PART ONE: MECHANICAL SET UP
1. File the
If you want a perfect action, no fret can be sticking up less or more than any other. I personally have never needed to have the frets filed on an electric guitar that I have purchased. They have all been done very nicely at the factory.
To check the frets, take a 4” straight edge,
slide it around on the frets and look underneath it. See if any light
shines through between the straight edge and the frets. See if it rocks. See if the end of
the straight edge gets stuck on a fret when sliding. If you see light,
if it rocks, or if it gets stuck anywhere on the neck, you
have a problem.
Also, on a used guitar, check the frets for wear -- especially the first three frets. If you have grooves but they aren't super deep, they can usually be corrected without replacing the frets (which is expensive to do) by having them filed.
If you need to have the frets filed, let a trained guitar luthier do this step. It requires special tools and knowledge. This is what the luthier will do:
Remove the strings
Use low tack drafting tape to protect the neck and fretboard
File with a mill bastard file with the convex side down
Every stroke, file from the center to the two edges
Then round the frets with a special file
Use a tiny paint brush to clean the filings off of the neck
Remove the drafting tape
Remove all six strings.
Get some clean cotton rags to use for cleaning. White flannel with no chemicals (cheap at a fabric/craft store) is best. Or a microfiber towel. Do not use anything that has been treated with fabric softener.
A good cleaner for urethane gloss and semigloss finish (which on most electric guitars is everything except the fretboard and possibly the back of the neck if the neck is unfinished) is Rosinol lighter fluid (or naptha, which is the main ingredient in lighter fluid). It cleans but doesn’t damage the finish. Second choice: denatured alcohol. (Note: naptha is highly toxic to breathe. Use a mask and have adequate ventilation.)
After cleaning, wax the guitar so that when you clean the neck all the little steel wool fragments will be repelled off the body and you won’t scratch the guitar with them. Any high quality non-silicone car wax will work well on an electric guitar. I use Turtle Wax “Ice” spray-on car wax. Another good wax is Turtle Wax Express Shine spray-on clear car wax. Do not use a wax or polish with a heavy silicone base. Do not ever put wax or polish on the fretboard. Don’t forget to wax the headstock (with the strings off). If your guitar’s neck is either painted or gloss urethaned on the back side, be sure to also wax the back of the neck. If the back of the neck is raw or dull finished, it’s usually best to just leave it, or perhaps to lightly polish it with dry 0000 ("four aught") steel wool going with the grain.
While all the strings are off, tighten the tuner nuts. Use a 10mm deep well socket. Don’t overtighten; just a little snug down. Also check the tension of the tuners. Turn the tiny screw in the end of the tuner button, clockwise to increase or counterclockwise to decrease resistance to turning, so that they are all have the same feel when twisting.
If you have a rosewood fretboard, use dry 0000 steel wool to clean the fretboard. You can get this at any hardware store. Don’t use any chemicals. Don’t rub the steel wool sideways. Go with the grain. When finished, sweep clean with a clean new soft paint brush.
After cleaning, apply oil to the rosewood fretboard. Boiled linseed oil works well. I personally use Music Nomad Fretboard F-ONE Oil Cleaner & Conditioner. It has no lemon oil extracts, waxes, petroleum distillates, silicone, or water. (Do not use Lemon Oil on the fretboard; lemon oil is highly acidic and also contains d-limonene, which is a strong solvent that is used to remove paint and glue. Both the acid and the d-limonene will dry out the fretboard.) Blot the oil into a paper towel. Don’t drench the paper towel. Just a thin coat is all you need. Don’t let it soak into the fretboard. As soon as it’s been evenly applied, then wipe off the excess with a clean cotton flannel rag.
If your fretboard is maple, there are varying opinions about care for maple fretboards, and I have no personal experience with them, so you’ll need to do your own research.
3. Put a
new set of strings on
Be sure to do the set up with a brand new set of the exact brand and gauge of strings you will be using.
Install the strings one at a time. I use a simple method of winding strings that is recommended by Taylor Guitars. Stretch out each string one at a time and cut it to length with a pair of dykes. Four of the strings should be cut to a length slightly longer than one tuning pin past the pin it goes into (E string cut just past the A pin, A just past the D pin…) For strings 3 and 4, just eyeball the distance where another pin would be past the end of the headstock. The plain steel (unwound) top three strings (1E, 2B, and 3G) I always cut just a little longer than the rest to get a couple more winds in order to push them below the bottom of the tuning peg hole (the sharp edge on the hole is where the string usually breaks). This method will give 3 windings on the thick wound strings and more on the thin bare strings. After cutting to length, insert each string straight through the hole so that it sticks out a few millimeters, bend the string with a sharp bend 90 degrees in the correct direction, and tighten with a string winder while holding the string with tension with the thumb and forefinger of the other hand. Make sure the winds go downward, not upward, and that they are even and snug against each other. There is no need to cross the string over itself. The shape of the tuning pin will push each wrap against the wrap above it, which will provide tension so the string will not slip.
NOTE: If you are using Pyramid pure nickel strings or any other vintage style strings with round core wires, you need to bend (crimp) the string before you cut it, or the winding will loosen and unravel as soon as you cut it, and you'll end up with a dead sounding string. Crimping the strings is easy to do. On the bottom three (wound) strings, simply measure where you want the cut, mark it with a Sharpie, insert the string through the tuner peg hole to where the mark is sticking out a few millimeters, and lightly bend the string around the peg. Then pull it out and with some pliers make the bend into a 90 degree sharp bend to "set the wrap." Then insert it through the hole again, and tighten it up all they way to the correct pitch. THEN cut the excess string off. The crimp and also the pressure on the strings on the peg when tuned to pitch prevent the string from unraveling. You don't need to worry about this with normal, modern style strings with hex cores, because they are wound so tightly around the sharp edges of the hex core wire that you can just cut them and they won't unravel.
Some people recommend the twist-under wrap method of winding strings onto the tuner pegs:
I have used the twist-under wrap method in the past but have found that the simple method described above holds the strings just fine and the guitar stays in tune just as well. The simple method is faster to install the strings and also easier to remove the strings when it’s time to change them, and it gives a cleaner, better looking wind.
