Mammoth Ivory Nut install on a Gibson Les Paul 120th Anniversary Edition

I see lots of Gibsons in our workshop. They are very often great guitars with issues that really shouldn't be there! This particular guitar is a Gibson Les Paul 120th Anniversary made in 2014 and was brought in for setup.

Initial inspection:


  • 2.75mm action at the 12th fret Bass side 2.5mm Treble side
  • Truss Rod needs tightening
  • Intonation Needed
  • Possible Nut issue - Too low on 5th & 4th string

Nut Height Problems


In order to establish if there is a problem with nut height there is a quick method.

Place your finger at the 3rd fret and look at the gap between the string and 1st fret. There should be a small gap.

If there is no gap then it is possible the nut is too low. It is also important to be aware of any fret issues.

After I had adjusted the truss rod and checked for any fret issues I could see the nut was far too low on the D string in particular. With the truss rod adjusted correctly there was almost no resonance from the open string. I looked at the options for amending the problem and talked to the customer about a replacement for the nut. This would usually be a piece of bone, which I would carve from a blank, or a Graphtech / Tusq pre moulded replacement.

Mammoth Nut

Mammoth Ivory can vary hugely in colour from light cream through to almost chocolate colour streaks running through it. Having not worked with any other type of Ivory I don't know how particular colouration variance is to Mammoth. I don't imagine there is going to be any noticeable tonal difference from Bone but it certainly looks a little different. This particular blank is a beautiful aged (10,000 years approx.) cream.

The nut took about 2 hours to make and there was a reasonable amount of prep time to ensure the nut slot was perfectly smooth, clear of glue and lumps. Most of the shaping work is done using small files and a dremel is used if there is a significant amount of material to come off.

The majority of the shaping is done in a vice and when the shape and final width of the nut is correct it can be fitted with a small amount of glue.

The string spacing is very important so I use a Stewart MacDonald tool called a string spacing gauge in order to ensure accuracy. The gap between the strings edges should be the same which means the relative centres slightly increase as the string gets thicker.

One of the most important parts of making a nut is to have good files of the correct gauges. On this particular one we used 0.010", 0.013", 0.017" 0.026", 0.032" 0.048". You could use a thicker gauge file for all the strings but I do prefer the aesthetics of a nut with optimally cut slots.

To polish I use various sand papers starting with 1000 and then going through grades 1500, 2000 and 2500. Final polish is done using a dremel with Encore Scratch remover.

Strings & Setup

One of my favourite strings is the NYXL from D'addario. These are a new 'breed' of string with the same alloys as a normal Nickel Plated string but with much higher refinement of the metals. This creates a string which is stronger, more resilient to corrosion, more stable and an improved sound.

I always ensure the frets buffed and shiny to avoid any unnecessary wear and also feed the fretboard with Big Bends Fretboard Juice.

When restringing or setting up any guitar I use Big Bends Nut Sauce on the nut slot and bridge slots to ensure there is as little friction as possible. There is honestly, nothing as good as this for ensuring stability and, when combining with the brilliant NYXL, this Les Paul will stay in tune!

With a full setup and some pretty major changes this is a beautifully balanced Les Paul. There are lots of things I don't like, such as the pickups, electronics and bridge but it is a subjective world so we can just put that down to choice.

In all honesty, the Mammoth Ivory Nut makes no difference to tone over bone but does look a little different and it was nicer to work with. In this case, the customer wanted something special for a guitar they had waited a long time to get. It has made it a little more bespoke and also fixed a glaring quality control failure on Gibson's part!

Final inspection:


  • 1.5mm action at the 12th fret Bass side 1.25mm Treble side
  • Truss Rod - 0.010" at 7th fret with 1st and last fret held.
  • Intonation Perfect
  • Replaced Nut with Mammoth Ivory

Our customer would like to upgrade the pickups and electronics in the Les Paul so we will look forward to seeing this one again in the near future.

Rich Turner

Guitarist, Guitar Technician, Soundunlimited

Thanks for reading, if you have any questions or queries please do not hesitate to contact me or comment using Disqus below.