How do humbuckers work?

Humbuckers are great for their warm, powerful tone, and best of all they "buck" the hum that single coils are usually are prone to.  60-cycle hum comes from electronics that surround us every day like florescent lights and power transformers, and it sure doesn't sound very good when it comes through an electric guitar amp.  That's why humbuckers were such a valuable invention when music was getting louder in the 1950's, but how do they work?

Humbuckers are basically two single coils arranged side-by-side (fig. 1), each with six magnetic poles or slugs (one for each string).  They are wired in a way that cancels the unwanted frequency and keeps as many of the good frequencies as possible.

fig. 1

Most modern Stratocaster guitars (fig. 2) have a humbucking option built in.  The middle pickup is reverse-wound/reverse-polarity to the neck and bridge, so that when they are used in combination they will cancel any hum.  This only works because the two coils are so far apart and the harmonic frequencies are so different, the only quality that is the same about them is the hum, so when the two coils are opposite, they cancel the hum. 

fig. 2 the middle and bridge or middle and neck pickups are hum-canceling together

 Humbuckers function a little differently than this. Since the coils are so close together (as close as they can possibly be without being on top of each other), they are sensing very similar sounds and they need to be out of phase to cancel the hum.  Humbuckers consist of two coils (both wound counter-clockwise) with opposite magnetic poles facing up, usually wired in series.  

Some people don't like how humbuckers aren't as clear or bright as single coils, but what a lot of people don't realize is that there are many different ways of building humbuckers to change the tone.  The original Seth Lover PAF humbucker (which is the baseline against which all other humbuckers are judged) consists of 5000 uniform winds per coil (not scatterwound), bar magnets mounted underneath, adjustable poles on one side, slugs on the other, topped off with a nickel-silver cover.  All of this makes for a pretty dark sounding pickup.  Which might sound great in certain guitars, but some guitars beg for bright, twangy tones.  You could use scatterwound coils (for a brighter, clearer sound) and solid Alnico polepieces much like a Strat pickup.  This is the formula I used for my Apex Humbuckers.

fig. 3 my Apex Humbucker

You could also have an underwound humbucker (say with 4000 winds per coil) for a brighter tone, and you could wire these coils in parallel (instead of in series) for pickup with a clear tone and absolutely no hum.  

So there are lots of different options when it comes to getting different tones out of humbuckers, they don't always have to be dark sounding.  Most modern humbuckers come with 4 conductor leads so you can split the coils, and you can look up a wiring diagram here to experiment a bit.  Knowing your color codes of your pickup wires will be very helpful too, here is a link to color codes of a number of popular humbucker manufacturers.

Strat Mod

Increase your tonal possibilities while leaving your Strat looking bone stock

a normal 250k tone control on the left and the modified push/pull pot on the right

One thing I have always loved about the Telecaster is the middle position of the pickup selector where you have the bright, aggressive tone of the bridge pickup combined with the warm, bassy sound of the neck pickup.  This is a sound that you don't normally hear coming from a Strat, but with a fairly cheap and simple mod you can achieve this and other tones, enhancing your tonal possibilities and without sacrificing any of the other tones or the looks of the guitar.

I can perform this mod to any Strat for about $50.  I can also make custom, pre-made pickguards with pickups, a switch, and volume and tone controls all wired up and ready to drop in your strat.  All you have to do is solder the output jack and connect it to the body with the included screws.  The cost of this depends on the options you include (pots, capacitors, pickups...) the sky is the limit.

Email me at schuylerdeanguitars@gmail.com to inquire about modifying your Strat.

If you are feeling particularly ambitious you can try this mod yourself.  Here is a link to a wiring diagram:

http://www.guitarelectronics.com/product/WDUSSS5L2101/WDU-SSS5L21-01.html

Just keep in mind that you will need a good soldering iron with a small tip, a 250k push/pull pot with a short rotary knob and a second capacitor.

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!

'62 Strat pickup repair

This morning I had in my shop a bridge pickup from a 1962 Fender Stratocaster.  The pickup was not producing any sound when installed in the guitar and when hooked up to a mulitmeter, showed no resistance.  This means that there is an open circuit somewhere between the positive and the negative lead wires.  It is important to be very careful when working on this type of vintage gear in order to preserve the original tones of the guitar, so a number of steps were taken to carefully diagnose the source of the problem.

First, upon removing the cover I could see that this pickup uses Formvar wire, a common wire of the period, which gives it that coppery look.  There is a thin layer of wax on the pickup meaning it was at some point wax potted.

I could see that the wire leading to the black, negative wire is leading to the center of the bobbin and the wire leading to the white, positive, wire is coming from the outside.  This means that the wire was wound onto the pickup in a clockwise direction. If you point your finger at the left eyelet where the black lead wire is connected and then follow the wire on a path around the magnetized poles about 8,000 times and then end at the right eyelet you can see that this pickup was indeed wound in a clockwise direction.