After installing each string and partially tightening it, stretch the string. Start at the bridge. Lift the string with one hand. Use the other hand to stretch ¼th of the string at a time. Then move to the next ¼th, and so on. If you do this, it will stay in tune much better and not keep going flat during the first few days (making it “stage ready”).
General Information about Action:
Three things determine the height of the action (the distance form the string to the fret): truss rod tension, bridge height, and nut slot depth. These three things work together, and a change in one will often require a compensating change in another. In general, the lower the action, the easier the guitar is to play, but if it’s too low the strings will buzz.
Action is a compromise, based on personal preference. Are you willing to trade a lower action height for a little fret buzz, or are you willing to trade no buzz for a higher action? What is your playing style? If you’re a rocker, you’ll need a higher action, because strumming hard makes for more buzzing. With jazz, you can get away with a lower action. In general, you adjust the truss rod, then tweak the bridge, then file the nut and the nut slots, then adjust the rod again, then tweak the bridge again, and so on, until it is at the lowest point with no more buzz than you’re willing to live with. There is no right or wrong. If you feel comfortable with the buzz you have and with the action you have, then that’s fine! If you like it, then it's good!
previously mentioned, before adjusting the action, be sure
to put a new set of the strings you’re actually going to
gauges of strings have different
tension, which will pull the neck more or less and thus
change the action. Different
brands and types of strings even in the same gauge vibrate
differently and may buzz more or less than others because
the vibration width may be wider or narrower.
4. Truss Rod (neck relief):
The truss rod is a long bolt that sits in a
hollowed out slot in the neck. It is a very long bolt
that goes from one end of the neck to the other. The
purpose of the truss rod is to offset the tension of the
strings that tries to pull the neck upward. Without a
truss rod, the neck would bow into a concave shape. As
it is tightened, the truss rod pulls the neck downward, thus
offsetting the string tension and returning the neck to a
more neutral shape. Not all the way straight, but most of the
way. There has to be a slight concave curve.
If the neck is perfectly straight, the
strings will buzz like crazy. Because
of their shorter scale, Les Paul style guitars need a
little more curve than do Fender style electric
guitars. Different string gauges,
string alloys, and string winding methods result in
different amounts of string tension on the neck.
Additionally, age, humidity, and temperature changes affect
the wood in the neck. All these things necessitate
occasional adjusting of the truss rod to return the neck to
the "ideal" shape.
In practice, the truss rod determines the height of the action on the low frets (from the middle of the neck to the end closest to the headstock) by determining how much “relief” (a.k.a. “bow”) is in the neck. The closer the strings are to the frets, the lower the action is and the easier the guitar will be to play, but if it is too low the strings will buzz when you are playing on the low frets.
To measure your guitar's current neck relief, place a capo behind the 1st fret, and press down with your right thumb on the 6th string (low E) just above the top fret so that the string is touching the first and last frets. Use a feeler gauge (available at any automobile parts store) to measure the distance between the 6th string and the 8th fret. Try various thicknesses of the gauge, sliding one at a time between the string and the 8th fret until you find the one that fits perfectly with no play and without raising the string. The thickness of that gauge is the measurement.
Then check the same measurement on the 1st string (high E). The measurement for the two strings should be close to equal. Based on my own experience, and my personal preference for a low action, I have found that if the saddle height is as low as possible, and the frets are equal height, and the neck is straight, with the capo on the 1st fret and the string pressed onto the last fret, then the distance between the string and the 8th fret should be appx. .020” on an L.P. style electric guitar. This is how much the neck is bowed inward at the center of the neck. .020” will yield a nice low action with only a little string buzz. (With a low action, some buzz is normal. All Les Paul style guitars buzz a little. In my opinion, if it’s not coming through the amp, it is nothing to worry about.)
To adjust the neck relief, first locate and expose the truss rod bolt head. On some older Fender style guitars it's hidden and hard to reach, but fortunately on most L.P. style guitars it's easy to access, usually under a small plate in the headstock just above the nut. Remove the two or three tiny Phillips screws, remove the plate, and you'll see the Allen style head of the rod. Your guitar should have come with an Allen wrench that fits it. If not, find one, and keep it in your guitar case, along with a small Phillips screwdriver.
if the measurement is larger than you want,
turn the truss rod bolt clockwise to tighten the rod, which
will lower the strings and decrease the neck relief.
Or if the measurement is smaller than you want, turn the
truss rod bolt counterclockwise to loosen the rod, which
will raise the strings and increase neck relief. It is
recommended to loosen the strings slightly before adjusting
the truss rod to reduce the pressure on the threads so you
don’t strip the threads. I personally prefer to hold
the guitar against my chest and simply bend the neck back
while turning the wrench to relieve pressure on the threads
while turning the wrench in either direction.
Adjust the rod 1/6 of a turn at a time (one face of the Allen head) then check the measurement and check the action for buzzing (if you loosened the strings you have to re-tune them before checking.) Then check again after 10 minutes to let the wood settle to the new tension (wood is slower to settle in than steel). You can speed up this process by putting one hand on the headstock and the other hand on the body and pushing the neck in the direction you’re trying to make it go (backward if tightening the rod and lowering the action, forward if loosening the rod and raising the action).
5. Bridge Height:
The height of the bridge determines the height of the action (distance from the string to the frets) on high frets (from the middle of the neck to the end closest to the neck pickup). Like with the truss rod, the smaller that distance, the lower the action is and the easier the guitar will be to play, but if it is too low the strings will buzz when you are playing on the high frets. To measure the bridge height, place the guitar on its back with no weight on the neck. Measure the string to fret gap at the 12th fret with feeler gauges.
Various web sites suggest various action heights. One suggests a low action would have .078” on string 6 (low E) and .063” on string 1 (high E) at the 12th fret, while .125” on string 6 and .094” on string 1 would be considered a high action. (Typically, you can have the high E around .015” to .030” smaller gap/lower than the low E.)
Personally, I prefer to go a tiny bit lower than their suggestion for low action. My action as measured by open string height at fret 12 is .060 on high E and .075 on low E, and I love it!
On an L.P. style guitar, bridge height is adjusted by turning the two screws that mount the bridge to the body. Clockwise to lower the bridge and reduce the string height at fret 12, counterclockwise to raise it.
