Eliminating electrical noise in your guitar

For many of us who love the sound of single coil pickups (eg. classic Strat or Tele) we are familiar with 60 Hz hum, radio stations, and cell phone signals coming through our amp.  This is electrical interference that our single coils are especially susceptible to, and yet we refuse to give up single coils, we just love the tone too much!  Humbuckers are a great way to fight this 60 Hz hum, if you have ever played a guitar with a humbucker and a true single coil you can easily hear the difference, but a lot of players complain that too much tone is lost when the hum is "bucked."  The truth is, you can stick with your old single coils as long as you follow a few DIY procedures that are guaranteed to reduce the noise to an absolute minimum.  Even if you have humbucking pickups these steps will help reduce the overall noise of your rig.

Step 1.  Shielding Paint

With the pickguard and electronics removed from the guitar, you can paint shielding paint from Stew-Mac on the inside of the control cavity and the pickup routs.  Two or three coats (allowing it to dry overnight between coats) should provide enough coverage.  All grounding material must come in contact somehow with the back of the potentiometer (ground).  Connect a ground wire from the paint to the back of a potentiometer or paint up to a screw hole so the paint comes in contact with the copper tape on the back of the pickguard (see step 2).

Step 2.  Copper Tape

This tape (also from Stew-Mac) is great for sticking to the back of pickguards and totally blocking out any interference.  The tape is grounded by coming in contact with the switch and potentiometer casings.

Step. 3  Leads

Keeping all electrical connections to an absolute minimum length will reduce the chances of interference.

Also, twisting the positive and negative leads from your pickups (as seen on this Jazz Bass pickup) will help cancel interference.  It is debatable whether this makes a noticeable difference in passive equipment, but it won't hurt, some like it for aesthetics and wire manageability.

Step 4.  Final details

Having a good quality, shielded instrument cable free of cracks and keeping it as short as possible will help tremendously in avoiding interference.

further reading:

Eliminating Troublesome Hum & Buzz Created By Electric Guitars by Bruce Bartlett 

Canceling Tele hum on the cheap

For more than 50 years, the Fender Telecaster has been manufactured pretty much the same way. It's trademark sound is one of raw, gutsy tone with sharp attack and great clarity. Because of it's simplicity and honesty, it is perhaps the best way to showcase a pair of single coil pickups. One of the drawbacks of true single coils is their hum which guitar makers have been trying to fix for decades. Since the Telecaster's design was perfected rather early on in electric guitar history (1950) it is one of the only dual pickup guitars that did not have hum-canceling capabilities, and it still doesn't today. Most of the time the two pickups are made reverse-wound/reverse-polarity so that when they are used in combination (the middle position of your pickup selector) they will cancel the hum. The telecaster design has been pretty much left alone because so many players love the trademark sound and especially the sound you get when the neck and bridge pickup are played together. For a lot of players that is more important than "bucking" the hum, but for you it might be more important to have a quiet setting on the guitar. Here I will show you how to cheaply and easily buck the hum on a standard Telecaster. 

As we just discussed, most Tele pickups are wound the same direction and charged with the same polarity facing up, making them non-humbucking, so all you need to do is switch the leads and reverse the polarity on one pickup. You can test the polarity by holding a compass up to the top of the pickup as shown below. Opposites attract, so this pickup is charged SOUTH UP (fig. 1).

fig. 1

Reversing the leads on a pickup is a simple operation with a soldering iron, but charging the magnets will be a little more tricky.  Especially since most vintage, and vintage-reissue Telecasters have a copper-plated steel baseplate on the bridge and a chrome cover on the neck pickup, which is soldered to the ground of the guitar.  

Modern American Standard bridge pickups, like the one shown below, do not have a baseplate, and are changed NORTH UP (fig. 2), so here I will remove the pickup and charge it SOUTH UP.

fig. 2

This can be done with a pair of 1" rare earth magnets from Steward-Macdonald ($8.57 each).  These are extremely strong magnets that will successfully charge Alnico polepieces like in my pickups here.  They will also successfully erase hard drives like in you iPhone or MacBook, so keep them away from all computerized equipment.  You can see the magnetic field you are dealing with by holding it to a compass .  It is attracting the NORTH needle, so this is the SOUTH pole of the magnet (fig. 3).

fig. 3

Charge the pickup polepieces by moving them back and fourth between the rare earth magnets.  The magnets will change magnetic fields of weaker magnets to what they are most attracted to, so a SOUTH pole with charge pickup polepieces to be NORTH.  Rare earth magnets will hold themselves to the jaws of a vice.  Label the side that will charge magnets to be North as I have done below (fig. 4).

fig. 4

Adjust the jaws so that the magnets are as close as possible to the polepieces but still allow the pickup to pass freely.  Move the pickup through the jaws of the vice a few times and it is fully charged.  Reinstall the pickup with the leads reversed.  Positive leads are usually white or yellow and in this case would be soldered to the ground (the back of the potentiometer), negative leads are usually black, blue or green and in this case would be soldered to your switch.  

If this pickup had a metal baseplate (fig.5) or a cover it would be a little more difficult to charge the magnets but sill possible.  It would require disconnecting the negative (ground) lead from the baseplate or cover and running a separate ground wire from the baseplate to the back of the potentiometer.  Then, special care must be taken to break the hold of the potting wax and remove the baseplate or cover without damaging the coil.  Then you can charge the magnets.  

fig. 5

Now you have a hum-canceling mode on your Tele without effecting the tone of the bridge or the neck pickup!

The hum-canceling Telecaster bridge pickup

single coil sound with the ability to "buck" hum!

Anyone who plays a Tele knows that they are vulnerable to interference and thus create a lot of hum through the amp.  Single coils naturally create a 60 cycle hum and there is no way around that.  Some companies offer solutions like samamium cobalt noiseless pickups, or stacked humbuckers, but usually at the cost of tone.  Some guitars with two pickups can be wired out of phase to cancel hum between the two pickups, but on a Telecaster even the middle position on the pickup selector offers no hum-canceling effect.  That's because both coils are wound counter-clockwise and the poles are charged North-up, partly because hum-canceling technology was non-existent in the 50's and partly because that middle position tone has become such a trademark of the Tele tone.

One of the best ways to combat hum and still keep the single coil tone is to have a split-single coil wired out of phase, like a P-Bass pickup.  What I have created here is essentially a P-Bass pickup that looks and sounds like a Telecaster pickup.  One coil is wound counter-clockwise and is charged North up and the other is wound clockwise and is charged South up.  They are then wired out of phase to cancel hum.  All of the normal Tele characteristics like a copper-plated steel baseplate, cloth-covered leads, and vintage-style flatwork are included.  I don't want to give the impression that I was the first one to do this, but this is not something you can just walk into Guitar Center and buy.  They are wound to 7k and are available for Teles for $125 each.  Contact me here to order yours.