Results 1 to 12 of 12

Thread: Could a broken truss rod cause a buzz?

  1. #1
    Registered User
    Join Date
    Dec 2007
    Location
    California
    Posts
    382

    Default Could a broken truss rod cause a buzz?

    I have 1924 A2Z that I love, but it does have an intermittent, yet persistent buzz. I've tightened every nut and bolt, replaced (professionally) the tuners and have tried to track down the source without success.

    It's even a little difficult to determine exactly where it's coming from.

    I'm wondering if it could be coming from the truss rod? The neck plays perfectly and seems to have the proper amount of relief so I'm reluctant to tighten or loosen the truss rod to investigate.

    Could a truss rod cause a buzz? If so, how would you prove it or rule it out?

  2. #2
    Registered User
    Join Date
    Mar 2013
    Location
    Brooklyn, NY, USA
    Posts
    1,073

    Default Re: Could a broken truss rod cause a buzz?

    A truss rod can cause a buzz ut it isn't all that common. You could try tightening it just a touch so as to not have an effect on the action. I would also be concerned about the possibility of a loose brace.

  3. The following members say thank you to Nevin for this post:


  4. #3
    Teacher, luthier
    Join Date
    Oct 2017
    Location
    Southeast Tennessee
    Posts
    2,037

    Default Re: Could a broken truss rod cause a buzz?

    It rarely happens, but yes it could. It is more likely that the buzz is coming from somewhere else, though.
    A buzz can come from a loose seam between the top or back and the sides, or between the fingerboard and the neck. The top brace should also be checked. And make sure the tailpiece is not almost touching the top.

    Tap around on the instrument and see if you can isolate the general location of the buzz.
    Tap around the edges of the top and back where they meet the sides. Then tap in several places on the back of the neck, then do the some on the fingerboard. Also examine the binding and see if you can see signs of a loose spot. Inspect the bridge also.

    A broken rod should be fairly obvious. But sometimes a rod that is not broken can develop a vibration also.

    If you still suspect the rod, ensure that the truss rod adjusting nut is not loose. If it is, see if you can snug it up with only a minimal effort.

    Buzzes can be hard to track down. Sometimes they appear to be coming from one area when the real cause is some place else.

    If you still can't find anything, get thee to the most experienced repair person you can find.

  5. The following members say thank you to rcc56 for this post:


  6. #4

    Default Re: Could a broken truss rod cause a buzz?

    Quote Originally Posted by Bill Foss View Post
    The neck plays perfectly and seems to have the proper amount of relief so I'm reluctant to tighten or loosen the truss rod to investigate. Could a truss rod cause a buzz? If so, how would you prove it or rule it out?
    You have nothing to lose to make sure it is snugged up and not loose or rattling. Snugging it up (if it isn't already) is not going to effect the neck relief.
    But Amsterdam was always good for grieving
    And London never fails to leave me blue
    And Paris never was my kinda town
    So I walked around with the Ft. Worth Blues

  7. The following members say thank you to Fretbear for this post:


  8. #5
    Registered User
    Join Date
    Mar 2013
    Location
    Brooklyn, NY, USA
    Posts
    1,073

    Default Re: Could a broken truss rod cause a buzz?

    Just a thought, are you always playing it in the same place? It could be a sympathetic vibration in the room.

  9. #6
    Moderator MikeEdgerton's Avatar
    Join Date
    Mar 2007
    Location
    40.1646 N, 74.2083 W
    Posts
    24,274

    Default Re: Could a broken truss rod cause a buzz?

    Have you walked through Frank Ford's Buzz Diagnosis pages from Frank's www.frets.com?
    "Bargain instruments are no bargains if you can't play them". These are the words of J. Garber.

  10. The Following 4 Users Say Thank You to MikeEdgerton For This Useful Post:


  11. #7
    Teacher, luthier
    Join Date
    Oct 2017
    Location
    Southeast Tennessee
    Posts
    2,037

    Default Re: Could a broken truss rod cause a buzz?

    One other thing to check-- if it has the original pickguard, the part that butts up against the fingerboard will have a second piece of plastic laminated to the bottom of the pickguard to help hold the nails in place. Make sure that this piece is not delaminating from the rest of the pickguard.

  12. #8
    Registered User
    Join Date
    Dec 2007
    Location
    California
    Posts
    382

    Default Re: Could a broken truss rod cause a buzz?

    These are all great suggestions and will follow up. The two piece back had to be re-glued at some point, so checking all the seams is a good idea.

  13. #9
    Registered User
    Join Date
    Jan 2009
    Location
    S.W. Wisconsin
    Posts
    5,868

    Default Re: Could a broken truss rod cause a buzz?

    I have had truss rods buzz that were not broken, or loose. It's a pain to find, but it can be fixed. It was in a guitar tho and I doubt the same problem would exist in a short scale neck like a mandolin.
    THE WORLD IS A BETTER PLACE JUST FOR YOUR SMILE!

  14. #10

    Default Re: Could a broken truss rod cause a buzz?

    One way to find a buzz is to make it continuous, and louder. Tapping and string plucking are helpful, but providing a continuous energy source is better. An audio oscillator and any type of transducer, like a piezo or a little speaker, and apply it to one or more areas. Sweep the frequency. Some, probably most buzzes will happen because of a resonance; others are wide-band and respond to amplitude. When the buzz is energized continuously, you stand a chance of locating it by damping parts with, say, a finger, or for internal buzzes, an appropriate probe.
    That is, if two parts, an open seam, a loose piece of hardware is generating a sound by impact, closing the gap between the parts or immobilizing the part will stop the buzz.
    In machinery, this is how it’s done because a ‘buzz’ means something’s loose and will cause wear or failure. It’s also important to find resonances that can be problems. I don’t know if it’s common in the instrument repair world, but sure is easy to do.

  15. The Following 2 Users Say Thank You to Richard500 For This Useful Post:

    ajhBill Foss 

  16. #11
    Registered User j. condino's Avatar
    Join Date
    Nov 2005
    Location
    Asheville, NC
    Posts
    2,097

    Default Re: Could a broken truss rod cause a buzz?

    A loose truss rod is more common than a broken one. They can cause a bad buzzing sound all the time or at certain frequencies they can cause a loud wolf tone.

  17. #12
    Adrian Minarovic
    Join Date
    Oct 2003
    Location
    Banska Bystrica, Slovakia, Europe
    Posts
    2,804

    Default Re: Could a broken truss rod cause a buzz?

    Quote Originally Posted by j. condino View Post
    A loose truss rod is more common than a broken one. They can cause a bad buzzing sound all the time or at certain frequencies they can cause a loud wolf tone.
    On old Gibson with curved truss rod buzz is much less likely than on straight rod. There were cases when the inner nut inside the heel was loose and slowly fell off the rod, but in such case the upper nut can be tightened without much resistance and it pulls the rod out of the neck till it bottoms out on the end of the thread. Good luthier can check this and you can get a RTG done for few $ to see the heel end of rod...
    Adrian

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •