Troubleshooting guitar tuning problems

There are several reasons why a guitar may appear to have tuning problems. Most people are quick to assume that the machine heads (tuners) are the reason for a frequently out-of-tune guitar, but in fact they are rarely the cause.

Here are a few causes, how to spot them and very briefly what to do about them. I’ve listed these more or less in order of cheapest/easiest to most expensive/difficult to repair. Some of these have been covered in more detail in previous posts, and others will be covered in future posts. I’ve left out tremolo problems because I’d like to do a separate article about those.

Strings are still "settling in"

When you first put new strings on a guitar, they are very springy and take a while to settle in, Settling in really means stretching. You can speed up this process by manually stretching the strings after you put them on your guitar. Simply put your finger under each string (about halfway up the neck is fine) and pull the string away from the guitar by a few inches. Don't pull so hard that you're in danger of snapping the string, though. You'll probably have to re-tune the string after doing this, but this only shows that you have most likely successfully stretched it.

Guitar intonation is wrong

Guitar intonation refers to how well the neck length and the fret spacing match up. That might sound very technical, but the only thing a normal user probably needs to worry about is the forward/backward position of the saddles. If you suspect your tuning problems are caused by an intonation issue, try the following. Tune the open strings properly and then check the same strings at the 12th position. If they are in tune (exactly one octave higher), then the intonation is probably OK. If not, then this can be fixed by adjusting each saddle until open and 12th positions of each string match up (exactly one octave apart). Note: If the 12th fret note is too high, move the saddle back. If it’s too low, then move the saddle forward.

Guitar action is too high

If the strings are too high off the fretboard, either because of a bowed neck or saddles that are set too high, then in certain positions, especially higher up the fretboard, the strings have to be pushed down so far to meet the frets, that you end up stretching them. This will, unsurprisingly, knock them out of tune. In some ways, the tuning problems are the same as when the intonation is wrong, in that the higher up the fretboard you go, the more the strings will be out of tune. The difference here is that you will know the strings are too high because you have to exert so much effort pushing them down to the frets.

Guitar action is too low

If the strings are too low, you’ll know pretty quickly, as the strings will rattle against the frets. The easy fix for this is to set the action a bit higher until the buzzing stops. If you find that you need to set the strings very high to avoid this, then you may need to look at the neck bow. You might also want to think about other reasons for rattling noises, such as the problem emanating from the nut or the saddles.

Nut is too high

A nut that is too high gives you similar problems to when you have guitar action that is too high, except that the out-of-tuneness is most noticeable in the lower frets, as the string is really having to be pushed down a lot more in those positions. If the string height over the 1st fret seems far too high, then maybe consider lowering the nut, or one of the slots if a particular string is affected.

Nut is too low

A nut that is too low is going to give you similar rattling problems to when your guitar’s action is too low, except that it ONLY affects the open string. If you are getting a rattling sound and suspect the nut may be the problem, put a capo on the first fret and see if the problem disappears. If it does, then the most likely problem is the nut. In fact, this is a great way to diagnose ANY nut problems.

Nut is pinching strings

Sometimes the guitar nut pinches the strings (i.e. grips them too hard) because the nut slots are filed too thin for the strings you are using. You will know if this is the case because when you turn the machine head, the string will make a pinging sound as it jumps up or down in pitch while being tuned. This jumping makes tuning difficult because you cannot really fine tune (not to mention the additional problems you will encounter if using a tremolo – but that’s for another day). The solution here is to widen the string slot on the nut (be careful just to widen it and not to lower it).

Nut slot is angled badly

The nut slots should be angled slightly so that the highest point in the slot is just where it meets the fretboard. You could probably just about get away with a perfectly horizontal slot, but I really wouldn’t recommend it. A slot which has its highest point nearer to the head of the guitar, or anywhere else between the front and the back is absolutely unacceptable, as this is, in effect, moving the position of the “zero” fret. Think of it like having a bridge saddle too far back or forwards, but at the other end of the guitar.

Strings are not wound onto machine heads (tuners) properly

Strings that are not wound correctly are subject to slippage or other issues. There are many methods to wind a string, but I personally prefer this method: http://diystrat.blogspot.com/2011/08/stringing-guitar.html

Machine heads (tuners) are bad

Machine heads fail for a number of reasons. Sometimes they’re just not very precisely made, sometimes things wear out, or sometimes things break. However, machine heads are not the cause of tuning problems as often as you might think. If you are pretty sure one of your machine heads is being problematic, and you want to test it before paying for a new one, try swapping its position with another machine head on your guitar. Now pay attention to where the problem is. Did it stay with the string or with the machine head? If it stayed with the machine head, then, OK, feel free to buy a new one.