6. Nut slot depth:
Nut height and nut slot depth affects string height at the end of the neck closest to the headstock, for open strings that are not being fretted with your fingers. The objective is to get as low as you can without the strings buzzing when they are played hard, when “open” (with no fretting). This is a tricky and somewhat time-consuming process.
Measure the distance from the string to fret 1 with a feeler gauge. Based on a lot of experimentation, and my own personal preference for a very low action, the lowest you can go on an L.P. style guitar is:
1E 2B 3G 4D 5A 6E
.010 .011 .012 .014 .016 .018
This provides little margin for error. Any lower and the strings will buzz. A (barely) safe margin would be .002 more than these numbers:
1E 2B 3G 4D 5A 6E
.012 .013 .014 .016 .018 .020
This is where my own L.P. style guitar is right now; it plays like butter and, with the strings I’m using (Pyramid 10-48 round core pure nickel), there is no buzzing.
This is MUCH lower than the way most inexpensive L.P. style guitars (and also most Gibsons) come from the factory. For example, when I purchased my newest guitar, after adjusting the truss rod and bridge, I measured the open string clearance at the first fret, and this is what I found:
1E 2B 3G 4D 5A 6E
.020 .023 .032 .023 .024 .023
Wow. That was ridiculously high! I started by
filing down the bottom of the nut, very carefully, very
slowly, with many test measurements, to get the two outside
strings to my goal. To
do this, I loosened all six strings about 2 ½ turns, pulled
them off the nut, removed the nut from the guitar (this can
be tricky the first time; there are YouTube videos out there
showing how to do it).
Then I used 60 grit sandpaper on a flat surface and
rubbed the nut on it. (I like 3M sander sheets; they are
used an ultra fine Sharpie to make a mark for how much I
calculated I should sand off.
I never went more than half way on that mark before
reinstalling the nut and tightening the strings and
did this over and over and over again. It took hours, but
the result was worth it.
you go too low, you have to start all
over again from scratch with a brand new nut.
Another thing to watch out for: On one guitar, I sanded down a nut to perfection (I thought). The next day, the guitar was buzzing like crazy. I remeasured, and guess what? The nut had settled into the neck overnight and all my strings were .005” lower than they had been the previous day. So when you are getting close, make sure the nut is seated and smashed down with the strings fully tuned and let it sit a few minutes to settle, then play the guitar a few minutes, then measure again, before deciding to sand any farther!
After going through this process on my newest guitar, this is what I ended up with:
1E 2B 3G 4D 5A 6E
.012 .019 .026 .020 .021 .020
As you can see, both of the outside strings were exactly where I wanted them. I then needed to hand file string slots 2-5, one at a time, very slowly and carefully, with many test measurements, to get all six slots to my goal:
1E 2B 3G 4D 5A 6E
.012 .013 .014 .016 .018 .020
To do this, you need to have a set of files that are the same widths as the gauge of the strings. These special nut files are very expensive. What I did was take a feeler gauge and with a Dremmel tool I carved teeth into all the measuring spades. In essence, I turned my feeler gauge set into a set of files of various widths. I’m not sure if I recommend this to anyone else, but it worked for me.
If any of this sounds too difficult for you, I recommend that you have a guitar luthier do it for you.
Some people have a different opinion than I do about nut height. They say to put a capo just above the 2nd fret (below the 3rd fret) and measure the clearance between the bottom of the string and the 1st fret. They say there should be some space at 1st fret. If there is no clearance they say there will be buzzing. How much clearance? One web site says .010”. If it’s more than .010” you can cut the fret deeper. I personally prefer the direct measurement method.
After your nut slot depth is finalized, check to make sure that the three wound strings (4G, 5A and 6E) have 1/3 of the string exposed, raised above the nut. If one is not exposed enough, file the top surface of the nut to expose more of the string.
After finalizing the nut height and the nut slot depth, play the guitar and see how it feels and how much it buzzes. Then go back and tweak the truss rod and bridge height. Experiment until you get the action just the way you like it.
After the nut height, nut slot
depth, truss rod, and bridge height are set up, tune the
strings perfectly, then test the octave of each string to
see if it is in tune (finger the 12th fret). If the octave is sharp, you need to
make the string longer. If it is flat, you need to
make the string shorter.
On L.P. style guitars, the bridge has a separate "saddle" for each string. The saddle is the highest part of the bridge where the string touches. Each of those six saddles is individually adjustable to slide back and forth, in order for each string to be lengthened or shortened. Under each string, in the side of the bridge facing the pickup, there is a little screw (usually flat blade). If the octave is sharp, you need to make the string shorter by twisting the screw clockwise to move the saddle forward towards the neck. If the octave is flat, you need to make the string longer by twisting the screw counterclockwise to move the saddle towards the tailpiece. (When going counterclockwise, push on the head of the screw while you twist, to make sure the saddle is moving and the screw is not just loosening.) Twist a few turns, re-tune the string, and test the octave again. With trial and error, you'll find the perfect spot where the open note and the fretted octave are equally in tune on your tuner display.
Joe Bonomassa claims it gives the Les Paul more sustain if you bolt the tail piece all the way down and top wrap the strings around it. Supposedly the benefit comes from increased vibration transfer to the body resulting from bolting the tail piece solidly down onto the body. Other people online claim that either top wrapping or simply raising the tailpiece to reduce the angle of the string bend over the bridge allows the strings to ring a little more, which adds some extra harmonics.
On the other hand, most Les Paul setup instructions say to do the opposite. They say for maximum sustain to lower the tail piece as far as possible without the string touching the bridge: “The tailpiece should just be lowered enough so that the bass strings just do not touch the bridge for maximum sustain. The tailpiece can be offset a little higher on the bass side.”
The best expert I know told me
that top wrapping or raising the tailpiece will only improve
the sound if you are using heavy gauge strings like Joe
Bonomassa uses (which are hard to bend and stiff to play). If you top wrap
or raise the tailpiece with light gauge strings, there is
not enough bend in the strings at the bridge to put enough
pressure on the bridge to transfer the tone to the body. With normal and
thin gauge strings, the opposite of what Bonomassa says is
true: a steep angle helps.
The height of the tailpiece is adjusted with the two giant flatblade screws in the end of the tailpiece. Clockwise lowers it; counterclockwise raises it.
