Nuts, more nuts, and string spacing gauges

[fender3x]

A few days ago I installed a new nut in my acoustic. I got a tusq nut because it was the only one I could find that had a slanted bottom. For some reason my MIJ Fender has a nut that meets pretty much the exact specs of old Martins.

I cut the nut carefully, and 5 of the 6 strings sounded great. The D string, however, had a rattle. Not so much of a buzz like what you'd expect over a fret, but a rattle...like something is lose. Since it did not have this rattle before putting in the new nut, I assumed that was it. I measured, and the slot seemed right. In an abundance of caution I used a fret leveling tool to take down the fret a couple of thousands of an inch for the D string. When that did not work, thought maybe I had gotten the slot too flat. So I increased the break angle at the back of the nut. When that did not work, I thought maybe I had gotten the slot too wide. So I filled the slot with baking soda and superglue. This morning I re-cut the nut with a narrower slot...just about the exactly width of the string measured with a Vernier caliper. Cut carefully, and left the slot so that the string would be a little high.

None of these things have gotten rid of the buzz. I have a new nut arriving today, but before I ruin it too... what else could be causing this rattle? It sounds like it's coming from the nut. When I put my ear to the fretboard that's where it's loudest. I don't think it's fret buzz. Any thoughts? ...and thanks in advance!

[Simon Barden]

Have you tightened the nuts on the tuners (if they aren't held on by rear screws)? They vibrate loose over time, ride up a bit and then the washer can vibrate between the tuner nut and the headstock.

[McCreed]

Good suggestion from Simon. I've experienced the loose tuner nut before!

Also, are you positive it's coming from the nut? It may sound crazy, but sometimes the sound (buzz, rattle, sizzle) can be getting generated at the bridge but convincingly sound like it is at the nut (and vice versa).

Secondly, have you tried a different D string? A defect in the string can cause inexplicable sonic weirdness too.
Maybe try checking the D string's retainer is seating properly under the bridge.

That's all I got...

[fender3x]

I got the buzz to stop. As Simon suggested it seems to be that the nuts on the tuners had loosened. Five of the six were loose enough for the washer to rattle. McCreed gets a few points too because I put my ear up to the machines as well, but could still swear that I was hearing the rattle from the nut rather than the tuners.

Who would have thought that a machine nut might come loose after only 36 years? I can hear you thinking "pretty much everyone." I should probably write Mr. Gotoh a thank you letter that the machines haven't given me a lick of trouble in all this time, other than the need to adjust the tuner nut every 36 years or so.

Thank you!

[McCreed]

Great result! (and easy fix!)

Mr. B's intuition pays off again.

[Trevor Davies]

"Who would have thought that a machine nut might come loose after only 36 years?"

Not me. You must be jumping around to much when playing.

[Simon Barden]

You're not playing it enough. They generally come loose (e.g. need a 1/4 turn or so to tighten) very quickly on a well-used guitar.

[fender3x]

You're not playing it enough. They generally come loose (e.g. need a 1/4 turn or so to tighten) very quickly on a well-used guitar.

Well there's no telling how long the nuts have been loose. When I looked at the wear and tear on the fingerboard it certainly looked like it had been played. That may be a near future project. That said, I'll try jumping around more ;-)

Sent from my ONEPLUS A3000 using Tapatalk

[Simon Barden]

For some reason my MIJ Fender has a nut that meets pretty much the exact specs of old Martins.

Probably because they copied an old Martin for early acoustic guitar designs (a lot of Fender acoustics have the Martin shape headstock) and have stuck with the dimensions.

[fender3x]

Probably because they copied an old Martin for early acoustic guitar designs (a lot of Fender acoustics have the Martin shape headstock) and have stuck with the dimensions.

That would make sense, although it seems harder to build that way. Martin doesn't even do it on guitars worth 5x what mine's worth. I thought about the degree of difficulty and time involved with shaping a nut blank to get that angle, and decided to see if I could buy one pre-cut. The only one I have found was tusq and labelled "Martin." If they had used any other angle I'd have been SOL.

It's a funny guitar. Beautiful rosewood sides and back--which is bookmatched. Three tone sunburst spruce top. Now that I have the old nut off, I can see that it was bone. Bound all around, including the point of the Florentine cutaway and the bottom of the heel. It has a big, full sound, and great tone. Worth about $200 on a good day. One of the best, worthless things I have ever owned.