Guitar Repair FAQ

What is a “Set Up” and do I need one?

One of the more common jobs we do is what is called a “set up”.   In this video, guitar maestro Michael Fix askes just that question and comes to visit us for the answer.  We also explain things on this page below.

Michael Fix visits Armstrong Lutherie to Discuss Guitar Set-up with Andrew Armstrong

What is a “Set Up” and do I need one?

Getting your guitar “Set Up” means is making usually fine adjustments to the guitar to achieve the best playability while making sure the guitar plays in tune and buzz free.  A set up normally entails checking that the neck is appropriately flat (not bowed), the frets are level and in good shape, the string height (known as ‘action’) at the 1st fret and 12th fret is optimised for playability and buzz-free playing, the string compensation (see below) is optimised so the guitar plays in tune along the neck and check that any onboard electronics are working properly.  In addition to this, we will clean and oil the fretboard, give the guitar a general clean up, inspect it to make sure there aren’t any other problems lurking out of sight and if applicable that strap button screws and other hardware are tight and working properly.  How this is done varies from guitar to guitar and especially between acoustic and electric guitars and basses.

Do I need one?

Unless you’ve had your guitar professionally set up recently or you’re very lucky, it is most likely that your guitar will benefit from a good set-up.  Even new guitars straight out of the shop benefit greatly from being professionally set up.  Factories almost never do final set-ups and leave it to the shop staff or a third party luthier like Armstrong Lutherie.  If you’re lucky, the shop where you bought your guitar may have done a set-up before it leaves, but don’t count on it.

What is ‘string compensation’?

There is a very long-winded technical answer to this question but suffice to say that guitars are inherently imperfect when it comes to playing in tune.  The act of playing a note on the fretboard requires the string to be pressed to the fretboard and that stretches the string a little, pulling it out of tune.  This varies up and down the neck and, in addition, the fret spacing used is a compromise to enable a guitar to play reasonably in tune in all keys.  While it is very challenging to get a “perfectly” in-tune and playable guitar, we can achieve an acceptable result by adding a small amount of extra length to the strings beyond Scale Length (see below).  This additional length is called ‘compensation’ because it compensates for the little stretch made when fretting a note.

How much compensation is required?

In simple terms the stiffer a string the more compensation is required.  Have a look at your guitar and if it has steel strings you will see that the saddle is set further back on the bass strings compared to the treble strings.  This is how it should be!  For a nylon-string guitar with very flexible strings, the amount of compensation required is much less and varies little from string to string, so the saddle is usually perpendicular to the strings.  This is how it should be!

What is ‘intonation’ and is it different from ‘compensation’?

Intonation is closely related to compensation – some people use the two terms interchangeably.  When we talk about checking the intonation we are checking whether the string compensation is correct.  Again there is a lot more to it but in simple terms, we check that the note played at the 12th fret is in tune (i.e. exactly 1 octave higher than the open string note) and if it is, it is intonated correctly.  Otherwise, the intonation is out and the string compensation needs adjustment.

What is Scale Length?

One of the most important dimensions of any guitar is its scale length.  This is the theoretical length of the string from nut to saddle.  It is used to calculate the exact position of each fret so that the guitar plays in tune.  Scale length (SL) affects the amount of tension in the strings for a given pitch and therefore the tone of the guitar and the feel of the strings.  Longer string length means more tension, brighter tone and slightly harder feel under the fingers.  This is the main reason Fender guitars with a SL of 25.5” generally sound brighter than a Gibson with SL of 24.75”.  Scale length is not adjustable … unless you‘re prepared to relocate every fret and the bridge/saddle.

For a summary of common scale lengths, check out this page from Stewart MacDonald.

What is a truss rod and what is it used for?

The truss rod is an adjustable steel rod (or pair of rods) embedded in the neck to enable any bowing caused by string tension and environmental changes to be addressed.  Depending on your guitar the truss rod may be adjustable at the headstock (most electric guitars) or through the sound hole (acoustic guitars).  Most modern guitars have a two-way truss rod so that the neck can be adjusted for both up-bow and back-bow.  Older guitars generally have a one-way truss rod that can only adjust up-bow.

Another important point to make is that the truss rod is NOT for adjusting action (string height).  Yes, if you adjust the truss rod it will affect the action but that is not it’s primary purpose and should not be used to adjust action except in subtle cases where environmental factors can cause minor changes to neck geometry and therefore action.

Should I adjust my truss rod?

We strongly suggest you leave truss rod adjustment to an expert.  Truss rods can be broken or damaged if over tightened leading to repair costs that are generally more than the guitar is worth.

My frets are looking a bit worn with small groves, can these be repaired or do I need new frets?

This question mostly arises in relation to steel string guitars.  The frets on steel string guitars get worn in the areas where they are played the most.  This causes flattened tops and/or small groves or divots in the frets.  A guitar can play perfectly well for a while with this wear but eventually, it needs to be addressed.  We can usually ‘dress’ the frets to remove divots and irregularities and re-crown them to bring back to original shape.  They will be a little lower however so action may also need to be adjusted.  It is important to dress all of the frets so as to not have uneven frets.  Eventually, after a couple of fret dressings, they will need to be replaced – either a full or partial re-fret.

Should I consider stainless steel frets or some other fancy fret wire?

Good question but not one that we’ll attempt to answer here.  We offer regular nickel/silver fret wire, Evo-Gold fret wire (which is of intermediate hardness) and stainless fret wire which is the hardest and longest wearing.  Come and chat to us about your playing and fret wire requirements.

My electric guitar is making some unpleasant sounds – hums, rattles, pops.  What’s up with that?

There are numerous things that lead to unpleasant noises emanating from an electric guitar.  These include:

  • Damaged wiring
  • Dirty control pots (Volume & Tone controls) and switches
  • Badly earthed components
  • Dirty/dodgy output jacks
  • Lack of shielding from electrical interference.

All of these can be addressed in our workshop.

What can I do to change the tone of my electric guitar?

This is not a question that can be answered in this set of FAQs.  Tone can be affected by many components of the guitar including the choice of pick-ups, how they are wired and combined through switching, passive vs active electronic circuits, choice of tone capacitors and installation of treble bleed circuits.  The list goes on.  If you are interested in this topic get in touch and we can discuss options to get the result you’re after.

What can I do to change the tone of my acoustic guitar?

Again there are many factors that affect the tone of an acoustic guitar but there are fewer options available than with an electric guitar.  If your guitar has a plastic nut and saddle consider swapping them for bone or another quality material such as TUSQ/Nubone.  Getting your guitar properly set-up will also have an effect.  However one of the best things is to change your strings!  Try some other metallurgy (e.g. bronze, phosphor bronze, 80/20 bronze, Monel, etc) coated or uncoated.  And consider playing on a heavier gauge string if you’re currently playing on extra or custom light strings.  They will generally sound louder and have better tone and your fingers will get used to them soon enough.