9. Speed Knobs:
With pull pots (discussed below), the stock Gibson style knobs are too hard to grab and pull quickly during performance, especially when holding a pick. If you are using pull pots, the cheapest and best modification ever is to buy some “speed knobs” which are much easier to grab and pull. Even if you are not using pull pots, speed knobs are easier to grab and turn. Many colors are available on Amazon and Ebay, but be careful: not all speed knobs will fit your guitar. There are different sizes of pot shafts on guitars, but nearly all L.P. style guitars have pots with a 6mm diameter “split shaft,” meaning there is a split in the middle and splines on the outside, and the knob is held on with friction, not with a set screw. The bigger problem is the number of splines. Some knobs have 18 splines inside and are called “coarse” knobs. Other knobs have 24 splines and are called “fine” knobs. To know which you need, look at the pot shaft and count the splines. Coarse has 8 on each side of the split (16 total, which is 18 minus 2 for where the splits are.) Fine has 10 on each side of the split (20 total, which is 24 minus 4 for where the splits are). Do not get the wrong knobs for your pots; they will not fit!
10. To Prevent Switch, Knobs, and Jack from Loosening:
Loosen the pickup selector switch nut, the output jack nut, and the four pots’ nuts. Paint the threads with clear fingernail polish and reassemble. This will prevent them from coming loose.
PART TWO: ELECTRONIC SET UP
11. Audio vs Linear Taper Pots:
Most Les Paul style guitars come with linear taper pots (look on the back of the pot to see which type you have: "A" means “audio” and "B" means linear; for example B500K means linear taper, 500,000 ohms).
Most people who try audio taper pots prefer them, but only if they are a good brand. If not, they are lousy. You have to spend more for a good quality true audio taper pot. Bourns and PEC make good ones. Alternatively, you can modify a linear taper pot with a feedback resistor to give you a reasonable approximation of an audio taper response. Here is a great article on this topic: http://www.geofex.com/article_folders/potsecrets/potscret.htm
Personally, I don't want to mess with it so I just buy quality Bourns audio taper pots. They work great.
What is the difference between linear and audio taper? A linear taper pot rolls off the actual volts (and therefore, the actual volume) evenly. As you turn the knob down, the drop off of actual volume is smooth. However, human beings don't hear changes in volume evenly. As volume increases, we notice increases less and less. Some experts say it takes as much as 10 times as much actual volume for us to perceive a doubling of volume. Thus, although linear taper pots roll off actual voltage and volume smoothly, they seem to roll off the volume very slowly at the beginning, and then faster as it goes. The change at the beginning (10 to 7 on the knob) sounds very slow and barely noticeable. Then as we turn the knob down more, we perceive the volume dropping very rapidly at the end (3 to 0).
In contrast, with audio taper pots, the actual voltage and volume drop in a logarithmic manner: very rapidly at the beginning (10 to 7) and then very slowly at the end (3 to 0), but the roll off seems smooth to our ears, with a perceived drop that is equal at the beginning (10 to 7), in the middle (6 to 4), and at the end (3 to 0).
On a clean sound, the purpose of the volume pot is to actually control volume, and audio taper works well for this because it gives smooth control of perceived volume. But on a distorted amp, turning down the volume doesn’t really decrease the actual volume coming out of the amp very much. Mostly, it reduces distortion and cleans up the sound. This is where opinions vary. Some people say dialing back distortion in the amp is smoother with a linear pot because an audio taper drops the output too rapidly at the beginning of the turn to get a smooth transition, whereas the linear dials back volume more slowly/smoothly at the beginning of the turn, providing fine “shades of dirt.” Critics of this idea (including me) say that with linear taper most of the “cleaning up” happens below 3, and it is very sensitive in that range and, therefore, hard to control.
In contrast, with audio taper, the “cleaning up” happens quickly and linearly. Some people (including me) like this because they want a fast response to pull back distortion and don’t want to turn the knob so far to get the reduction of distortion. One guy said, “I find audio taper easier to use in a gigging situation because most of the change is at the useful end of the volume pot, so smaller adjustments are required. I find cleaning up by going from 10 to 5 a lot easier than cleaning up by going from 10 to 2, which can be hard to find in a split second in the middle of a song when you're not actually looking at the guitar - you have to go to 0 then roll it back up!” A friend of mine who uses audio taper likes to set his amp to feedback at 10, screaming solo at 9, and when he dials volume to 5 he gets a clean sound.
I strongly prefer audio taper volume pots. They seem much more usable, logical, and musical to me than linear. After doing some research, I concluded that Bourns “premium” audio taper pots are the very best on the market. These pots use a conductive polymer resistor, instead of carbon, that is accurate and very quiet, and doesn't wear out like carbon does. They make two types: the black 95 “Premium” pot and the blue 82 “Vintage” pot. The 82 is a little bigger and costs a little more than the 95, but lasts longer and has easier solder tabs, and that's the one I use for my volume knobs. They are expensive but they work really well, are completely silent, and should last a lifetime.
The only bad thing about the 95
and 82 premium pots is that Bourns does not offer them with
DPDT switches, which are needed for various modifications
that are discussed below.
Bourns does make some reasonably priced audio taper
pots that use carbon media that have DPDT push-pull
switches. They are not as good as the premium pots,
but they are decent quality. That's what I use for my tone knobs.
One more thing to be aware of when
buying pots is the length of the shaft. Guitar pots are
offered in two lengths: “short shaft” (the threads are appx.
3/8”) or “long shaft” (the threads are appx. 3/4”). Not all L.P.
style guitars use the same length pots. Before buying
pots, make sure you know which length your guitar uses.
When replacing pots, be sure to solder the ground wires correctly. Any "cold solder joints" will cause noise, or damage tone, or come loose. I highly recommend the use of a 50W soldering iron (and some rosin flux). A 30W iron can't heat the back of the pot hot enough to bond it to the solder; and even if it could, it would take so long to heat the joint that it could damage the pot.
12. True Bypass Tone Pots:
To get a tiny bit more brightness when the tone knob is all the way up, you can modify your tone pots so that when turned up all the way (10 position) the signal is completely disconnected from the capacitor (true bypass). This is done by removing the back of the pot and using an Xacto knife to scratch/scrape off the carbon on the pot at the full volume position. This is nice in theory, but there’s a problem: to do this, you have to disassemble the pot… and you can’t disassemble Bourns premium pots (they are sealed), nor a push-pull pot with a DPDT switch mounted on the back. Besides, the difference would be so small as to hardly be worth the effort.
