StringsReunited.com

2. Intonation

This tip section is to help achieve a basic understanding of intonation and apply that to standard electric guitars. Acoustics, floating bridges and classical guitars will be covered in a later chapter.

Before starting, read this through a couple of times to familiarize yourself with everything.

Things you will need:
1. Small steel rule 6" (150mm)
2. Tape measure or + 700mm steel rule.
3. Small brush
4. Allen keys / wrenches
5. Guitar tuner ( with needle display)
6. Feeler gauges.
7. Cup of tea.
8. Small flat and cross head screwdrivers.
9. Tray for small parts if dismantling bridge

In the simplest terms good intonation is the correct setting of string length between the top nut and the bridge/saddles to offset differences in pitch when the strings are fretted. These differences will sound unpleasant and out of tune often becoming worse the further up the neck you go. Needless to say, the aim is to have your guitar with all the strings in tune and producing accurate notes wherever they are played on the fingerboard.

The guitar and other fretted instruments work on an equal temperament. This is the mathematical placement of the frets so they are able to be placed in straight slots which get closer together the further you go up the neck, with the corresponding pitch half a step ahead each time. This is a compromise to allow a flexible and playable instrument that can be used for playing in different styles and in different keys. Without this system we would end up with heavy maths and some very weird frets! (this has been done but the resulting instrument is inflexible and only suitable for playing in one key at any given time!)

There are a number of different factors that can affect the intonation including.. string gauge, height of strings, string material and varying pressure applied whilst playing. These are grey areas which can only be resolved by fine setting each instrument to suit each individual player. This can be time consuming and frustrating. However, once you have set your intonation it will only require periodic attention and not be something you need to do too often - unless string gauges or the action are changed, or of course if you play in a particularly violent manner - in which case, intonation may be the last thing on your mind!

The tele is my favourite guitar so once again I will be using it to illustrate examples but the methods described can be applied to most guitars with adjustable bridges and saddles.

Even if you may have a digital or strobe tuner, find yourself a quiet area to work in as it will be almost impossible to achieve the best results if you are unable to hear the tone produced from the strings. Try and plan enough time for the whole job - an hour or so should do it - rather like piano tuning, hopefully you will find that you can shut everything out and focus down on what you are hearing and it becomes enjoyable in an odd way, and if you have any distraction, it may take a while to switch back in.

When setting the intonation it will make life easier if you are able to fit a new set of strings as they will give a clearer tone and help give more accurate results. If you don’t have a new set you will still be able to improve things but a new set is ideal.

If all the strings have been removed you can set the rough positions of the saddles before fitting the strings. If you have time and are going to the trouble of thoroughly sorting out your guitar, you may want to remove the saddles and clean everything up if you feel like it. If you don’t have time for all that, you can clean the saddle springs and screws off with an old tooth brush and then dust off the resulting mess of old skin and fluff with a nice small paint brush (before you dip it in the paint!). Be sure to lay all the saddles, screws and springs out in order as some of these may vary in size or thread position and be sure watch out for the springs flying off and under the table.

Once everything is all is nice and clean, reassemble each saddle, spring and screw so the bridge is complete.

The next step is to measure from the front edge of the nut to the centre of the twelfth fret and double it (which in this case is 647mm). This should be the distance from the front edge of the nut to the centre of the top E saddle where the string makes contact. Adjust the top E saddle until this measurement is exactly the same. The second saddle (B) should be set back from the first by an amount equal to the gauge of the string. If you are using a 10-46 this should be .35mm (it can be easier to just physically use each string as a guide for all as this is a rough setting). The third saddle (G) should be set back in the same way from the second (.43mm). The fourth saddle (D) should be set back so it is level with the second. The fifth (a) and sixth (e) strings should be set back in the same way (.91mm) and (1.16mm).

If you have an old style bridge which has adjustment on three pairs of saddles, set the top E as described, the following pair set back approx .7mm and the third pair approx 2mm, remember this is only a rough setting.

If you have a Gibson-style bridge don’t try and dismantle it unless absolutely necessary. If you do, be sure to take note of saddle orientation and clip.

When they are all set, have a break for a minute or two and drink the tea you ordered which may now be cold. Its worth having a think about the procedure you have just covered and understand why it needs to be done.

When you have fitted your new strings and stretched them in as described in the previous chapter, you are now ready to set the string height which should be done before setting the intonation as any changes to the height will upset it.

There are some things with guitars that have to be exact but within reason, one thing that is down to individual taste is the string height or ‘action’. This next section is a guide and you should continue until it feels right for you, just remembering that if the action is too high it may be very difficult to set the intonation correctly as the amount the string stretches when fretted directly affects the intonation.

Get your six inch (150mm) ruler – one with a matt finish is easier to read – and measure the distance from the bottom of the strings to the top of the 17th fret – a good starting point is approximately 2mm on the bass side and 1.7mm on the treble side. Adjust each saddle in turn until you get these measurements across all strings (you may have to keep re-tuning as you go). Once you have this set then adjust to suit yourself until it feels comfortable and produces a good tone.

The next part is the fine setting of the intonation which may need going over a few times, the initial setting can be done with the guitar laid on the bench but the final setting should be done whilst holding the guitar in playing position to achieve best results.

Using your tuner and your ears you now need to match the 12th fret harmonic with the fretted note. Starting with the top E and working down, play the harmonic at the 12th fret and tune exactly, then depress the string at the 12th fret and play the note again, be careful not to press too hard or push it sharp one way or the other. If it reads sharp you will need to adjust the saddle backwards, de-tune slightly and move the saddle back then re-tune and repeat. You may need to do this a few times until the harmonic and the fretted note are the same. If it reads flat the saddle will need to come forward. This will sometimes slide forward or may need a slight push if the spring is weak. Again re-tune and check, adjusting as necessary until even. Repeat this with all the strings remembering to keep all in tune as you go. This should now be repeated with the guitar in playing position. You may need to go over this a few times until all is well. Happy playing!

Tech tip 3 will be Tremolo setup.