Guide to Guitar Pickups

This is a guide to pickups and the wiring of electric guitars. It is part of a larger guide to constructing a solidbody
electric guitar. I would really appreciate any comments, questions, or suggestions that any of you have. My email
address is tmk@netmagic.net.

Standard disclaimer applies: If you use the info in this document, you do so at your own risk. If you hurt yourself,
someone else, your guitar, or anything else, then it is by your own choice and you are responsible for your actions.

What is a pickup & how do they work?
Variations
Basic wiring
One Pickup
Volume
Tone
Intermediate Wiring
Multiple Pickups/Switches
Multiple Volume/Tone Controls
stock diagrams
Advanced wiring
Humbucker tricks
Phasing
custom wirings
Links


What is a pickup & how do they work?

Pickups are the part of your electric or acoustic-electric guitar that convert the vibration of the strings to an electric
signal that goes to your amp, effects rack, or in some cases, recording equipment.

In solidbody electric guitars, the pickup is a magnetic inductor. The pickups are essentially magnets with wires coiled
around them. When vibrating strings move through the magnetic field this creates, an electrical signal is created
(induced). It is then sent through the wires and electronics of your guitar an out to wherever you plug it in. The
simplest form of these pickups are called "single coil" pickups, because there is a single coil of wire wrapped around 6
magnetic bars.

In acoustic-electric guitars, the pickups are what is called piezo-electric pickups (piezo for short - say pee-ate-so).
Piezo pickups are made out of a special material that emits an electrical signal when squeezed or compressed. For this
reason, they are generally mounted under the saddles in acoustic (and in some cases electric) guitars. When the strings
vibrate, the piezo elements are compressed, and the signal is sent out to your amp. The piezos re-create the acoustic
sound very nicely; this is how most of the electric guitars that claim they can sound like acoustics do it.

Variations

Rail pickups
Most single coil pickups have 6 magnets, one for each string. One drawback of this method is that in the spaces
between magnets, strings are not "picked up" as well as when they are above their respective magnets. So someone
decided to make a pickup with one long bar across the length of the pickup, so no matter where you bend the string to,
it will always come through loud and clear. These pickups are called bar or rail pickups. Some have one rail, some
have 2.

Humbuckers
The first pickups were of the single coil variety, but since the strings of the guitar and the electronics within make a
great antenna, there was always a lot of hum associated with them. Then, in 1957 or 58 Seth Lover of Gibson guitars
found a way to stop (or at least greatly reduce) the hum. Sound is a wave similar to the waves in the ocean, and if you
have waves that are equal but vertically opposite, they will cancel each other out. The "Humbucking" pickup has 2
single coil style pickups wired so that the hum from one pickup is the exact opposite of the hum from the other, but the
sound from the strings is not. Therefore, when the 2 signals are mixed, the hum cancels out, leaving you with only the
sound of the strings. Nowadays, Fender strats use the same principle in switch positions 2 and 4. That is why those
positions are quieter than positions 1, 3, and 5. Most humbuckers look like 2 single coil pickups stuck together, but
they are available in sizes that will fit a standard single coil slot.

Basic wiring

In the following pictures, a downward arrow means connect to ground, a plus sign indicates the "hot" wire, and a
minus sign the "neutral" wire. Try to look at each part of the signal path (the path the electric signals make from the
pickups to your amp) as a different "module". For our purposes, wiring and electrical design will be much simpler if
you consider everything in "modules" rather than looking at the project as a whole.

One single coil pickup.
Each single coil pickup has 2 wires coming out of it. If you are only using one pickup, then it doesn't matter which
wire goes to hot, and which goes to ground. (In real life there is one wire coming out of the pickup, which splits into 2
at the end, but for now, let's pretend that one wire comes out of one side, and the other out of the opposite side.) In
some cases, there will only be one wire, and a metal braid. Treat the metal braid as the neutral or negative wire. If there
are 2 wires and a metal braid, solder the metal braid to ground.

Consider this picture:

Volume
The volume knob works using a potentiometer, more commonly just called a pot. Pots are variable resistors, because
as you turn them, the electrical resistance changes. There are usually 3 lugs (wiring connections) on a pot, and to
understand what they mean, you need to know how pots work. This is the electrical symbol for a pot:

The lines on either side are the left and right lugs, the arrow is the middle lug, and the squiggly line is the resistor.
When you turn the knob, the arrow will slide either left or right, depending on which way you turn the knob. If
electricity is coming in from the right side, it must go through all of the resistor to get to the left side, but if it wants to
get to the middle lug, then it only has to go through as much resistor as it needs to.

For single coil pickups, use a 250K-ohm pot, for humbuckers, use a 500K pot. If you are mixing different types, use
a 500k pot.

The wiring is as follows:
Connect the wire from your pickup that you chose to be "hot" to the middle lug.
Connect a wire from the right-hand lug (as seen from the top) to the hot lug on your output jack.
Connect a wire from the left-hand lug to the ground lug on your jack.
Connect the ground wire from your pickup to the ground lug on your jack.

Here's a picture:

Note: This type of volume wiring is passive, it cannot boost the volume, it can only reduce it.