13. Modified Treble Roll Off Tone Capacitor:
The capacitor in the stock tone circuit is a high pass filter. That means only the high frequencies pass through, and the bass frequencies are cut off. But because the capacitor is wired to ground, the effect is opposite: it acts as a low pass filter in the signal path because it bleeds off the treble to ground. Thus, the high frequencies are dumped to ground, while whatever tones remain (low frequencies) continue on to through the volume control and out the jack to the amp. This is why the circuit is called a low pass filter, because the lows "pass" through the circuit while the highs are eliminated.
The value of the capacitor (mF or uF) determines at what point in the frequency spectrum the frequency cut-off occurs. The higher the capacitor value, the lower the frequency of the cut-off point. In other words, higher capacitance value caps will make your tone darker when the tone control is set below 10, because in addition to very high treble frequencies, some upper midrange frequencies will also be dumped to ground as the tone knob is turned down. Les Pauls generally have .047 uF caps, although most L.P. clones use .022 uF. Various people use caps as high as .068 uF and as low as .010 uF. Personally, I prefer the .022uF.
The amount of reduction of treble tones above that frequency is determined by the value and position of the pot (and this, of course is affected by whether the pot is audio or linear taper, as discussed above).
The bottom line is this: If you don’t like how your guitar sounds when turning down the tone knob because too much upper midrange is being cut, so it sounds muddy and lacking definition, and you find yourself wishing the tone knob would only attenuate the very highest treble frequencies instead, you can choose a smaller capacitance value capacitor. This will make the elbow of the curve a higher frequency, so that turning down the tone knob does not make the sound as muddy. Conversely, bigger capacitance value capacitors will roll off more upper midrange tones.
In addition to reducing treble as the tone knob is turned down, the capacitor also has another function in the circuit. When the tone knob is turned all the way up (to 10), the capacitor acts as an inductor that improves the tone of the guitar. Gibson’s web site explains it this way: “When rolling a tone control all the way back, the capacitor forms a resonant circuit with the pickup that provides a midrange boost.” The reason guitar experts use big, fat, high voltage capacitors instead of smaller ones is increased inductance. A .022 uF 400V capacitor sounds better than a .022 uF 25V capacitor even though they have the same capacitance value (and even though guitar circuit voltages are measured in millivolts).
Different brands and types of capacitors make the tone circuit sound different, even if they are the same capacitance value and voltage rating. Cheap ones can be very inaccurate and can vary in capacitance +or– 20% from their stated value. Also, with cheap capacitors, capacitance can vary with frequency, temperature, and applied voltage. Some cheap capacitors are even microphonic, which means they make noise when the guitar is moved. If the capacitor value is inconsistent, the resonant peak created by the capacitor can have a different frequency at different times. All this can make the guitar sound different under different conditions. All L.P. knock offs, including Epiphones, and even most Gibsons, come with cheap capacitors.
Sprague Orange Drops are generally
considered a very good upgrade capacitor for the price. They offer
stability, resistance to temperature variation, low moisture
absorption, excellent characteristics in AC circuits, no
microphonics, and therefore consistent tone. The Orange Drop
“715” (600V) is the current production capacitor that is
recommended by most people.
The Orange Drop “716” (400V) has more flexible copper
leads and costs more but some people say it doesn’t sound as
good because it is compressed during manufacturing so that
it is not round in shape. I
found a pair of NOS Orange Drop 418’s (600V .022uf) on Ebay
for super cheap. Some
people say they sound even better than the 715’s. All I know is
they sound great in my guitar.
Replacing capacitors is an easy soldering job. Just remove the existing caps and solder the new ones in their place.
14. Capacitor Markings:
Modern Orange Drop and other newer capacitors are not intuitive to read the value. Instead of traditional uF markings, the value is stated as a 3 digit number: 2 digits, followed by another digit that indicates how many zeros to add on to get picofarads, followed by a letter that indicates tolerance.
micro is uF = .000001F (1 millionth of a farad)
nano is nF = .000000001F (1 billionth of a farad)
pico is pF = .000000000001F (1 trillionth of a farad)
102J means 1,000 pF which is 1 nF which is .001 uF
682J means 6,800 pF which is 6.8 nF which is .0068 uF
123J means 12,000 pF which is 12 nF which is .012 uF
473J means 47,000 pF which is 47 nF which is .047 uF
(J is + or – 5%)
15. Treble Bleed (aka Treble Compensation or High Pass Filter):
With “modern wiring” (with which nearly all Les Pauls and L.P. clones have come from the factory since the mid 1960s), as you turn down the volume, the treble decreases, making the tone darker. I’m not completely clear on the reason why. All I know is when you turn down the volume (even just a bit), the high end or treble loss is not proportional to mid and bass reduction. A small cut in volume creates a far greater reduction of treble than of bass.
One way to deal with this annoying treble loss is to install a “Treble bleed” capacitor. The Treble Bleed cap goes across the terminals of the volume pot. It acts as a high pass filter that allows treble to bleed across the volume pot and not get turned down as much when the volume is turned down. There are three types:
above and right below) is simply a high pass filter. It seems
stupid to me because it allows the full treble to always
go to signal path no matter where the volume knob is. In other
words, the volume knob won’t turn down the volume of the
high frequencies at all.
(Including if the volume is turned all the way down!) Another
problem is selecting a value for the capacitor. Premier
Guitar recommends a 300-500pF capacitor (silver mica),
while the diagram above recommends .002mF, which is 4-5
times as big. So,
who is right?
“Kinman” (center in both of the above diagrams) does the same thing as Simple, but the addition of the resistor makes the effect less drastic. This one makes more sense to me. But again, opinions on what size of capacitor and resistor to use vary widely. The diagram above recommends a .0012uF with a 130K resistor. Premier Guitar also recommends a .0012uF silver mica capacitor and a 130K resistor. But someone else online said “2A123J (.012 uF, which is 10 times as big!) cheap green capacitors work, and you can try any resistor you want.” Again, who to believe?
