Picking Open G string makes Truss Rod vibrate

Scubaman

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I wonder if you guys might be able to help me with a weird problem which has suddenly appeared on my Epi Dot Studio. When I pluck the Open G string there is a metallic sympathetic vibration which seems to be coming from the truss rod. If I put my ear to the neck it definitely sounds like it's the truss rod and if I put a truss rod wrench in the socket I can feel the vibrations. The truss rod nut doesn't feel loose and the truss rod works fine so I was wondering if it has somehow come loose in the channel and short of removing the fretboard (would cost more than the guitar is worth), is there anything I could do to fix it.
 

David Collins

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First step is to make absolutely sure the rattle isn't coming from somewhere else. It's quite common for vibrations in one area to transmit through the instrument and give the illusion of coming from another source. Tightening and loosening the rod to observe if this has any effect is one part of diagnosis, along with checking all other possible suspects thoroughly.

If it is the rod, there are other approaches you can try. This is a relatively common problem on some Fender necks, and the typical solution is to remove the dots at one or more of the 5th, 7th, or 9th position markers. Then a smal pilot hole is drilled and tapped for a small set screw (I usually use 4-40). When the set screw is installed and tightened to snug up any slop in the rod, new position markets are reinstalled to cover them.

With that neck I'm not sure exactly of the truss rod type though. If it has an aluminum housing then it may involve drilling and tapping through this to snug up any slop in the rod. If the rod is diagnosed as the source of the noise though, this is an old and time tested remedy which has proven to be quite effective while much less invasive than approaches pulling the whole board.
 

Scubaman

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First step is to make absolutely sure the rattle isn't coming from somewhere else. It's quite common for vibrations in one area to transmit through the instrument and give the illusion of coming from another source. Tightening and loosening the rod to observe if this has any effect is one part of diagnosis, along with checking all other possible suspects thoroughly.

If it is the rod, there are other approaches you can try. This is a relatively common problem on some Fender necks, and the typical solution is to remove the dots at one or more of the 5th, 7th, or 9th position markers. Then a smal pilot hole is drilled and tapped for a small set screw (I usually use 4-40). When the set screw is installed and tightened to snug up any slop in the rod, new position markets are reinstalled to cover them.

With that neck I'm not sure exactly of the truss rod type though. If it has an aluminum housing then it may involve drilling and tapping through this to snug up any slop in the rod. If the rod is diagnosed as the source of the noise though, this is an old and time tested remedy which has proven to be quite effective while much less invasive than approaches pulling the whole board.

David, really appreciate your advice. I've been all over the guitar to try and isolate the problem (bridge, pickups, wiring, etc) and it definitely seems to be the truss rod. Tried loosening and tightening to see if that would fix it but no. I've tried tapping the neck (with increasing levels of application but nothing seems to rattle) and I've tried to replicate the problem on different strings and at different frets but it only happens when the G string in picked un-fretted. I also raised the action way up to remove the possibility of it being a fret.

AFAIK Epiphone use exactly the same type of single action truss rod as Gibson so time to build up the courage to drill out a couple of side markers.
 

David Collins

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Noooo! Not side markers - fret board markers - the ones right over the truss rod in the middle of the fret board!

I'm still not convinced the diagnosis is certain though. Do you have an experienced tech around you could get a second opinion from? Obviously you have the guitar in from of you and we have the diagnostic disadvantage of only being able to extrapolate from limited descriptions. From what I've heard described though, I could just as easily diagnose it to be an issue with the g string nut slot.

It doesn't make this noise when you play the same G on the D string, or tune the string down a step or two and play G on the first or second fret? Is it certainly tied to only a frequency, and not a position? It doesn't go away when you press or dampen strings behind the nut? Does it change at all when you flex or stress the neck while playing?

There are lots and lots of tricks and tests that can help deliver a diagnosis I greater certainty. An experienced tech should be able to tell in minutes what may take someone who hasn't seen as many issues days. If you have a trusted shop around, I would definitely recommend the visit. It would be a shame to start drilling holes without be certain of every detail regarding why it's needed, how to do it, and what to watch out for that could go wrong.
 

