Όταν αλλάζεις πάχος χορδών επηρεάζεται και το intonation όπως πολύ σωστά είπε και yameth.Οταν απο 011 βάζεις 010 χωρίς να πειράξεις τίποτα τότε οι χορδες μπαίνουν πιο βαθιά στα slots του nut με διαφορα ανεπιθύμητα αποτελέσματα όπως τρίξιμο κλπ.Το πάνω μέρος του nut πρέπει ίσα ισα να καλύβει το πάνω μέρος της χορδής όσον αφορά τις 3 κάτω χορδές, για τις 3 πάνω E-A-D η χορδή θα πρεπει σταδιακά να πατά ολο και πιό λίγο στο nut.Δηλαδή η Ε η μπάσα να πατάει τα 2/3 στο nut. Και για να τελιώνουμε με το θέμα.Το intonation στις ακουστικές επηρεάζεται απο το action. Οσο ανεβάζεις το action τόσο πιο sharp γίνεται το intonation.Xαμήλωσε ή ανέβασε λίγο το action στο nut ανάλογα με το πρόβλημα που έχεις.Καλή Ανάγνωση.
Adjusting String Height
It is important to have the instruments saddle height and truss rod set properly prior to cutting the string depth in the nut. Cutting a slot too deeply will place the string against the first fret and result in buzzing.
A good indication that the nut slots are cut/worn too low is strings that buzz only when played open (un-fretted).
Slot Depth
The depth of the slots in the nut determine how closely the string comes to the frets, particularly the first fret. It is critical that the string have ample room to vibrate without contacting the first fret or you'll have an annoying open string buzz.
Adversely, nut slots that have not been cut properly can leave the strings higher than necessary above the first fret. This creates discomfort and higher action. A minor adjustment (say .020) can make a very noticeable difference.
High action at the nut also sharpens intonation.
Slot Width
Each string slot should just slightly exceed the diameter of it's string. If the slot is smaller than the string it may bind and create tuning problems. (And that annoying pinging sound when tuning up.)
If you've ever had to lift a string from a nut slot when changing strings it's a sure sign the slot is too small.
When changing string gauges, an increase in string diameter sometimes require an adjustment to the slots width.
Slot Angle
The slots must also be angled correctly. If the angle is too steep the string may actually rest on just a small portion of the slot causing premature wear as it is sitting on a small peak.
On instruments with minimal peghead angle the angle is especially critical for a clear, clean sound. A poorly angled nut slot can create a buzz like sound that can often be silenced if downward pressure is applied to the string behind the nut (over the peghead). This is often a sign that the string is not contacting the nut slot properly. The sound very closely mimics the sound of the string hitting the first fret when the slot is too deep.
Nut Height/Final Shape
Once the slots have been deepened I may remove material from the top of the nut, if need be, to avoid having the strings deeply buried in the nut. I want the slots deep enough to keep the strings from popping out when plucked but not so deep that they're buried.
Raising Action at the Nut
There are good reason's to salvage an original nut if possible. First of all vintage instruments often have lovely ivory and ebony nuts that are just too nice to scrap.
And of course, it is cheaper, especially if you have an instrument for which no pre-made plastic nut is available. Making a bone nut for a $100 guitar would not make much sense.
My method of raising the nut is to laminate matching material to the bottom of the nut. I use the term laminate and not shim because it is glued to the nut and can only be removed by sanding.
How about filling low slots and re-cutting? Superglue and baking powder have been used to fill nut slots that have been cut too low. I do not like the tone I hear from this method and prefer to raise the nut as a whole and re-cut.
Shims are placed beneath the nut and are often destroyed if the nut is ever removed again. I have seen the made from wood veneer, paper even pieces of credit cards. In my opinion, they look awful. When laminating material to the base of the nut it becomes permanent and more difficult to see. The nut can then be removed just as any other without having to make a new shim.
Securing a Loose Guitar Nut
If a nut pops loose I recommend using a couple of drops Elmer's or wood glue to reattach it. The use of permanent adhesives can create problems should the nut need to be removed for future repairs.
A small dab between the end of the fingerboard and the nut will do the trick and permit easy removal that does not damage the bottom of the slot when removing.
Lubricating Nut Slots
graphitall
On occasion it is helpful to lubricate the nut slot to reduce friction, binding and pinging. Because acoustic guitar usually have light colored nuts, using white graphite is often preferred to pencil lead graphite.
Acoustic Guitar Repairs
Action / Set Up
Binding
Braces
Bridge
Bridge Plate
Bridge Pins
Buzzing - Noise
Care / Maintenance
Cleaning
Convert Rt. to Lt.
Cracks
Fingerboard
Finish
Fret Replacement
Fret Types
Glue
Intonation
Neck Damage / Issues
Neck Angle
Neck Resets
Nut
Part Glossary
Pickguard
Pickups
Saddle
Strap Buttons
String Changing
String Choices / Effects
Truss Rod
Tuning Machines
Tuning Troubles
Guitar Nuts: The Basics
Nut Width/Length
Nut width is measured from the outer edges of the nut itself. Slight adjustments are normally necessary to insure a new nut fits flush against the sides of the neck.
E to E Spacing
The space between the bass E string slot and the treble E string slot will indicate how closely the strings will lay to the edge of the fingerboard.
Too close and the string may fall off of the edge of the fingerboard.
Too far and finger space may feel crowded when making chords.
While there is a small margin of adjustment, the E to E spacing must be correct to insure the strings have a proper distance from the edge of the fingerboard.
Common Nut Materials
Bone / Ivory
Bone nuts are dense, durable and often add sustain and clarity. All bone and ivory nuts are carved from scratch to fit the instrument in hand.
Tusq®
Tusq® is the brand name of a man made material quickly gaining in popularity. Tusq® nuts and saddles are used by Taylor®,
Gibson®, Tacoma® and many other manufacturers. These would be my recommendation for those seeking a ready made replacement nut.
Graphite
Graphite nuts are popular on electric guitars, especially those with tremolos. They help prevent string binding and provide a slick surface for the string to slide on.
Plastic Nuts
While these are standard on many factory instruments it should be said that there is a vast difference amongst plastics. Hollow, soft or spongy plastic nuts are sure to be a sustain and tone killer!
Corian®
Corian often has a very bright white appearance and is used on nearly all Martin® guitars. Corian is non-porous and dense make it a good choice for nuts.
Brass/ Aluminium
These use to be very popular but have lost the appeal, they are known for their brightness.
Ebony / Wood
You will find ebony on certain vintage instruments as well as many ukuleles.
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