Buzzing C string in bridge/bridge pin

I am having some difficulty with a buzzing C string. The bridge has bridge pins and the buzz does not happen when the string is played open only when it is fretted and more when it is fretted up near the headstock. I have read about some possible causes like too low action and buzzing on a fret but the buzz is definitely coming from the bridge and if I apply pressure to the bridge pin the buzz goes away. The first thing that I tried was to take the string out and trim any excess on the knot and restring making sure that the knot was pulled tightly against the bridge plate when I re-strung. When that did not fix the problem I made a little slot in the bridge right in front of the bridge pin hole so that the string thickness would not prevent the pin from being properly seated. I have also read that it is possible that the saddle is too low but I am not sure why that would make just the C string buzz. I have thought about trying a wound C string that will have a smaller diameter but I am not sure how that will help. I am using 5 degree bridge pins from stew mac and the matching 5 degree bridge hole reamer. Has anyone else had this problem and how did you resolve the issue. Any help would be greatly appreciated.

is this the original string that came with the uke?

No buzz on the open string? Doesn't sound like the bridge pin. I'd be suspecting the saddle or its relationship with the string.

Just built the uke so the strings are the first that I put on. They are aqulillas with a wound low G.

Do you mean that the saddle is too close to the bridge pin, it is not tight enough in the slot, or it is not seated correctly, or the shape of the top of the saddle is not correct?

You built this uke? Cool! Congrats. Are all the frets level? Silly question, I know. Is the action too low?

The frets are level and the action is 0.015 at the first fret and the 0.09 at the 12th fret. I have not noticed any buzzing on the frets just at the bridge where the bridge pin is.

It may sound like the bridge is buzzing when the problem is actually a high fret. Buzzes have a tendency to travel. The fact that the buzz disappears when you apply pressure to the bridge pin could be that you are adding just enough tension to clear the high fret. Try shimming the nut to raise it slightly, or partially fill the C-string slot with a bit of CA glue.

No, leave the nut alone. If it's not buzzing on open strings then we can rule the nut out.

From your description that the buzzing stops if you press down on the bridge pin I'd suggest looking first at:

1. Whether your pin is under-size or distorted. Swap it for one of the other pins to see what happens. If there's still buzzing which stops when you press the C pin, wrap a little tape round the pin and try again (you might have reamed the hole a tiny fraction too large). In fact, as you've cut a slot you could tune up (carefully) without the pin in place to see whether the buzzing disappears.

2. Whether you have a duff string. It might be slightly thicker in one place, just enough to hit a fret when the height at the 12th is reduced by fretting. I make .09 to be 2mm, which seems to me to be right on the low side of non-buzzy action, so even a fractional bulge in a string could cause a problem. If you can, swap the string end-for-end to see if the buzzing goes away or moves to different fretting or changes in sound. Also, does it buzz when you fret at the last fret? Work out which frets it does buzz when played, to see if things change with a change of string.

3. Whether a section of the bracing near the bridge has come unglued. Harder to diagnose, but I've had some success fabricating a bent stick and using it to press on each brace at 1 inch intervals as I pluck the offending string. You'll need a third hand to fret the string (or a capo - pencil + rubber band should work). Pressing on the pinmight be enough to stop a loose section from vibrating.

If it's none of those, all you can do is systematically eliminate every possible cause - tedious work, but very satisfyng when you finally track it down.

Good luck - buzzes are elusive things. I had one which was definitely heard coming from the saddle, but was actually caused by an unglued brace section.

No, leave the nut alone. If it's not buzzing on open strings then we can rule the nut out.

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I wasn't suggesting that the buzz was at the nut. It sounds to me like a fret problem since the buzzing is worse when fretting near the headstock. Shimming the nut slightly will raise the action along the fretboard, lifting the string enough to clear whatever fret may be causing the problem. It is a quick and easily reversible test to see if the problem is with a high fret. If there is no change after shimming, make sure that the top of the saddle is nice and round as a flat spot could cause the buzz.

Does it buzz all the way up the neck? Or does it stop once you pass a certain fret? If so then it's most likely a high fret. It may be that the action is just a bit too low for this string set. You could try putting a shim under the saddle to get it up to .095 or a bit more.

Another one may be that the top of the saddle doesn't have a single contact point to the string, but this tends to produce a sitar type buzz.

And sometimes its that the saddle doesn't have nice clean contact with the bottom of the saddle slot. That one can drive you mad trying to track down. Now I always pull the saddle out and flatten the bottom on a piece of float glass with sandpaper on it should a buzz like this show up on the work bench.

Sometimes Aquila "C" strings can be a pain in the a**. They are very "floppy" and have a large circle of rotation -which leads to buzzing. Try a wound "C" from a different set.

Thanks for all the ideas. I tried a number of things tonight and have not fixed the problem. I made a new saddle that made a little higher action and had a definite single contact point for the string. I also replaced the C string with a new string. Finally, I put a little bit of tape on the bridge pin to see if maybe I reamed it out a little too much. This also did not fix the problem. I also rechecked to see if the frets were level. The buzz stops at when you move up to the 7th fret. I will try a wound C string next after that I am not sure.

I had a guy in my shop last week with a buzz in his guitar that he could not figure out. At first, it sounded like a loose truss rod or something in the neck. Turns out, the neck was coming off the body. This was a Seagull guitar with a bolt on neck. I had to remove the paper label on the inside neck block to expose the head of the bolts and turn the bolts one full turn to tighten the bolts back up. The washer between the bolt heads and the neck block was the problem.

Your problem seems to be something else, but keep searching, you will find it. Maybe you could have some other luthier look at it, sometimes fresh eyes and ears can help.

BlackBearUkes said:

I had a guy in my shop last week with a buzz in his guitar that he could not figure out. At first, it sounded like a loose truss rod or something in the neck. Turns out, the neck was coming off the body. This was a Seagull guitar with a bolt on neck. I had to remove the paper label on the inside neck block to expose the head of the bolts and turn the bolts one full turn to tighten the bolts back up. The washer between the bolt heads and the neck block was the problem. .

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Watch out for the new seagulls as they changed their neck joint system- now they glue in a tongue totally connecting the neck to the body, so to reset the neck, you have to saw through the thing. I had to do it to 10 brand new ones...