Tone
Tone knobs use something called a capacitor to "bleed" higher or lower (depending on how you wire it) sounds to
ground. As I understand it, they change resistance depending on the frequency of the sound that passes through them.
The standard values for capacitors are .05uF for strat style guitars, and .02uF for gibson style. [NOTE: These values
are now correct. They used to be far too small. Sorry for the mistake] Either will probably be just fine.

The wiring is as follows:
Connect the wire you chose to be the hot output to the center lug of the volume pot.
Connect a wire from the center lug of the volume pot to the left-hand lug of the tone pot.
Connect a wire from the right-hand lug of the volume pot to the hot lug on your jack.
Connect a wire from the left-hand lug of the volume pot to the ground lug on your jack.
Connect a wire from the left-hand lug of the volume pot to one end of a capacitor.
Connect a wire from the other end of the capacitor to the center lug of the tone pot.


Intermediate wiring

Switches/Multiple pickups
Now you're ready for a bit more of a challenge. Few guitars or basses have only one pickup, so how do you add
wiring for more? Switches. Switches allow you to select a single pickup or combine the output from many. Unless
you want volume or tone controls for individual pickups, it's easiest to send all the hot wires into your switch,
combine all the ground wires, and use the output of your switch as hot:


There are MANY different kinds of switches, but I'm only going to cover the standard Gibson and Fender switches,
as well as slide switches and rotary switches.

There are diagrams for each type of switch below.

You don't need to know how a switch works on the inside, but you do need to know which of its lugs are connected
in which positions.

Gibson uses 2 position throw switches, the kind that look like a baseball bat stuck in a hole. The 2 position switches
are SPDT On-On switches. SPDT means Single Pole, Double Throw. Single pole means that there is only one set of
lugs, and double throw means that there are only 2 positions that the switch can have. On-On means that both positions
are active, whereas an On-Off switch would mean that even if you connected wires to the lugs that are supposed to be
connected in that switch position, it wouldn't work.

The Fender 5-position switch is wired like a 3 position switch. I would call it a DP3T (Double Pole, Triple Throw)
switch. It has 2 separate sets of lugs controlled by one switch that can be in any of 3 positions. see the diagram to
understand how it works. There are switches that look like the Fender switch that are actually DP5T switches, Stewart
McDonald's has them if you're interested.

Slide switches are pretty straightforward, they are the on-off switches for most toys, and Fender jazzmaster, jaguar,
and similar models use them. In my guitar, I used one DPDT slide switch, and one DP3T. Both were used for coil
tapping my humbuckers(covered later - don't worry). See the diagrams for exactly how they work.

All DPDT switches are not equal, however. If you come across a DPDT toggle switch (baseball bat in hole style), it
will be wired differently than a DPDT slide switch. The differences are noted in the diagram, and are caused by
mechanical differences in the two.

Finally, we have rotary switches. Rotary switches are available in lots of different shapes and sizes, and are useful
because they offer more positions for the space they take up than most other switches. The Fender 5 position switch is
actually a DP3T rotary switch with some extra tricks. They are not included in the diagram, but are similar to the
Fender switch in that each selected lug will connect to a common output lug.

Finally, the long awaited diagram.



(the positions in red on the Fender switch indicate both lugs are connected)

Multiple Volume/Tone Controls
Multiple volume and tone controls are easy. For each pickup you want to have its own volume(and or) tone control,
follow the instructions from earlier, but connect the hot output(s) to the input lug on the switch for that pickup instead
of the jack. The ground outputs will still go to ground. Remember, anything you put between the switch and the
pickup will be for that pickup only, and anything between the switch and your jack is for any/all the selected pickups.
Think modular.

Stock diagrams
Strat Standard Diagram
Les Paul Standard Diagram

Advanced wiring

Humbucker tricks(Coil tapping & Parallel wiring)
Humbuckers come in 3 styles as far as wiring is concerned. Some have 2 wires coming out, some 3, and some have 4.
There isn't much you can do with 2 wire humbuckers - as far as wiring is concerned, they behave like single coil
pickups. With 3 or 4 wires, things get a bit more interesting. The extra wires are connected directly to the individual
pickups inside. This allows you to use either of the single pickups for that single-coil sound, but it will not be
humbucking. This is called coil-tapping. Or you can connect the pickups in parallel, which reportedly gives you a
different sound, but is still humbucking.

Phase Switching
The phase of a pickup is relative to other pickups. A single pickup cannot be "in phase" with itself. Out of phase
pickups will produce "waves" of sound that are vertically opposite, and out of phase pickups can cancel each other out,
giving you a really weak sound. (see the discussion on humbuckers for more info) Phase switching is useful if you
will be using all 3 pickups at once - chances are good that 1 pickup will be out of phase with the other 2, resulting in
unwanted cancellation. If you are going to use phase switching, plan out all the phases of all the pickups in all
selectable positions before you commit. Once things are soldered in the guitar, changes are much harder to make.

Custom wirings
Designing a custom wiring scheme is a lot of fun, and a lot of work. It will give you all the switching options you
want, and none you don't. For this guitar, I included all the options I could think of, kind of as a test to see which
ones I like. I have the ability to select any combination of pickups, parallel wiring on the neck humbucker, coil tapping
on both the bridge and neck humbuckers, and phase switching on the middle pickup. It was a lot of work, and it took a
long time to plan it, but it was well worth it. Now I am a wiring pro :)