guitar shielding (kind of OT)

[sfr]

The plastic boxes thread reminded me of a question I meant to ask. . .

I'm doing some wiring work on my old strat copy (it hasn't worked for years, I figure it's time to fix that) and while I had it apart, I figured I'd put on a new pickguard and shield it.  (although I'm fairly confident, I figured I'd use the shielding the instructions here and make sure I got everything right- can't ever have too much help!) Down at the music shop buying some strings, I asked if the had any shielding tape, thinking to save myself a trip to the hardware store.

Well, the guy at this guitar shop has this horrible tendency to talk down to people, and my conversation was just frustrating on many levels.  I just wanted to buy my stuff and go, but that's beside the point . . .

But anyway, he was adamant that shielding the guitar would do absolutely nothing for it - I get the feeling from the conversation that he didn't make a continuous ground plane  - (am I using the right wording here?) it sounds like he just slapped metal tape in there w/o making sure the pieces conducted across or where attached to ground, which I'd imagine wouldn't really help at all?   But again, I'm uncertain as to exactly what he meant when he said sheilding (although it was different from what I meant) , I wasn't about to push the conversation because I'm not a huge fan of conflict and was in a hurry.

But I do wonder, is he correct?  Will the effort of shielding (if done properly) yield no appreciable returns?  

Also, he made a big point of explaining that turning away from the amp will help noise (thank you) and not standing near flourescent lights (which I know about - makes me wonder why my local club has them hanging so low by the stage . . .)  but also that I shouldn't have my amp plugged into the same circuit as anything else.  Now, I tend to avoid plugging my amp into circuits already busy with lots of other things, particularly appliances, because it sucks when your driving a stack and the fridge kicks in or something and you blow the breaker and have to crawl around in the basement, and in general I usually have it the only thing in the outlet it's using, but he seems to be convinced that I'm going to be getting significantly less hum if it's the only thing on that entire circuit - no lights or anything - apparently his house is wired much better than mine or he plays in the dark.    

So, is there any validity to that arguement?  It's kind of difficult because of the wiring of my house to check that out, and hum and noise isn't really a major issue in my setup at this point as it is, I don't know how much I'd notice the difference, especially given that I've already started repairing the flaky wiring in single coil guitar.

Sorry I sound so negative and down on the guy - I don't mean to come off as much of a jerk as I sound here.

[Mike Burgundy]

proper, ground-connected shielding WILL yield very significant results, especially with single coils. Even when not connected to ground it *can* be benificial.
Copper tape works very well for this. Make sure you solder the pieces together though.
It's the same as having a stompbox that's not shielded - actually it's worse. Single coils make for brilliant hum antennas.
The shielding creates a "Faraday's cage" around the pickups and wiring, inside which "no" external signals can exist.
Ofcourse, the pickups are still exposed towards the strings so the cage isn't perfect, but on the whole external interference is greatly reduced. Even shielding just the scratchplate will pull away a lot of interference.
My guess is he has humbuckers, and has not executed the shielding well. He obviously doesn't know what he's talking about, has misunderstood the question or was talking about something completely different altogether

That said: stuff like fridges will produce a big jolt on the powerline (mainly when switching OFF, not on) that may be heard through an amp. High powered poorly built (or even plain old) lighting or motors (fans!) can produce buzz, superimposed on the AC grid. A not-so-well isolated amp might reproduce that buzz.
Fluorescent lights (and TV's, monitors, computers...) produce a heck of a lot of EM-interference that will be heard through your pickups. Standing very close to your amp will have the same result, although it may sound different (fluorescent lights buzz at twice the AC frequency, power supplies usually at the fundamental).
Fluorescent lighting may produce such a massive amount of interference, even a well-shielded guitar may pick it up.
Turning away from the amp, having no fluorescent lighting present, no heavy equipment on the same circuit are all good advice. They carry no evidence on the merits or drawbacks of shielding by themselves though.

[Ge_Whiz]

Rest assured that your guitar-shop-guy is the jerk. Shielding your guitar the Guitarnuts (TM) way will improve things enormously. I recently rewired my guitar with a most complicated harness and it's MUCH better now than before (though not perfect if I stand right over the amp). Make sure you follow the instructions carefully, solder all the sections together, ground everything at one point, and if you use any screened cable within the guitar, ground the braid at only ONE end. Then you'll be able to take your axe to the shop and challenge the guy in front of everyone (nah, don't bother - find a better shop).

[Ed G.]

