Gibby sounding wonky

deebeewhy

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I am distressed that in under 3 years and less than 300 hours, my Gibson Keb Mo (00 style) - which I absolutely love - is now 10-12 cents sharp fretted at the 12th on the B and low E. Am I out of line thinking it's a bit early for intonation issues? Let me know! Thanks.
 

AcornHouse

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The intonation on an acoustic can only change if the gauge/brand of strings are different than factory spec, or there is major movement in the neck. The intonation is merely the distance from the 12th fret to the saddle, adding compensation for the string thickness.
If it was good when you first had it, unless that distance has changed, then the string thickness has changed; which can cause an intonation issue.

The solution is to go back to the original spec strings, or have a new saddle cut and bevelled to your new string preference.
 

Westerly Wood

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or just get a proper setup, should be fine, especially as you like it so much, i think a periodic setup is great to do.
 

adorshki

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Huh, missed this yesterday, but agree most likely issue is simply new set up needed, perhaps a little normal "settling" of the entire construction has occurred.
(By the way I'm with Acornhouse about using factory spec string gauge, I'm positive that if nothing else it'll prolong the life of the instrument)
I assume it's got adjustable truss?
Over that period of time and playing a bit of neck bowing from string tension would be normal I think, especially if string gauge was upped.
First thing I'd do is check neck for bowing and add some backbow (tighten the truss) if needed.
I was doing that a couple times a year for the D25 for awhile (first 3 or 4 years I think?), by maybe 1/8 when needed.
Overall think I've added less than half a turn total though.
"They" say necks'll do that, "settle in" and then stay stable for a long time.
Have also heard that about the actual set at the heelblock joint, but I know technically the straightness and the angle are 2 different issues.
IF your neck is at the straightness you like (a little bit of relief is good for hard strummers), then sure maybe it's time to lower the saddle a wee bit.
 

kakerlak

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If the fretted notes have grown sharp, then it means the break-over point on the saddle and the 12th fret are closer together than they used to be. It could be the neck pulling into the body a bit or the top torquing towards the neck (string tension works to fold the nut and saddle towards each other). It's also possible, especially if it has a tall saddle, that the saddle has begun to distort or lean forward, as string tension will work to do that, too. Check neck relief -- flattening it out, if there's room, will increase the scale length slightly, and might correct intonation a little. Eyeball the saddle. Try humidifying it a bit -- that might swell things back up if it's collapsed in on itself a bit. Barring that and, if it still plays well, you might look to rework the saddle or have a new one cut that's ramped towards its back edge, rather than crowned in the middle.
 

deebeewhy

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Thanks, guys, for all this solid advice. Because I have never parted from spec strings, I will pursue the issue as one related to the saddle, as you suggest. Thanks much. Daniel
 
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