Summary: What is intonation?

Intonation is basically scale length compensation. The guitar is an unevenly tuned instrument (unlike a piano for example which is perfect) which means that as you play across the fretboard some notes are slightly flat and some are slightly flat. To adjust this, and get the whole guitar as in tune as possible, we adjust the saddles on the bridge which shortens or lengthen the scale length (length of the string from the nut to the bridge).

In terms of when you should adjust the intonation, it is very much the last thing you do in your set up. It is the only process that won't have a knock on effect, and therefore we do it last. Once your neck relief and action is sorted, only then do you adjust the intonation.

Summary: Before you start

Just before you start adjusting your intonation, be sure you have completed all the other set up processes and have a good tuner ready to go! The more accurate you can get the open string tuning, the more accurate the intonation will be. Also, we tune up on the bench for the demonstration purpose, but you should use the playing position to get an even more accurate intonation. Be sure to also use the same level of attack every time you pluck a string. This ensures you get even notes. As a final point, on a Strat style guitar, the adjustment of the saddles for intonation takes place at the back of the bridge, as shown here:

Checklist: Adjusting intonation

It's time to put some theory into practice and adjust the intonation. Here is a handy checklist to help you stay on track as you intonate your guitars.

• 1. Get the open tuning perfectly in pitch, ideally in the playing position
• 2. We start on the low E string, where you need to fret the 12th fret and pluck the string
• 3. Check the tuning, is it sharp, flat or perfect?
• 4. Adjust the saddle at the back of the bridge using a screwdriver. Tighten the screw if the string is sharp, and loosen it if the string is flat
• 5. Retune the open string
• 6. Re-fret the 12th fret and you should see the note is now closer in tune. If you need to make any further adjustments then runt he process again in the E string
• 7. Once you are happy with the E string, repeat the whole process for all 6 strings

Summary: Different Bridge

We chose a Gibson style guitar for our second demonstration because of the different style of bridge. Gibsons typically have either Tune-o-matic or ABR bridges. Both are very similar and are adjusted differently to the saddled bridges on Fender guitars. These kind of bridges usually require a flathead screwdriver rather than the phillips. The picture below shows you how you would adjust these kind of bridges.

Checklist: Adjusting intonation

It's time to put some theory into practice and adjust the intonation. Here is a handy checklist to help you stay on track as you intonate your guitars.

• 1. Get the open tuning perfectly in pitch, ideally in the playing position
• 2. We start on the low E string, where you need to fret the 12th fret and pluck the string
• 3. Check the tuning, is is sharp, flat or perfect?
• 4. Adjust the saddle on the bridge using the flathead screwdriver. Tighten the screw if the string is sharp, and loosen it if the string is flat
• 5. Retune the open string
• 6. Re-fret the 12th fret and you should see the note is now closer in tune. If you need to make any further adjustments then runt he process again in the E string
• 7. Once you are happy with the E string, repeat the whole process for all 6 strings