“Duncan” (left in both of the above diagrams) is also less drastic than a Simple, but it additionally modifies the effectiveness of the pot in turning down the mid and bass frequencies. DiMarzio recommends the Duncan style with a 560pF capacitor and a 300K resistor. However, the above diagram recommends a .002uF capacitor (4 times as big) and a 100K resistor (3 times as low). Premier Guitar recommends halfway inbetween: a .001uF capacitor and a 150K resistor. Once again, it is hard to know who to trust.
All of these options are very easy to install. Just solder the capacitor (and resistor) to the terminals of the volume pot as shown in the diagrams. But all of them seem to have problems from a common sense standpoint. It seems to me that they have the potential to create the opposite problem: as you turn down the volume, the treble increases and the tone becomes brighter!
A fourth option is proposed online by someone named Frank Falbo. It seems to make the most logical sense to me. He doesn’t like the three common Treble Bleed circuits because he claims they don’t work for clean jazzy solo stuff with the tone control down. He says, “The problem is when you've got the tone knob down, and you're working the volume knob, at the tone knob you're cutting the highs, while on the volume side you're letting the highs pass through while reducing the lows, so you're sucking tone from both ends.” His solution is instead of the high pass cap jumping across the volume pot, the high pass cap runs through the tone pot (see diagram below). This makes the tone pot into a double purpose pot. One side of the wiper still controls the amount of treble cut from the tone knob, while the other side controls the amount of treble added through the Treble Bleed cap. When you have the tone knob all the way up, there is no change. The pickup hot is feeding 100% through the Hi-Pass cap to the center lug, and everything is as it was. But as you turn the tone pot down, the Hi-Pass cap becomes less and less "connected" to the pickup hot (due to the tone pot's resistance increasing) and therefore allows less and less "Hi-Pass" filtering to occur. Eventually, when the tone knob is all the way down, the Hi-Pass is disengaged. This makes the tone knob totally usable even when you're also playing with the volume knob.
Some people claim that a treble bleed circuit is the worst thing in the world and that it will destroy the tone of good pickups. Pickup manufacturers say this is a massive over-statement, and that most people who try treble bleed circuits with correct sized capacitors and resistors find them to be a good improvement with little or no perceptible tonal trade-off. Personally, I decided to not do any of these high pass treble filter options, because I am more impressed with the other option for fixing the treble drop problem: Vintage Wiring (below).
16. Vintage Wiring:
“Vintage wiring” is another way to get rid of the treble loss when turning down the volume pot.
With “modern wiring” (see
below), the tone control receives its signal from the
input of the
volume pot. Thus,
it is connected directly to the pickup. This wiring
scheme results in the nonproportional treble
attenuation when turning down volume discussed in the
With “vintage wiring” (see below), which was used in Les Paul’s in the 1950s and early 1960s, the tone control receives its signal from the output of the volume control (i.e., the wiper of the volume pot… unless you use volume knob isolation, discussed below). In this method, the voltage going to the tone circuit is always equal to the voltage going to output, no matter how the volume knob is set. This makes the effect of the tone circuit proportional to the volume, regardless of where the volume knob is. Therefore, turning down the volume does not increase the percentage of the treble signal that goes to the tone cap and pot, and therefore, when you roll down the volume control, you don’t have a disproportionate treble roll-off.
I have a friend who owns a 1964 Gibson SG, and it came from the factory with vintage wiring. He likes it so well that he has re-wired all his guitars this way. It eliminates the treble loss without the need for a treble bleed (discussed above.)
“Orpheo” at Seymour
Duncan says, “Is there a ‘best way’? It
really depends on your guitar, pickups and playing
modern wiring will maintain the overall volume
better when you roll down the volume but at the
cost of losing a bit of high end. If you
have a bright pickup that may not seem that bad of
an idea, because with less volume and the same
amount of treble the tone might be too piercing. On the
other hand, the vintage version keeps the amount
of treble the same but drops a bit in volume as
soon as you roll down the tone pot. What
you might prefer is very much subject to personal
This is a super easy modification to do. Just unsolder the capacitor from the left terminal on the pot and solder it to the center terminal.
I’m very fond of the 50s wiring myself. I have modded my guitar to have vintage wiring, and it works great.
17. Isolation of Volume Pots (AKA Independent Volume Controls):
With stock wiring (either modern or vintage), when both pickups are engaged (i.e. when the pickup selector switch is in the center position), when you roll down the volume of one pickup, even slightly, while leaving the other fully open, this makes the latter much louder than its mate. Even worse, backing down just one of the volumes to zero shuts off the entire guitar. This happens because the pickups are wired in parallel to each other so the two volume controls interact, so that if you roll off the volume of either pickup, it affects both pickups rather than just the one you turned down. This is very annoying. It eliminates part of the advantage of having separate volume controls for each pickup (in fact, with the switch in the center position, you would have better control with just one master volume circuit.)
There is a
simple modification that cures this. On each
volume knob, instead of wiring the middle (wiper)
lug to the output and the left outside lug to the
pickup, you can wire the middle (wiper) lug of the
volume pot to the pickup and the left outside lug
to the output.
This trading of input and output lugs will
“isolate” the two pickup circuits so that turning
down one pot won’t reduce the volume of both
why it works: With stock wiring, the more you turn
down the bridge pot, the less resistance to ground
there is going from the neck pickup through the
bridge pot to ground. But with the isolation
wiring modification, if you turn down the bridge
volume pot, there would still be 500K resistance
to ground going from the neck pickup through the
bridge volume pot.
This is another easy
modification to do. Just unsolder the wires
going to the volume pot, trade them, and resolder.
There is a downside to this modification: as you turn down volume (with the selector in any position), it will change the impedance to ground. “Orpheo” at Seymour Duncan says, “in the middle position you are allowed to dial in the exact tone you want without sacrificing volume. In theory, this might sound neat, but it does take out a huge amount of your high end.” In other words, it makes the treble bleed problem discussed above even worse. This is because when the volume pots are wired backwards, they “see” less resistance, while the output impedance rises. This results in dramatic treble loss when you roll back the volume.
I do find it very annoying that if you turn down one pot all the way, it kills the volume of both pickups, even if the other one is still turned all the way up. But this volume pot isolation modification would defeat the improvement gained from vintage wiring, and make the treble loss problem even worse. So I don’t use this modification in my guitar.
18. Pickup Height:
For hottest output, if you press the string at the highest fret, then measure the distance from the neck pickup at the pole to the bottom of the string, the distance should be 1/16”.