When I oriented a magnetometer over the poles I could see that this pickup is South up with an average of 27 gauss.  A bit too much magnetism for a bridge pickup for my taste, but in the interest of preserving originality I left the magnets alone.

Next I inspected the condition of the actual Formvar wire and I could see that there was no visible damage.  My next step was to heat up the solder on the eyelets and add a little bit more solder.  This connection can get dirty over the years and cause a bad connection.

Eureka!!  After doing that I tested the resistance again and sure enough this pickup is reading about 5.44 thousand ohms of resistance, just right.  I am done and the original tone of the pickup is preserved.

If heating up the eyelets had not worked my next step would have been to disconnect the finish and unwind a few coils to try to find a break.  As a last resort I would have removed all of the old wire and solder, rewound the pickup with vintage-spec wire and waxed it.

What happened to Sklar Guitars?

Well, nothing really.  It's still the same company, it's just now called Schuyler Dean Pickups.  I thought this would more accurately describe what I do and who I am.  Having an alter ego is fun, but sometimes confusing, and that's what "Sklar" was, an alter ego, a nickname, which I may still use when naming specific pickups, who knows. 

Schuyler (pronounced sky-ler) is my given name and I am proud of it even though it trips people up with the pronunciation sometimes.  But it is much harder to explain that, "My name is Schuyler and it is pronounced Skyler and the name of my company is Sklar which is pronounced the way it is spelled." 

And I also dropped "guitars" from the name because most of what I do is having to do with the electronics, specifically the pickups.

But I am still making pickups and enjoying every minute of it and you can call or email to talk about what kind of sound you are going for in your setup, or you can stop by and visit my at my other job at Cole Hardware in San Francisco. 

-Schuyler
415-238-7325
schuylerdeanguitars@gmail.com

Top Five ways to improve your tone

In honor of the movie (and book) High Fidelity here are the top five ways to make your electric guitar or bass sound better.

5.  electronics- 

this Stratocaster pickguard has copper shielding tape, 250k CTS pots, .022 uf orange drop capacitor, 5-way switch, cloth-covered wire, and Schuyler Dean pickups

This includes pots, capacitors, switches, jacks and shielding.  If you're building a guitar it is a good idea to not skimp on this part and if your doing something like installing new pickups it's nice to use quality electronics to carry the current.

• Shielding- it is important to have shielding grounded properly and surrounding the entire control cavity so that outside electrical interference can't get in.  typically luthiers use shielding paint on the wooden cavity grounded by a lead wire, and shielding tape on the back of the pickguard.  Everything is grounded in this circuit; the pots touching the pickguard shielding, the metal covers on humbuckers, and even the braiding on 2-conductor wire.  A wire is then run from the back of the pots to the bridge grounding the strings.  Ever notice how when you touch the strings the amp stops humming?
• Potentiometers (pots)- 250K pots are warmer and typically used for single coils and 500K pots are brighter and typically used for humbuckers.  No-load pots are louder and make the guitar sound brighter.  There are endless possibilities.
• Capacitors (caps)- The higher the number, the more bass at the zero setting on your tone control.  A .100 uf cap will sound warmer than a .001 uf cap.  Again the possibilities are endless.

4.  The Nut-

 a bone nut in a Fender P-Bass

This piece of shaped plastic or bone holds the strings in place at the zero fret for the correct string spacing.  Most are made of inexpensive plastic but you can get a nicer tone from bone or even brass for killer sustain!  You can only hear the difference when the strings are being played open of course.


3.  The Bridge-

the Stratocaster tremolo pivots on six body screws and is tensioned by three 

to five springs mounted on the bottom of the body.

There are many different types from the tremolo to the string-thru-body and they all add a bit of character to your guitar.  Brass saddles will typically sound a little nicer than cheaper steel ones.

2.  Pickups- 

Jazzmaster pickups get their fat tone from short "pancake" style 

bobbins and plenty of winds of copper wire.

All pickups really do is change string vibration into an electrical current, but they have everything to do with your guitar tone and how it behaves through the amp.  Good quality pickups like the ones I make will sound clearer and have more voice and character than cheap ones.  High-output pickups will be louder and produce more lows than brighter low-output pickups.

1.  Strings-

And the number one best way to improve your tone (aside from practicing) is to use new, high-quality strings.  Strings with more nickel will sound warmer, and strings with more steel will sound brighter.  You can also opt for flatwounds for an even warmer tone.  Larger diameter strings like .011's (on six string guitar) will be louder and warmer because there is more mass moving for the magnetic pickup to detect.  Old, dirty strings will not perform as well and sound dead so it is important to keep your strings clean and change them regularly.