PRS SE custom 22 - deformed nut groove


New Member
Dec 21, 2023
I bought a PRS SE custom 22 about a year ago. Didn't play much since it kept horrible tuning. Recently i've decided to deal with the problem by replacing the nut with TUSQ XL. After the removal I've noticed that the profile of the nut's groove is not exactly right-angled (see the attached images). It also seems that the original nut was shaped to fit this strange groove.

So essentially the problem is that now I can't really install the TUSQ NUT (see the other image) without reshaping it or the groove itself. I don't have much experience with PRS's, but is this normal? Any experience with such a phenomenon? Appreciate your help. Please see the included images (links)

The groove without the original nut
Trying to put the TUSQ XL in its place - you can see that it doesn't really sit well, living an opening between the nut and the fretboard edge.
First, that nut is too wide. It extends past the nut seat (where the nut fits to the neck). When ordering a GraphTech nut you need to match these specs:
1) length
2) width
3) height
4) string spacing
5) fretboard radius

You can’t change string spacing, but can adjust the other variables via sanding or filing. Again, unless you have the right tools, leave it to a pro. They can do it quickly and accurately.

Those measurements should be taken with a caliper (use metric, since GraphTech is in Canada and mm are easier to use for small measures). GraphTech has a simple tutorial on their website. These measurements are critical…they sell tons of different pre-slotted nuts and the differences can be as small as tenths of a mm.

You could start with a Tusq blank and have it shaped to match, but that requires more labor, making and it more expensive in the long run.

That said, the nut seat on your guitar is poorly cut. Your nut would rock back and forth on that seat, especially if you use a tremolo. The nut seat should be perfectly flat, cut at a sharp 90 degree angle..that allows maximum contact across the nut. Luthiers/techs use a specific type of file for this. You can’t do it accurately with regular files.

Proper preparation of the the nut seat ensures maximum contact between nut and neck. Better contact = better tone and sustain, plus reliable intonation and tuning stability. The nut should seat perfectly, with no gaps. The glue (only two drops of superglue) is only applied to keep the nut from falling off or sliding when string tension is removed…glue it is not meant to fill gaps.

Again the nut seat is poorly cut. No nut will fix that. Less likely is that finish overspray disrupted the seat surface. Either way, they failed to properly prepare the nut seat. It has to be filed and squared. If you bought it new, contact PRS for warranty repair or replacement. This is a manufacturing defect, not wear and tear. All SEs are inspected and QC’ed at the main factory in Maryland. They should have caught this and fixed it.

Just curious…did you consider using the PRS Core nut? They are brass-infused composite. The specs would be a match and the nut would require very little, if any, adjustment to fit. Just make sure to measure the neck width…PRS sells two nut sizes, “Wide” and “Regular”. They are cheap …$15 for a two-pack. It is a big improvement over the stock plastic SE nut. Far and away the cheapest mod to improve tone transfer and sustain.
Thank you for the detailed response. As I thought, there was some manufacturing error with this nut carve, but unfortunately I cannot activate the warranty. I bought the guitar almost new but still second hand (should have checked better...). I did consider the PRS Core nut, and its still an option for me, but as you said this will not fix the issue. So it looks like i'm only left with two options: either take to a luthier, or try to do it myself. If I was planning on doing it myself, what kind of file/tool should I use? I assume its completely rectangular in shape. Do you have a specific suggestion?
Something in that picture does not look right to me. On every single PRSi I own, the nut sits flush with the neck at the top of the fret board. Your picture shows the nut riding on top of a carved out section of the fret board. In the current state, no nut will fit properly.
here is what the nut/neck, fretboard interface should look like:


not a PRS but same idea
Wow, that's a huge difference. I thought, the problem is just the angle, but it seems that there is a lot of excess material underneath the nut in my case. I guess its possible to fix this.. anyone here has any experience with that?
I’d get a bottle of tequila, a little one inch wide stick, and some sandpaper and remove some of that wood until it’s perpendicular with the fretboard.

Then I’d dry fit the new nut, see if it needs to go any lower, and if it does put a piece of sandpaper on the table with the tequila, and lightly sand the bottom of the nut until it’s the right height.

Then I’d glue it in.
I wouldn't have played it much either...
Look at the height of the string over the first fret.o_O