I should preface this by saying that this is really old information. I was doing this for players when I worked at a music store many years ago. Someone asked me a question about noise recently and I remembered doing this in the past so I thought I would share the technique.
Got a guitar with single coil pickups, like most all Fenders that picks up a lot of noise in certain venues? This trick can really help and it doesn’t constitute a permanent modification to the guitar. Since it is completely removable/reversible, it does not change the value of the guitar, even a vintage one. Incidentally, if you do not know how to do electrical soldering you might get somebody else to do it. A good job is important for longevity.
The way a magnetic pickup works is that the magnetic field from the magnet magnetizes the metal string just over it. When the string is played, its motion causes the magnetic field in the string to induce a voltage in the pickup coil which the amplifier turns into a larger signal that can eventually be fed to a speaker and be heard. This is called a variable reluctance pickup and most electric guitars use them. The bad news is they often pick up noise you don’t want along with the signal.
The first solution to this was the humbucking pickup. It uses two coils and one is opposite polarity from the other. The string only affects one and noise affects both. Since they are out of polarity, the noise common to both is canceled and you get only or mostly only get the sound of the string signal. The sound from a humbucking pickup is a little different from a single coil pickup. This may be good or bad depending on your preference.
If you like the sound of a single coil pickup noise can be a problem. There is a way to filter out a lot of that noise and you can do it with minimal or no influence on the sound of the guitar in the process.
You can shield the pickup from a lot of noise using what is called a Faraday Shield (1). A Faraday shield has little effect on guitar frequencies but a huge shielding effect on higher frequencies of noise-not so much on hum, like 60 HZ hum. The following text and pictures show how.
This is a picture of a Fender Telecaster bass pickup (this is an old one, the new ones don’t look like this but it is a good example of a single coil pickup) and a piece of copper foil glued to a piece of construction paper.
Why the paper? More about that in a minute. Measure the distance between the top and bottom cardboard or plastic parts of the pickup and measure the distance. In this case it is 7/16 of an inch. Cut a strip of copper foil and a piece of paper this wide and long enough to go around the pickup and overlap by a little then glue them together. Not every glue will work. You need something that will stick to copper and paper. Gorilla glue is what I used and it worked very well, probably contact cement would be ok too. You might find it easier to make the pieces a little oversized and trim to size with scissors after they are glued together. I put them between sheets of waxed paper in a book and weighted it down until it cured. (2)
Next, solder a wire to one end of the foil. This is one reason why copper is preferred, aluminum would work just as well but is very difficult to solder with conventional equipment.
Next, connect the non-soldered end of the strip to the pickup with a little piece of tape and wind around the pickup. Like this:
Wind the strip around until it overlaps and tape again like this and tape again.
Note that the paper is slightly longer than the foil, this is very important! If one end of the copper touches the other at the end, it forms a shorting ring and a partial Faraday cage. This is going to affect sound in a major way. Incidentally, the tape isn’t going to hold for long so at this point you want to wind some big thread or small string around the foil/paper to hold it. Resist the temptation to use masking tape or duct tape to secure the foil. Masking tape gets hard and duct tape turns to goo. The tiny strips of tape I used are Gaff tape which is ok for just securing things until you can do it right with string.
I haven’t put string this one yet but this is what it looks like from the other side:
So where does the shield wire go? The best place is to thread the wire back into the body of the guitar and solder to the ground outlet of the jack that connects the guitar to the amp. It helps to wrap that green wire around the white and black ones loosely on the way to the jack. It shields even more that way. If the brass plates under each pickup that the manufacturer (hopefully) put there are still there, you can connect there, it works ok. I suggest that you do not try to solder directly to the pickup. The wires are too fragile.
I guess it goes without saying that you have to do this to every single coil pickup and do only one at a time. You don’t want to mix them up. On certain guitars the magnetic polarity differs from one pickup to another.
(1). This is a reference for a Faraday Cage, which is a more complete shield than the one described here: Faraday cage - Wikipedia.