Shielding your guitar can also increase capacitance and I found in my strat it deadened the tone somewhat, similar to turning the tone control down a few numbers.

[Chris R]

They also make some shielding paint (no soldering tape involved).  Although, i'm guessing its alot more expensive.  

check out http://www.stewmac.com/ for supplies.

I used aluminum tape on mine.. it was kinda a pain to solder all the tape pieces together.  (Use big pieces when possible)  

Switch your DMM over to continunity beep.. to check if all the grounds are connected.

C

[Fret Wire]

Go to Stewart McDonalds and get their copper shielding tape. It has conductive adhesive so there is no solder tacking the overlapped joints. The pickups are the highest source of hum on your guitar, but sometimes, shielding them will knock the high end off your tone. Not always though. If it does, remove it from the pickups, and back off a 1/4" from the pickup cutouts on the pickguard.  Do your entire pickguard, not just the control end. That also kills the static hum from playing. Tape right over the holes and cut out with an exacto, that way your pots and switches will make ground. You also want to run little tabs of tape from the body cavity to the top of the body where the pickguard screw holes are.  That connects it. It should be a continuous ground with no resistance anywhere you measure. The hum reduction comes from not only the tape, but the ground wiring work also. That is a good link to reference.

Does it work? Absolutely! On single coils, you can hear some harmonics and subtle nuances that the hum previously drowned out. I want to try it on my first pedal project.

[BILLYL]

Shielding will greatly improve the sound.  One thing - the copper tape you get from Stew Mac is pretty expensive.  I get my copper tape from a store that sells stain glass supplies.  Check your local phone book for a supplier - cheaper way to go.

BILLYL

[Fret Wire]

Does that tape have conductive adhesive? If not, it's pain in the ass solder time. Stew-Mac's is slightly expensive, but there are no specialty stores where I live. I'm sure a decent electrical supply store has it cheaper, but versus solder tacking the overlaps, it's worth the price.

http://www.stewmac.com/shop/Electronics,_pickups/Supplies:_Shielding/Conductive_Copper_Tape.html

[JohnM]

I did the guitarnuts thing to my strat w/the copper tape (from StewMac), all soldered, etc.

I don't know if it really helped.  Sometimes I wish I didn't do it, and that it was a waste of time.

I suspect that my strat (1981-ish) has shielding paint in the cavity already, and so was reasonably quiet already.  (?)  I think I was being too picky about noise.  (?)

Just something to think about...  

BTW - one cool mod I did at that time was to put one tone control on the bridge pickup.  I find myself using that a lot.  -John

[aron]

This is an interesting thread to me.

I have one Pacific which is shielded with paint and copper. I still have problems with buzz (not hum). I do have Bill Lawrence 280s pickups in it in addition to a humbucker in the bridge. I have no idea why it still makes noise.

I have another guitar which is a humbucker in the neck, single coil in middle and humbucker in the bridge. This guitar is largely silent with no appreciable shielding.

I have heard John Suhr model strats - single coils too - be almost totally silent onstage when run through distortion pedals and a loud amp.

I have no idea why they react so differently with regard to noise.

[Ansil]

theres a funny thing you can do if you have the time and want a quick easy way to shield a guitar..

i found sheilding paint dont' do dick.. around my place.. usually i don't have hum. but when i do you might as well go to bed cause it aint getting better.

take some aluminum foil and blend it in a blender. with some water to keep it from going crazy..

conductive glue.. most hobby glues at the train store that sell generic big bottles of thick superglue type stuff is conductive.  

buy one bottle and mix up the appropriate amount of shreded aluminum to glue and apply to inside of yyouru guitar.. works on plastic pedals..  no need for glueing jigs or anything.

[Gringo]

Hey Ansil, could you explain this a little more?

How do you blend aluminum foil in a blender ? Furthermore, what is a blender?    :?

I already told you, but man, i really dig this kind of stuff you come up with

[Ansil]

no problem man.

a blender is a food type processor that chops and grates food or anything you can submerse safely in liquid..  ie plastic pop bottles minus the labels.
aluminum foil..  etc.

you basically have to do a little homework..  you need a conductive glue.

which means the glue has to conduct electricity.  you can find out either by testing this or by checking the internet.. the hobby shop i used to go just so happened to have looked into this for soemone else. so i just happened to luck up.

take a sheet of aluminum foil and cut it into some squares.  about 2 by 2 or smaller you can even ball it up in little balls but this is a little redundant. and is harder to predict the output.  

blend puree shred whatever you wish to the aluminum foil in the blender.  i always add water so it wil kind of be like a solution instead of a dry mix.. when it is dry the stuff on top doesn't drop down to be cutt up.