Uneven frets (high/low fret)

I’ve left this one to the end because, in my opinion, it’s the one you’re most likely to have to pay a guitar tech to fix. An uneven fret is a fret that sits too high or too low on your fretboard. If it’s too high then when you play one fret closer to the head of the guitar, the string will actually hit this fret instead. If it is too low, then when you play this fret, it will hit against the next fret towards the bridge of the guitar. A higher fret is easier to fix, but for both I would recommend just taking the guitar to a professional. There is one workaround you might consider, though. If the uneven fret is not VERY high or low, increasing the action of the guitar a little may make it not noticeable enough to be a problem.


Well, I hope the above information has been of some use to you. I’ve tried not to go into too much detail because it’s a lot to take in already, and, frankly, you could write a book about this stuff (as some have). As always, if you have any questions or anything else to say, please feel free to leave a comment below.

Making a (bone) nut from scratch

I’ve made a post on here before about making a nut (out of ebony) by tracing an outline around the old nut (http://diystrat.blogspot.com/2009/06/making-ebony-nut-and-saddle.html), but today I’d like to show you how to make a nut for an acoustic (or electric) guitar from scratch. This is for a couple of reasons:

1. The old nut might be missing or damaged.
2. You may not be able to trust or may not be happy with the shape of the previous nut.

So let’s look at the patient first. Here’s an acoustic guitar missing its nut. Just a quick note here... there are some remnants of glue in the slot and that should be removed with a sharp knife before proceeding further.

Assuming you have now cleared out all the glue, and are ready to start making a nut, you will first need a blank. Here’s mine:

I was going to tell you that the first thing you need to do is thin the blank a little so that it will fit in the slot, but it turns out the blank I had was perfect already. If you DO need to thin it a little, check out the ebony nut post to see how I did it there. Oh, and if the blank is already TOO thin, then forget it – you need a new, fatter blank.

So far we have a blank that is the correct thickness, but not the right width.

Mark the edge(s) with a pencil and cut it down to size with a hacksaw (not while it's sitting on the guitar, as the photo might suggest).

The next step is to shape the blank nut to the same radius as the fretboard, and make sure the strings pass over it at a suitable height above the other frets. This is the step that you can miss out if you just trace the previous nut’s outline, and is also where a lot of people get stuck. However, it’s not hard at all.

You will need a very specialised tool for this next step, namely the “half pencil”.

Here’s a “whole pencil”. We need to split it down its middle.

First let’s remove that pesky eraser thing at the end. A pair of pliers will make short work of that.

A decent sharp strong knife is required now. I don’t recommend using a craft knife for this – it’s too brittle. Here’s the knife I used.

DISCLAIMER: If you don’t know how to use a knife safely, stop here. I will not be responsible for any injuries you might cause yourself.

If you look at the end of the pencil, you may be lucky enough to find where the two halves were stuck together originally (yes, that’s right, a pencil has two halves, plus the lead – they don’t just drill a hole through a long piece of wood and insert the lead that way).

Unfortunately for me, I couldn’t see the join, so I had to guess. My first attempt was a disaster.

Further detective work revealed a faint line down the sides, so I tried to follow that. Success!

The half pencil is pretty rough at this stage, not least because the lead itself will remain mostly intact. That’s fine.

What we need now is our trusty piece of sandpaper sitting on a nice flat piece of, well, pretty much anything hard (in my case a floor tile).

Sand the bottom of the pencil until you have a nice flat surface and you are now the proud owner of a half pencil!

You can see from the photo how much carbon has gone everywhere. It’s probably a good idea to wash your hands at this stage to prevent more unwanted carbon marks. Also, to stop the pencil lead from falling out (there’s really not much holding it in at this stage), I recommend running a length of Sellotape (Scotch tape) along the exposed part of the pencil to hold it all together.

Place the half pencil on the frets and pull it across the fretboard, while drawing a line on the nut (which you’ll need to hold in place for this part).

You will now have a line marked on the nut where, if you were to file down to this line, it would be exactly in line with the other frets.

In fact, you need to make a line a little higher than this. Some people would recommend freehanding it, but I prefer placing something under the pencil and drawing another line. A good safe distance is about 1-2 mm. I thought I had one of those wooden coffee stirrers lying around, but I couldn’t find it, so I used a lollypop stick.

You can tape this to the bottom of the pencil and draw another line to give you a good (safe) line to shape the nut to before you start filing the string slots.

Here’s the nut with the second line drawn:

And here it is filed down to that line:

Next thing to do is mark the position of the string slots. For this I have a nice little position chart. I got it with my nut files, but I’m sure you could find a printable one easily enough online.

