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Vintage threads from the first ten years

Re: Insulating pickups

8/29/2002 2:13 PM
Mark Hammer	Re: Insulating pickups First, let's clarify, you mean shield, not insulate. The wire itself is already insulated by its' coating (although the solder joints are not necessarily insulated). That's a small issue of semantics, though, and onyl mentioned so youcan articulate your needs a little more clearly in future questions. The wisdom of shielding depends on a few things. You may well "lose" something from various typs or degrees of shielding, but the question is "what?". You will note, for example, that many guitar players prefer lower value volume pots on their single coil equipped guitars because the lower value pots load down the pickups and bleed just enough high end to make them sound more vocal and less brittle (or so they say). So here is a case of something added to a pickup to remove some of what one doesn't like. It is easyto imagine there being instances where foil shielding not only reduces outside interference but improves the tone to the ears of the user. Not necessarily in all cases, but in some cases yes. I've done such shielding in the past and not noticed anything seriously lacking in tone, but then I wind my own pickups without attempting to get them to match some specific tonal standard (each one is an adventure) so I'm not in a position to judge what went missing. For optimal shielding, though, you'd probably like to have a ground connection securely afixed to whatever serves as your shield. Aluminum foil will work if you are content to have tape adhesive and friction maintain your electrical continuity for you. You might want to consider copper or brass shim, though, which you can solder to. If you attempt to use shim (which you can cut pretty precisely with regular scissors), keep in mind the following: 1) You can slice yourself and other objects pretty seriously with the edges on this stuff, so be VERY careful. It is probably a good idea to remove the burr from the edges of what you cut with sone folded over emery cloth while wearing good thick work gloves. 2) Solder your shield wire to the shim BEFORE you wrap it around the coil. The coil doesn't need that heat. 3) I find it a good idea to wrap a half dozen turns of teflon tape around the coil before putting anything on top of it, whether tape, shielding or whatnot. The teflon tape secures and conforms nicely to the coil without any heat or adhesive involved, This means you can undo anything you put over top without accidentally damaging the coil. The teflon takes up negligible room. A true 50 cent miracle. 4) If you do decide to go with shielding, wire up your pickups so that the two leads are "uncommited" with respect to ground (i.e., your connector cable needs to have two conductors and shield). This will allow youto maintain useful shielding should you decide to do any phase reversal of pickups. Finally, if your query pertains to humbuckers (as opposed to simple single-coil pikcups) there is absolutely no advantage of shielding over and above the standard metal pickup cover.

8/29/2002 2:13 PM

Mark Hammer

Re: Insulating pickups

First, let's clarify, you mean shield, not insulate. The wire itself is already insulated by its' coating (although the solder joints are not necessarily insulated). That's a small issue of semantics, though, and onyl mentioned so youcan articulate your needs a little more clearly in future questions.

The wisdom of shielding depends on a few things. You may well "lose" something from various typs or degrees of shielding, but the question is "what?".

You will note, for example, that many guitar players prefer lower value volume pots on their single coil equipped guitars because the lower value pots load down the pickups and bleed just enough high end to make them sound more vocal and less brittle (or so they say). So here is a case of something *added* to a pickup to remove some of what one doesn't like. It is easyto imagine there being instances where foil shielding not only reduces outside interference but improves the tone to the ears of the user. Not necessarily in all cases, but in some cases yes.

I've done such shielding in the past and not noticed anything seriously lacking in tone, but then I wind my own pickups without attempting to get them to match some specific tonal standard (each one is an adventure) so I'm not in a position to judge what went missing.

For optimal shielding, though, you'd probably like to have a ground connection securely afixed to whatever serves as your shield. Aluminum foil will work if you are content to have tape adhesive and friction maintain your electrical continuity for you. You might want to consider copper or brass shim, though, which you can solder to.

If you attempt to use shim (which you can cut pretty precisely with regular scissors), keep in mind the following:

1) You can slice yourself and other objects pretty seriously with the edges on this stuff, so be VERY careful. It is probably a good idea to remove the burr from the edges of what you cut with sone folded over emery cloth while wearing good thick work gloves.

2) Solder your shield wire to the shim BEFORE you wrap it around the coil. The coil doesn't need that heat.

3) I find it a good idea to wrap a half dozen turns of teflon tape around the coil before putting anything on top of it, whether tape, shielding or whatnot. The teflon tape secures and conforms nicely to the coil without any heat or adhesive involved, This means you can undo anything you put over top without accidentally damaging the coil. The teflon takes up negligible room. A true 50 cent miracle.

4) If you do decide to go with shielding, wire up your pickups so that the two leads are "uncommited" with respect to ground (i.e., your connector cable needs to have two conductors and shield). This will allow youto maintain useful shielding should you decide to do any phase reversal of pickups.

Finally, if your query pertains to humbuckers (as opposed to simple single-coil pikcups) there is absolutely no advantage of shielding over and above the standard metal pickup cover.

8/29/2002 8:00 PM
Jason Lollar	3M makes a copper tape with conductive adhesive, kind of pricy though. Availible from Mouser.com Very easy to solder a wire to, do so before wrapping the coil. Comes in different widths. Occasionally it gets requested which is the only case when I actually do it.

8/29/2002 8:02 PM
Jason Lollar	PS good to see Mark Hammer here, you missed some good conversation on the old forum.

8/30/2002 12:17 AM
Mark Hammer	Many thanks. Good to see you here too. The adhesive-backed copper tape is, I assume something similar to what Stew-Mac has sold for a while (visibly copper on one side, black and sticky on the other)? I've used that, but I still recommend putting something between the coil and anything adhesive. I gather this would be your advice as well, but I just wanted to make it clear to the too-adventurous out there.

8/30/2002 12:17 AM

Mark Hammer

Many thanks. Good to see you here too.

The adhesive-backed copper tape is, I assume something similar to what Stew-Mac has sold for a while (visibly copper on one side, black and sticky on the other)? I've used that, but I still recommend putting something between the coil and anything adhesive. I gather this would be your advice as well, but I just wanted to make it clear to the too-adventurous out there.

8/29/2002 9:37 PM
Tony@Mastertone	Dick That conductive copper tape manufactured by 3M is available from Complete Tape Solutions in Sydney at around $16 a roll... and they cut it to your specs. I can send you a small sample if you wish. Cheers Tone

8/30/2002 11:37 PM
Jason Lollar	Never applied directly to the coil!

8/31/2002 1:50 AM
Dick	Thanks for your help again, guys

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