Hey welcome back Groovy Guys and Gals. In last month’s issue we went through a few Factory Specs, how to set your neck relief and how to adjust string height on your guitar or bass in order to get it back to the way it was when it left the factory. In this month’s issue we will go over intonation, pickup height adjustment and checking the nut height before we tear those old strings still off.
In the dictionary it says “Intonation, in music is a musician’s realization of pitch accuracy, or the pitch accuracy of a musical instrument. Intonation may be flat, sharp, or both, successively or simultaneously”. In other words it’s all about how accurately your Axe is when you tune it.Because of the nature of a guitars scale and the placement of the frets each string needs to be an exact length for it to be in tune from the first fret to the last. The majority of guitars are based on either a 25 ½” (Most Fender guitars) or a 24” (Gibson guitars) scale. The most popular scale for bass guitars is 34” The scale is the part of the string that vibrates or the measured distance from the nut to the bridge. Intonation can be affected by many things, the gauge of your strings, how old your strings are, the height of your strings, changes in temperature and humidity (we are talking about something that is made of wood you know!) and on and on. Let’s just say it is a good practice to check the intonation on your Axe on a regular basis. As a minimum at least every time you change your strings. Most electric guitars and basses have adjustable bridge saddles for the very reason of adjusting the length of the string and in turn “fine Tuning” the intonation of each string.
One thing to remember, to properly intonate a guitar or bass you should “always use new strings”. So now you are asking yourself why is he making me use these old dead strings to intonate my Axe? He just said always use new strings! The answer to this is because I’m a cheap bastard. We are going to use the old ones here to get as close to the final saddle location that we can. This helps to minimize bends in the strings over the bridge when you do the final set up of your Axe with new strings and in the end could save you a set of strings. Remember bends or brakes in a string cause a weak spot where the string can break when you are playing hard.
So to do your intonation you will need an electronic tuner and a flat surface to lay your Axe on. Always use an old towel, old piece of carpet or something on your work surface to lay your Axe on and save the scratches for someone that likes to Relic guitars. Plug in your tuner and tune your axe to pitch. It is important to tune it as close to dead on as you can. Remember always do one string at a time. Once the string is tuned to pitch play the harmonic on the same string at the twelfth fret and make sure the pitch is still dead on. Now, fret the string at the twelfth fret by placing your finger tip on the string directly over the fret. Do not press too strongly you only need enough pressure to get a clear note off of the twelfth fret. If you press too hard you will cause the string pitch to go sharp. When I do this I typically will use my finger nail to hold the string on the fret.
When you play the note at the twelfth fret hold the string down directly over the crown of the fret and do not apply to much pressure. Just enough pressure to get a clean note.
Now with the string on the twelfth fret gently pluck the string and see if the note played is sharp or flat. If the note is flat it means you need to move the saddle towards the nut. In other words, you need to shorten the length of the string. If the fretted note is sharp, you need to move the saddle away from the nut, you guessed it, you need to make the string length longer. Adjusting the saddle is done with either a screw driver or an Allen wrench. Fender style guitars typically adjusted at the bridge plate or the tremolo. Gibson style guitars are adjusted at the bridge piece.
Remember ½ turns on the saddle adjusting screws and then recheck the intonation.
Gibson and other ABR style Tune-O-Matic bridges are adjusted using the screw on the front of the bridge piece.
Always turn the adjusting screw a half turn at a time; it doesn’t take a lot of saddle movement to make a big change to the intonation. When adjusting a saddle away from the nut you may want to loosen the string a bit to reduce the tension caused by the string. Once you have moved the saddle, re-tune the string to pitch and repeat the process until the pitch of the harmonic and the pitch of the string played at the twelfth fret are both in tune, it may take a few attempts to get it right but stick with it. It makes all the difference in the world when your notes and chords are dead on all the way up the neck. Once the first string is done, repeat the same process on the rest of the strings until they are all done.