so anyway you should have some little shards of foil floatin in water now..

take a strainer.. the kind for getting tea grounds out of liquid. like cheesecloth suspended by a container.. or use some old pantyhose if you have access to some..

personally i know a lot of women so i always have some pantyhose available..  (corner of the bedpost....  heheheheh) anyway i digress.

once it is strained go ahead and let it dry.  then mix in enough glue and foil in a bowl.. stir it ukp with a good stick and when it starts getting thick start spackleing.  like you would drywall or whatever.. once it dries you can put a screw..(if you are doing a guitar.) through it and attach a ground point to this.

more fun things to do is you can shred those plastic pop bottles and add glue and drop it on your fx pedals tops to keep a nice clear hard coat on top of it. you can also melt this on top of the effect if you so desire.  

keep smiling..  

[Kilby]

Well to me if shielding was good enough for Leo Fender it's good enough for me. Fender added enough shielding on the Jaguar (copper in the body routing, and serrated shields around the pickups).

Another suggestion, rather than the copper tape, get the copper craft foil (it comes in various thicknesses), and cut to size, then you can solder (or should I say braze) them together.

Rob...

[Ansil]

carvin had a cool deal on their guitar wiring kits...
www.carvin.com

[Doug B.]

This was a tip a while back on this forum (sorry i can't remember who sumbitted it -- but THANKS!):

You can use "snail foil" that you can get at your local garden-supply center (some department stores even have garden centers).  Snail foil is a thin, adhesive-backed, copper foil that -- i take it -- repells snails!  I guess you typically wrap a little piece in a ring around the stem of the plant you want to protect.  

Well, it works great for shielding pickups too!  I just used it on one of my Strats.  I cut a length of it into strips just the width of the coil, soldered a short thin piece of solid wire across one end of the strip, and applied it -- in one layer -- around the pickup coil.  Then i CAREFULLY soldered the wire to the pickup ground terminal.  Took about 15 minutes to do all three pickups.  

Although i didn't do a shielding of the cavity or pickguard, the stuff i got seemed to be conductive across the adhesive, so i'm guessing it can be overlapped without having to solder one piece to the next.  (It's probably a bit more than an inch wide.)  Nevertheless, it was EASY to solder a wire to!  

The roll of snail foil i bought cost about $7.  I don't remember right now how much foil comes on the roll, but doing the one Strat hardly made a dent in it.  

- Doug B.

[javacody]

Here is a product I use, because I am too lazy to cut my own shields:

http://www.monteallums.com/Product_links.html

[Fret Wire]

Those pre-cut shields are nice. The guy goes overboard on the mojo, though. Sometimes, it sounds noticeably better, because subtle harmonics and some of the pickups character are no longer being drowned out by hum. And again, some respond well to the pickups being shielded, and some lose high end. Perfect for the guitar that has too much high-end bite. Guitars that are already shielded don't yield a huge improvement. Works best when your whole chain is quiet: good cord and quiet amp. Many of the newer Strats, LP's, and their clones don't use standard 250k and 500k pots or tone caps. Cheap switches too. Replacing those at the same time you shield can make a big difference. Too many people go right to pickup replacement before they check the full potential of the stock setup first.

[Doug B.]

Ok, i have the package in front of me.  It's called "Snail & Slug Copper Barrier Tape" , and it's manufactured by a company called Safer.  It measures 1 1/4" wide by 15' (yup foot) in length.  It cost me $7.49 (before sales tax), and i purchased it at a local garden center / grocery store.  

Happy hunting!  

- Doug B.

[Dai H.]

This is an interesting thread to me.

I have heard John Suhr model strats - single coils too - be almost totally silent onstage when run through distortion pedals and a loud amp.

I have no idea why they react so differently with regard to noise.

Those may be hum-cancelling and not regular single-coils. His own special version of a DiMarzio hum-cancelling model IIRC.

IME, some hum-cancelling without extra shielding in body cavities seem quieter than regular humbuckers with. Or maybe the output of the pickup affects this as well. Some people say adding the extra shielding reduces highs, and I suppose if you went as far as putting the tape right around the coils, that would seem more likely. I've wondered what sort of improvement could be made with a thought out grounding scheme (separating the shield and signal grounds, or working out in detail how they are configured), pseudo-balanced cable out of the gtr. and maybe a RF suppression 10nF to ground in the mix, but so far, I don't think I've had any really bad problems with buzzing, RF interference, etc.