DavGrape

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stmfitr636

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I had (and did, nearly) the same with an acoustic with a rattley truss rod.

I drilled out the 7th fret marker (or was it the 9th) and then drilled a small hole to the truss rod. I inserted a small dowel (read: baboo skewer) and glued and clamped to push down against the truss rod.

After a day, I redrilled (very carefully) for a new pearl dot and leveled it carefully as to not hit the fretboard. I still did a bit but cleaned it up with micromesh. A small sanding block works wonders here.
 

nhayun

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Had the same thing once and it was driving my crazy! I was sure it was the truss rod as well.
In the end I have found it was from the tuner! The tuner nut was loos and the washer was rattling...
 

etzeppy

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Had the same thing once and it was driving my crazy! I was sure it was the truss rod as well.
In the end I have found it was from the tuner! The tuner nut was loos and the washer was rattling...
I had exactly the same the thing once. Took me weeks to find it.
 

jonas335

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David, I wish I had read this solution a few months ago. I had a loose rod after I put the filler strip in but before the fretboard went on, I didn't get it in deep enough, I guess. I wound up chiseling the filler strip out and redoing it...luckily it came out fairly well and my repair was successful.
 

Scubaman

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Noooo! Not side markers - fret board markers - the ones right over the truss rod in the middle of the fret board!

I'm still not convinced the diagnosis is certain though. Do you have an experienced tech around you could get a second opinion from? Obviously you have the guitar in from of you and we have the diagnostic disadvantage of only being able to extrapolate from limited descriptions. From what I've heard described though, I could just as easily diagnose it to be an issue with the g string nut slot.

It doesn't make this noise when you play the same G on the D string, or tune the string down a step or two and play G on the first or second fret? Is it certainly tied to only a frequency, and not a position? It doesn't go away when you press or dampen strings behind the nut? Does it change at all when you flex or stress the neck while playing?


There are lots and lots of tricks and tests that can help deliver a diagnosis I greater certainty. An experienced tech should be able to tell in minutes what may take someone who hasn't seen as many issues days. If you have a trusted shop around, I would definitely recommend the visit. It would be a shame to start drilling holes without be certain of every detail regarding why it's needed, how to do it, and what to watch out for that could go wrong.

I did actually mean Fret markers NOT side markers (it was getting late when I responded). Mind you it's not quite as simple a job as it would seem - the Dot Studio doesn't have fret markers so I'd have to make a matching rosewood plug.

Before I do I'll go through the guitar again but:

1.) Unlikely to be the nut as it was professionally cut and I haven't changed string gauge (actually haven't changed the strings either)

2. Checked the tuners and they are all tight.

3. Not the pickups as I removed them from the body - still the same problem.

4. Damping the G string behind the nut cures the problem.

5. Stressing the neck has a slight beneficial effect

6. Not buzzing on the first fret (which I thought might have been the problem) or indeed any of the others.

7. Swapped bridges and still occurs so not bridge rattle

8. If you hit the base of the neck with the palm of your hand you can hear the truss rod move.

9. I've even pulled the harness out through the f hole (what a pain in the a**e that is) to see if that was causing it but no difference.

More than happy to try any other suggestions that you may have towards tracing down the problem.

There nearest local luthier/tech to me (also used by all the local guitar shops) is never going to touch any of my guitars, despite him apparently being responsible for setting up some big name players guitars, after the butcher job he did on my LP nut. The nut was/is perfect but the guitar looked like he'd used a blunt cold chisel to get the old one off and prep the slot. Also charged me (6 years ago) £180 to replace the nut, swap the covers on the pickups (covers provided by me) and resolder the leads to the pots. Didn't include any sort of setup or even new strings.

The vibration doesn't seem to translate electrically so quite possibly I'll just have to live with it.
 

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