(2). Hobby Lobby sells copper foil in various packages, that is what I used.
Got a guitar with single coil pickups, like most all Fenders that picks up a lot of noise in certain venues? This trick can really help and it doesn’t constitute a permanent modification to the guitar. Since it is completely removable/reversible, it does not change the value of the guitar, even a vintage one. Incidentally, if you do not know how to do electrical soldering you might get somebody else to do it. A good job is important for longevity.
The way a magnetic pickup works is that the magnetic field from the magnet magnetizes the metal string just over it. When the string is played, its motion causes the magnetic field in the string to induce a voltage in the pickup coil which the amplifier turns into a larger signal that can eventually be fed to a speaker and be heard. This is called a variable reluctance pickup and most electric guitars use them. The bad news is they often pick up noise you don’t want along with the signal.
The first solution to this was the humbucking pickup. It uses two coils and one is opposite polarity from the other. The string only affects one and noise affects both. Since they are out of polarity, the noise common to both is canceled and you get only or mostly only get the sound of the string signal. The sound from a humbucking pickup is a little different from a single coil pickup. This may be good or bad depending on your preference.
If you like the sound of a single coil pickup noise can be a problem. There is a way to filter out a lot of that noise and you can do it with minimal or no influence on the sound of the guitar in the process.
You can shield the pickup from a lot of noise using what is called a Faraday Shield (1). A Faraday shield has little effect on guitar frequencies but a huge shielding effect on higher frequencies of noise-not so much on hum, like 60 HZ hum. The following text and pictures show how.
This is a picture of a Fender Telecaster bass pickup (this is an old one, the new ones don’t look like this but it is a good example of a single coil pickup) and a piece of copper foil glued to a piece of construction paper.
Why the paper? More about that in a minute. Measure the distance between the top and bottom cardboard or plastic parts of the pickup and measure the distance. In this case it is 7/16 of an inch. Cut a strip of copper foil and a piece of paper this wide and long enough to go around the pickup and overlap by a little then glue them together. Not every glue will work. You need something that will stick to copper and paper. Gorilla glue is what I used and it worked very well, probably contact cement would be ok too. You might find it easier to make the pieces a little oversized and trim to size with scissors after they are glued together. I put them between sheets of waxed paper in a book and weighted it down until it cured. (2)
Next, solder a wire to one end of the foil. This is one reason why copper is preferred, aluminum would work just as well but is very difficult to solder with conventional equipment.
Next, connect the non-soldered end of the strip to the pickup with a little piece of tape and wind around the pickup. Like this:
Wind the strip around until it overlaps and tape again like this and tape again.
Note that the paper is slightly longer than the foil, this is very important! If one end of the copper touches the other at the end, it forms a shorting ring and a partial Faraday cage. This is going to affect sound in a major way. Incidentally, the tape isn’t going to hold for long so at this point you want to wind some big thread or small string around the foil/paper to hold it. Resist the temptation to use masking tape or duct tape to secure the foil. Masking tape gets hard and duct tape turns to goo. The tiny strips of tape I used are Gaff tape which is ok for just securing things until you can do it right with string.
I haven’t put string this one yet but this is what it looks like from the other side:
So where does the shield wire go? The best place is to thread the wire back into the body of the guitar and solder to the ground outlet of the jack that connects the guitar to the amp. It helps to wrap that green wire around the white and black ones loosely on the way to the jack. It shields even more that way. If the brass plates under each pickup that the manufacturer (hopefully) put there are still there, you can connect there, it works ok. I suggest that you do not try to solder directly to the pickup. The wires are too fragile.
I guess it goes without saying that you have to do this to every single coil pickup and do only one at a time. You don’t want to mix them up. On certain guitars the magnetic polarity differs from one pickup to another.
(1). This is a reference for a Faraday Cage, which is a more complete shield than the one described here: Faraday cage - Wikipedia.
(2). Hobby Lobby sells copper foil in various packages, that is what I used.