However, there are several advantages of having a distance of 1/8” to 1/4”:
1) to prevent “magnetic dampening” which is when the magnetic force of the pickup pole piece slows down the vibration of the string. That will kill sustain and tone.
2) to reduce string buzz by taking some magnetic pull off of the strings that pulls them toward the frets.
3) to adjust the relative volume of the two pickups by raising or lowering the hotter of the two.
4) to brighten and sweeten the tone. A pickup too close to the strings will be thick and dark. Moving it farther away from the strings will brighten it up.
So, if you have a neck pickup that is too dark or too loud or both, this is the solution! Lower the pickup to thin the tone and lower the volume. Turning pickup mount screws clockwise will raise the pickups and counterclockwise will lower them.
A variation of this is when you lower the pickup, you can raise the pole piece screws about 1/8” to 3/8” out of the top of the bobbin. This makes the screw coil “hotter” (louder) than the slug coil, which has two benefits: first, it makes the output of the pickup stronger when using coil cut (explained two sections below), so that it’s not as big of a drop in volume when switching to coil cut; and second, many people say that unbalanced coils make a humbucker sound more open and sweeter. Another way to accomplish the same thing is to tip the entire pickup a little. I like the way my neck pickup sounds when tipped this way.
Final adjustment to make each string equal in volume to the other strings can be done by adjusting the height of each individual pole piece screw. The poles are like mini volume controls for each string. You can stair step with the thinnest strings closer to the screw and the thickest farther away. Step up from E to A then D. G might be a little lower again or the same as D. B should be the same as G, then high E should again step up. In general, it is not recommended to turn any of the screws in so they are below the face, and most people say low E should be almost flush. Turning pole piece screws clockwise will lower them and counterclockwise will raise them.
I have found that with the pure nickel strings I’m using, the three lowest strings (the wound strings) do not have as much magnetic energy and thus are lower volume than the three upper strings (the plain steel strings) and so I have raised the screws more on the lower three to offset this characteristic.
Rough adjustment from side to side can also be done by tipping the pickup slightly sideways, by adjusting one pickup mount screw slightly higher than the other.
Lowering the neck pickup helped mine tremendously. It made the two pickups closer in volume to each other, and it made the neck pickup brighter and less heavy on bass. I also tipped the neck pickup slightly so that the screw pole is closer to the strings than the slug pole.
A Note about Humbucker Pickup Theory and Terminology:
A traditional humbucking pickup is comprised of two separate coils, which are wired in series. Commonly, one of the coils will have adjustable “screw” pole pieces (designed to give an adjustment for string-to-string balance, as mentioned in the previous section), and the other coil will have non-adjustable “slug” pole pieces. These two coils are connected out of phase, and are reverse (magnetic) polarity from each other - which means they are in phase sonically. The reason it’s called a “hum bucker” is because magnetic energy from the string’s vibration is created in phase, but the out of phase wiring of the two coils will cancel most nonmagnetic radio-frequency noise, hum and interference.
Think of it this way: the two coils are wired opposite each other, and they also have their magnets placed with reverse polarity to each other. For this reason, the two “finish” wires both come out the same side of the guitar as each other (one goes to signal and the other to ground) and the two “start” wires both come out the other side (and are wired together). Even though this makes the two coils out of phase with each other, it works because the reversed windings and magnet polarity reverses this and puts them back into phase.
Pickup terminology is very confusing. In normal Gibson wiring, the South/Screw coil is the coil that the “-” (or “ground”) lead is connected to ground. The North/Slug is the coil that the “+” (or “hot”) lead connects to the signal path. And the South/Screw “+” (or “hot”) lead is connected to the North/Slug “-” (or “ground”) lead. But with different terminology, the South/Screw is the coil that the “Finish/Inside” lead is connected to ground. North/Slug is the coil that the “Finish/Inside” lead connects to the signal path. And the South/Screw “start/outside” lead is connected to the North/Slug “start/outside” lead. Thus, + and - do not translate to start and finish. In fact, the definitions are completely different and half the time they are reversed! I’ve decided to ignore any diagram that uses + and - . I only use the start & finish terminology, which seems to be used by the more sophisticated/informed electric guitar crowd.
19. Coil cut (aka: coil shunt, coil tap, coil split, single coil switching):
Coil cut is a method of wiring that changes a humbucker into a single coil pickup. This drops the volume and makes the sound “chimey,” brighter, and less fat, like a Strat. Wiring this modification isn't hard but takes some dexterity. All you need is one "push-pull" tone pot that has a DPDT switch attached. You easily can buy pots with switches on Ebay. The two wires from the neck pickup that are connected to each other and not connected to anything else (the South start and the North start leads) get soldered to the center terminal on one side of the switch, and ground goes to the terminal directly below it. The two corresponding wires from the bridge pickup get soldered to the center terminal on the other side of the switch, and ground goes to the terminal directly below it. When the switch is “on,” this grounds both ends of one coil, while leaving the other coil active, effectively making a humbucker into a single coil pickup.
My L.P. clone came from the factory with coil cut, using two DPDT switches (one to do coil cut on neck and the other to do coil cut on bridge). But it only takes one DPDT switch to do a coil cut on both pickups. Because I’ve very seldom found situations where I wanted one pickup in single coil mode and the other in humbucker mode at the same time, I wired both pickups to one switch so I only have to pull one switch to do coil cut in both pickups. This freed up the other DPDT switch for another purpose, which will be explained below.
In normal Gibson wiring (screw coil goes to ground; see the privious section), if the start-to-start jumper wire is grounded by a coil cut switch, that would leave the slug coil active. There are two advantages of grounding the screw coils and leaving the slug coils active during coil cut: First, the slug coils are the two that are closest together, which will give them more “quack” when in the center switch position during coil cut. Second, on the bridge pickup, the slug coil is farther from the bridge than is the screw coil, which gives it more output and warmth than the screw coil in the "Treble" or bridge switch position.
On the other hand, there
are two advantages of having the screw coils
active during coil cut. First, during coil cut, the
screw pickup, which has been individually adjusted
for string volume, is the active one, so those
adjustments will be active during single coil
if we’ve made the two coils unequal by screwing
out the screws 1/8-3/8” (or tipping the coil), the
screw coil will be the louder of the two, making
the volume drop less drastic when switching to
coil cut. My
L.P. clone was wired from the factory for the
screw coils to be active during coil cut and I've
decided to leave it that way, but it would be fun
to try it the other way to see how it sounds...
