First String Buzz When Sixth String Fretted at Third Fret

[Brent Hutto]

This is a real poser to my limited knowledge. I have developed over the past few days a buzz on my first string but it is very specific. It only buzzes outright when the string is fretted at the third fret, although there is something zingy about the tone on that string at other times.

But here's the thing. This only happens if I also have the sixth string fretted at the third fret as well. As I say, I can hear a hint of a first-string problem at other times but that's the only situation that has a frank buzz at moderate to loud volumes. A couple of other things...

If I drop the sixth string down to D instead of E the first-string buzz goes away (even if I fret at the fifth fret instead of the first!)...

If I press on that third fret on the bass side without fretting the string it does not buzz...

The first-string buzz starts the moment the sixth string just barely contacts the third fret but continues no matter how hard or softly I fret either the first or sixth string...

Finally, I noticed a slightly high fourth fret on the treble side so I tapped it back down a few thousandths. All the frets are now dead level and it made no difference in the buzz. These are 12-54 gauge 80/20 Martin strings on a handbuilt OM guitar, 24.9" scale with an ebony fingerboard and nickel-steel frets. Very low action and about 0.008" relief at the sixth fret. Bone nut and saddle.

[Joshua Levin-Epstein]

Brent,

Are you certain the buzz is coming from the speaking (between the fret and the saddle) length of the string? That the buzz is worse when the low "E" is fretted makes me think the string is rattling between the nut and the fret. Perhaps the nut is cut too deeply or there is some back bow.

And let's not dismiss a bad set of strings....

Joshua

[Brent Hutto]

I'm not convinced that I've narrowed down the location of the buzz but I'm fairly sure it isn't south of the soundhole. But above the nut or the first few frets is entirely possible or it could well be coming from anywhere down to frets 12-15 or so. Pretty certain it's not a bridge or body buzz though.

For that matter the more I listen I realize it could actually be coming from the sixth (wound) string although it only happens when I play that note on the first string. I need to get a cardboard paper towel tube and try to determine for the sure which string and which end of the neck, though.

How do you evaluate possible back-bow in the neck? I know I'm almost out of CCW rotation on my truss rod (i.e. nearly as little tension on the truss rod as possible) just to get to my desired 0.008"-0.010" relief at the sixth fret, first string. But I haven't measured relief at any other location. Is that what you mean by back bow?

And I'm definitely going to do a string change in the next day or two. I've swapped out the first string but I'm going to put fresh set top to bottom and while I'm at it I may go up slightly on the gauges.

[Frank Ford]

Brent -

You might want to take a trip through my Buzz Diagnosis Pages

It sounds like you may have a "back buzz" where the portion of the string from the nut to the fretted note is buzzing against the frets as it vibrates sympathetically

[Greg Mirken]

Ooops, didn't see other replies. Back buzz sounds like the likely culprit to me.

[Brent Hutto]

Well, no surprise y'all were correct. It is a back buzz on the sixth string, second fret. With that string fretted at the third there's no daylight between it and the second fret and by touching it there I can make the buzz go away. However, if I do touch the second fret while playing G that string will actually then almost touch the first fret. So that nut slot is probably low under the sixth string.

This probably happened when we got all this rainy weather the last few weeks and the typical humidity in the house when from 45-ish to 52-ish. My neck relief went down from around 0.010" to 0.008" or a bit less over that period. Thanks so much, guys!

[Brent Hutto]

Well having determined it was a back buzz of the sixth string and figuring that nothing I do with the truss rod is going to have much effect way up at the second fret I decided the only cure was to raise that string's slot in the nut. So I laid a narrow bead of thick-style CA into the slot and dusted it with a tiny smidge of backing soda. A couple hours later I just used a piece of wound sixth string material to smooth the slot and remove some of the excess.

So now the string sits rather high in its slot but there's no back buzz and the action seems tolerable, even though it looks high. A six-string barre F chord is no problem and F, F# and G on that string seem to intonate fine. So I think I'll leave it a few thousandths too high for now. I switch between standard and Drop-D all the time and I suspect it won't take long for that string to work its way lower. We'll see.

[Greg Mirken]

Yeah, it will wear pretty quickly. For a more permanent fix, you gotta deepen the slot and inlay a piece of bone, and cut a new slot. Glad you got it taken care of.