A little note to all you Floyd Rose users out there. Intonating a Floyd can be a pain in the ass because you need to first unlock the saddle Allen screw that locks the saddle in place. When you do this with the string under tension, it will slide forward towards the nut causing the string to go flat. If you plan to intonate your Floyd on a regular basis, invest in a little tool sold by many Luthier suppliers. The tool holds the saddle from moving when the locking screw is loosened. It also has a screw that is turned to allow you to adjust the location of the saddle accurately and then lock it down. The overall process of intonating an Axe with a Floyd Rose is the same as above. The tool just reduces the amount of swearing you will do without it.
The special tool shown above is for adjusting a Floyd Rose tremolo. It hooks on the end of the bridge and the fine tuning Allen screw to allow easy intonation of Floyd Rose type saddles.
When you adjust the height of your pick-ups, keep in mind that a bass E string is always louder than a Treble E string. It also vibrates in a larger elliptical pattern than the other strings because of it’s low tuning and it’s gauge. So when we set pick-up heights, we typically will set the height under the bass E string lower than the height we would use on the treble E string. In last month’s issue I gave you the factory heights to set your pick-ups at. The dimensions given in the table are the height from the top of the pole piece or screw to the underside of the string for a given pick-up. Keep in mind all measurements should be taken with the string held down at the last fret on your neck. To adjust the pick-ups use a screw driver to raise or lower the pickup to the required height. Turn the screw clockwise to raise the pick-up and counter clockwise to lower it.
The above photo shows the Pickup adjusting screw on a Fender style guitar. Turn the screw clockwise to raise the pickup height and counterclockwise to lower it.
When checking your pickup height it is always the distance from the top of the pole piece to the underside of the string. Make sure you are holding the string down at the last fret when you take your measurement.
The photo above shows the adjusting screw on a Gibson Style pickup holding ring.
Again here, always measure from the top of the pole screw to the underside of the string.
The photo above shows the difference in height from the treble E string to the Bass E string.
Typically after adjusting the height on a set of pick-up’s I will plug in the guitar or bass and check the volume of each pick-up. The closer the pick-up is to the string the louder it will be. I will normally set the treble (Lead) pick-up a little closer to the strings then the rhythm pick-up just to give it a bit more bight. It really is a thing of personal preference, so try a couple of different heights until you find one you like.
Checking Your Nut Height
When talking about checking the nut height on a guitar or bass we are talking about the height of the string from the top of the first fret to the underside of the string or the height of the strings off the top of the fretboard. This height relates directly to how deep the string slots are in the nut. If the string slots have been cut too deep in the nut the strings will be to low to the fretboard and will buzz. If the string slots are cut too shallow the strings will be too high off the fretboard and will make the guitar or bass harder to play. To check your nut height take a set of feeler gauges and select the factory dimension given it the table from last month’s issue. Then slide the feeler gauge along the top of the first fret and check to see if it makes contact with the underside of the string. If it space is larger or smaller than the info given in the factory specs adjust the size of the feeler gauge until you find the correct height. The gauge just needs to touch the underside of the string, not raise it. If your Axe meets the factory specs cool. If not write the measurement down so you have a record of the height. If the string is too high you will need to file the string slot in the nut deeper to adjust the height. If the string height is too low you will need to replace the nut with a new one.
A word of warning: The nut on a guitar or bass is probably one of the hardest things to get right on an Axe. If you do not feel comfortable with playing around with it or, don’t mind having to spend some money to fix any mistakes you might make, leave the work to a professional. I will be doing a column on how to install, setup and file nuts in a future segment. So stay tuned.
In the above photo I am using a .018” feeler gauge to check the nut height the string height above the first fret.
Remember you are looking for an accurate dimension when checking the nut height, that’s why we measure in thousands of an inch. Insert the feeler gauge so it rest on the top of the fret and just touches the bottom of the string.
So that’s it for this month. Next month we’ll talk about a few tricks that you can do to get a vintage style six screw tremolo to stay in tune. If you get a chance please visit my web site at www.readcustomguitars.com. Also if there are any questions please send them along to www.loudguitars.com and I will do my best to answer them in a timely manner.
Cheers and remember
Stevie Ray Vaughn
To read more about Mark click HERE