It would be cool to make the screw coil active on the neck pickup and the slug coil to be active on the bridge pickup, although I wonder if there might be an issue with the phase in the center switch position. I'm not sure.
20. Coil Cut Pot:
Instead of or in addition to a coil cut switch, you can put a volume knob in series onto the coil cut ground. That way, you can partially dial in the second coil. I think this is a brilliant idea. I love it. I would do it if I had a spare pot available. But I don’t, and I don't want to drill more holes to add one.
21. Series/Parallel wiring within each pickup:
There are two entirely different things people mean when they say the words “series” and “parallel” pickup wiring. The first is where each individual pickup is wired so that the screw and slug coils are switched to be either in series or in parallel with each other (stock is series). The other is where the two pickups are wired so that the neck and bridge pickups are switched to be either in series or in parallel with each other (stock is parallel). The first is discussed here; the second is discussed Section 23, below.
Normally each of the two
coils in a single humbucker pickup are wired in
means the electrical signal goes through one coil
in one direction and then back through the other
coil in the other direction, such that the ground
and out wires are both on the same side of the
can wire up a switch that can to change them to
means you connect both coils together on both
ends, so that the electricity goes through both at
the same time, from one side to the other, such
that the ground wire is on one side and out is on
With parallel, the sound is much brighter
and thinner, sort of like coil cut. One
advantage of parallel over coil cut is that
parallel retains some of the RF noise rejection of
the humbucker dual coil design, whereas coil cut
is just like a Fender… noisy.
Some people claim that parallel wiring can be really good sounding, with “more twang” than coil cut, and that Jimmy Page used it a lot. They say parallel wiring is especially useful if you have hot pickups because you can go from loud and fatter to quieter and airier.
Another disadvantage with individual pickup series/parallel switching is that the wiring is very complicated, and each DPDT switch can only do one pickup. So you need two DPDT switches (one for each pickup) to do parallel/series switching in both pickups. If you have only two switches like I do because you’re using the Bourns Premium audio taper pots with the conductive polymer element for volume, then the series/parallel switching it will take both of the tone knob switches and you won't have any switches for any other purpose.
I personally like the sound of coil cut, which takes only one switch, so I don't bother with within-pickup parallel switching.
22. Humbucker Treble Bypass:
I found this in a YouTube video: In a normally wired (in series) humbucker pickup, you can add a .005uf capacitor in parallel with whichever coil is second in the series (the one that goes to the volume knob, which in most guitars is the slug coil). This would be done by soldering one end of the capacitor to the junction of the two coil wires that are wired together, and the other end to the input terminal of the volume pot.
This is a particularly useful modification on a guitar that has too muddy of a sound on the neck pickup. It keeps the fat humbucker bottom end and most of the noise rejection, but it lets some high frequencies through to brighten up the tone. If it brightens up too much, an inline resistor can be inserted to reduce the effect. You can experiment with different values of capacitors to change the frequencies that are passed through, and you can also experiment with various values of resistors to change the amount of the effect. Or you can use a volume pot to make it adjustable.
The theory of how this works is it lets the high frequencies from the first coil bypass the second coil, thus avoiding the blocking of the high frequencies from the first coil by the inductance of the second coil. But the low frequencies are not affected so they sound the same as they did before.
The guy on the video called this “the best of both worlds” between series and parallel, and he says it sounds good with distortion. It seems like a great idea to me. You end up with the tight bottom end of a humbucker with the high frequencies of a single coil. I haven’t done this personally because lowering and tipping the pickup took care of the “dark neck pickup” problem to my satisfaction.
23. Series/Parallel wiring between pickups:
The stock Les Paul wiring puts the two pickups in parallel with each other when the pickup selector toggle switch is in the middle position. The Jimmy Page wiring allows the option to switch between parallel and series. Putting the two pickups into series makes a very dark, fat sound. From what I’ve read and heard, most people who have tried it say that the series sound is not very useable because it is too dull.
This mod takes one DPDT switch. Since I only have two switches, and one is already taken for coil cut, I decided that phase reverse is more useful than series/parallel wiring between pickups.
24. Phase Reverse:
This mod (also from Jimmy Page) allows you to reverse the phase of one or the other pickup, in order to place the two pickups out of phase with each other when the pickup selector toggle switch is in the center position. This gives a “scooped” sound. (The phase reverse has no effect when the pickup selector switch is in the Rhythm or Treble positions.)
This mod takes one DPDT switch. I have opted to use my second switch for this purpose. I don’t use it often, but it does make an interesting sound and I use it once in a while.
25. Master Treble and Bass Roll Off:
Below is a schematic for a master treble cut control and a master bass cut control that use the stock 500K pots and one of the stock .022uf capacitors, plus one .0022uf cap and a 1meg resistor. I think it’s an intriguing idea. It would be sort of like the treble and bass knobs on my basses. It doesn’t matter what pickup or pickups you’re using, there’s one treble knob and one bass knob for the entire instrument (instead of one treble knob for each pickup and no bass knob). A variation of this wiring diagram could make the treble roll off only for the bridge pickup and the bass roll off only for the neck pickup.
There are some obvious advantages to having a single treble roll off and also a bass roll off. This would give the most flexibility to instantly change tone no matter where the pickup selector switch is and no matter where the two volume knobs are set.
On the other hand, you might
lose the inductance effect (midrange boost) from the
orange drop capacitor in the treble roll off circuit that
was discussed above. Also, it might mess up what you can
do in phase reverse mode.
Another option would be to have the stock treble roll off on the bridge pickup and a variable Humbucker Treble Bypass (treble add – see 24 above) on the neck pickup.
So far, I’m happy with just lowering the neck pickup and leaving the tone circuits stock.
Overall Wiring Summary:
Here’s a diagram using three switches (coil tap, phase, and parallel). I used this schematic for the coil tap and phase, but I did not do the series/parallel:
Here’s the Jimmy page schematic (same as above but with separate coil cut switches for each pickup):
Recommended Maintenance Products:
Dunlop 65 String Cleaner and Conditioner on the strings. This stuff is great. It cleans off gunk and strings feel silky after application.