest culprit of sucking in RF noise into a pickup produced signal is the top of the coil, perhaps making the top of that coil have as little footprint as possible can help? hmmm. compare the average noise induced levels between a gibson p-90 pickup and a fender strat pickup. fat and wide versus tall and narrow. interesting?

    yes, the more gain one adds to the signal - pedals, amps, etc - the wilder the noise levels become, and for some guitarists and music, the humbuzz is just too over the top and this may mean that using true single coil pickups makes no sense, time to go with noiseless engines and be done with fighting the buzzy beast - that argument makes absolute complete logical sense to me. pickups are just tools for making good music. choose the right tools.

    hey, it's all good, i find no fault in doing lots of shielding or even going dual coil noiseless as long as the end product, the good music produced, is satisfied.

    BUT, something needs to be said about straight up single coil tone, unfettered by "shielding", who's signal is fed to a good amplification source, where some kinda aural magic occurs that's just so wonderful to the ears.

    twang on, brethren of the tele :)
     
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  17. hopdybob

    hopdybob Tele-Afflicted

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    well written Rob, and like i wrote somewhere else, for a lot off us the reference sounds from our guitar hero's were from a time that humbuzz was part of the sound and todays users would not use products and materials they used then, like the curled cables.

    but your antenna explanation. why not then use some copperfoil ore something else above the winding ore on top of the bobbin(maybe grounded) to shield it ?
    i think it never is sought out what the new electronic storms do it our guitar chains.
    when i sit nearby my peavey express 112 amp, and have the remote control for the hifi set and use that to chose another song, i here a sound using it pressing the remote button through the amp.
     
  18. tubelectron

    tubelectron Tele-Holic

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    For example, here is pair of Harley-Benton JM pickups :

    [​IMG]

    Due to their large size, they have a wide captation window which makes the JM pickups sound distinctive but increase their tendency to pick hum and RF interferences - like OEM Fender JM, P90, Mosrite pickups do.

    I shielded these pickups with auto-adhesive aluminium ribbon as follows :

    [​IMG]

    No more hum nor RF interferences. 100% efficiency.

    I must say also that JM Roswell Harley-Benton pickups are RWRP, unlike OEM Fender, AFAIK... ;)

    By my experience, aluminium is as good as copper for that kind of shielding, and much less costy : you can find it in DIY stores, at the supply department for thermal insulation for circa 10 Euros the 100 meters roll in 100mm wide... :cool:

    But it's me, OK ? :D

    -tbln
     
  19. Rob DiStefano

    Rob DiStefano Doctor of Teleocity Vendor Member

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    yes
    yes, ground shields will shield the signal from the humbuzz, and ground shields of any type or manner will also shunt treble to ground, changing tone to some minor or major degree. that's the bugaboo of ground shields that surround anything that harbors a signal. take the ground shield cover off a tele neck pickup and listen, as an example. there's no free lunch when it comes to any attempt to squash the single coil humbuzz, it will always be a compromise of sorts.
     
  20. hopdybob

    hopdybob Tele-Afflicted

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    thank you for explaining Rob.
    good history off all the great guitarist proved that fighting those compromises still can result in beautiful music
     
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