Here are the nut files I’m using:

I use my nut files to file slots down to about halfway between the two lines (not quite finished in this picture).

Remember not to file the slots exactly level (horizontal), but rather at a bit of an angle, angled down towards the peghead side of the nut.

You’ll probably also want to shape the back of the nut so that it curves down a bit on the peghead side. This helps the strings to find their way to the machine heads without too much interference.

This next part isn’t entirely necessary, but if you want to make the nut nice and shiny, you can use something like these micro mesh pads from stewmac.com:

First use the roughest one (be careful not to alter the shape/thickness of the nut), then move through each pad until you get to the smoothest one. You’ll end up with a nice shiny nut. You could just as easily use different grades of sandpaper to do this job, or possibly some other sort of abrasive.

Here’s the finish I got after just a few minutes’ work with the micro mesh pads:

I’m sure an even better finish could be achieved with a little more effort.

So now it’s time to test the nut out on the guitar. DO NOT glue it in place at this stage.

As you can see the strings are sitting a bit high, but the good news is that we can simply file a bit of height off the BOTTOM of the nut now – no need to do all that shaping, slot filing and shining work all over again.

I mark the nut with my best guess for how much to take off (remember you can always take more off, but not really put it back), so better to take off a little at a time.

Another test fitting after removing some height and I’m happy with the results, though I’ll play with it for a while before deciding for sure.

Once you are sure you are happy with the nut, you can glue it in place (although this is not entirely necessary, as the strings will hold it in place very well – just be careful if you ever remove all the strings at the same time).

The question is which glue and how much to use. I’d recommend a very weak glue. Cheap white craft glue, even watered down about 50% is more than sufficient. A single drop near each end of the bottom of the nut is enough.

Finally, here is the happy patient, with its new bone nut, made from scratch. Please feel free to leave a message if you have any questions or comments.

Installing Graph Tech saddles on a Tune-O-Matic bridge

Removing and replacing the saddles on a Tune-O-Matic (TOM) bridge can be a confusing and somewhat fiddly process, but really isn’t that difficult. Note, though, that there have been several variations of the TOM bridge, and the process differs slightly from model to model. Also important to note is that each different bridge requires a different set of Graph Tech saddles, so make sure you buy the right ones.

Go here to check which model you need: http://www.graphtech.com/products.html?SubCategoryID=34

Here’s the patient. It’s a 1993 Gibson Les Paul Studio.

If you look closely, you can see that the strings have started to make their own slots where they shouldn’t, though that's not the only reason for this upgrade. The bridge in question is a Nashville pre-2000 bridge, which means the required Graph Tech saddles are part number PS-8500-00.

Once the strings are removed, the bridge lifts off very easily. In fact, be careful it doesn’t fall off when you aren’t paying attention (same goes for the tailpiece, which slides off back the way). Here’s the bridge, with the old saddles still in place.

It is important to understand that TOM saddles (or rather, their screws) are held in place with some sort of retainer, be it a spring, wire, clip, or whatever. Luckily, this particular model allows the saddles (and their retainers) to be removed very easily.

First, unscrew the screw holding the saddle in place. As the saddle hits the front of the bridge, you will feel some resistance, but if you (carefully) continue to unscrew, the screw will force its way past the retainer and start to exit the back of the bridge.

Looking under the bridge now, you will most likely still see the retainer sitting in place. If you don’t see it, then it’s time to look around as it probably fell on the floor or workbench.

The retainer can easily be lifted out with a screwdriver or similar.

Repeat this process for all six saddles.

It’s a good time to give the bridge a good clean at this stage, as it’s unlikely to be as easy to do so anytime soon.

Here’s the set of Graph Tech saddles.

The saddles also come with six retaining clips (small E Type circlips). Make sure you don’t miss these as they are hidden behind the sponge in the packaging.

The saddles are placed in the bridge as follows, and the screws screwed in without the clips. Note that three of the saddles have wide slots (for the wound strings) and three have narrow slots (for the unwound strings). Make sure you put these in the right positions.

Now for the fiddly bit, the clips have to be pushed onto the small grooves in the screws. The location of the grooves is pointed out below.

A fairly simple way to do this is to place them more or less in place with pliers and then push down quite hard with a blunt instrument – in my case, a blunt punch. You will feel a definite click into place when they move to the correct position. Again repeat this process for all six clips.

Here's the bridge with all six saddles and clips in place. The position of the saddles is a bit of a guess at this moment.

The bridge is now put back on the guitar and intonated accordingly (that lesson’s for another day).