String Intonation

[Steverz]

2012 Gibson SG Standard with tune-omatic bridge: I recently changed my guitar strings and moved from the Gibson Light Gauge 10s to the Rev. Willys Number 8 (nickname for Billy Gibbons from ZZ Top). This really screwed up my intonation. So, I adjusted the intonation (open string in-tune then fretted at the twelfth using a Boss Tuner). The intonations are fine for each open-to-fretted-twelfth fret string, but the g,d,a strings, especially the famous g string, when fretted at the second fret are sharp, not only to the ears but on my tuner.

 

Every video is see is the same where the sharp notes are high on the neck while playing fine on the lower frets. As you have just read, my issue is exactly the opposite where the problem is the lower three frets but fine higher up.

 

What am I missing?

 

(fyi, I bought this guitar new from Guitar Center in 2012 and it was still in the box from the Gibson Guitar factory. So, this instrument has never been serviced as nothing has been wrong since I bought it, until now with the changing of the string gauge.)

 

THANKS...........

[merciful-evans]

2012 Gibson SG Standard with tune-omatic bridge: I recently changed my guitar strings and moved from the Gibson Light Gauge 10s to the Rev. Willys Number 8 (nickname for Billy Gibbons from ZZ Top). This really screwed up my intonation. So, I adjusted the intonation (open string in-tune then fretted at the twelfth using a Boss Tuner). The intonations are fine for each open-to-fretted-twelfth fret string, but the g,d,a strings, especially the famous g string, when fretted at the second fret are sharp, not only to the ears but on my tuner.

 

Every video is see is the same where the sharp notes are high on the neck while playing fine on the lower frets. As you have just read, my issue is exactly the opposite where the problem is the lower three frets but fine higher up.

 

What am I missing?

 

(fyi, I bought this guitar new from Guitar Center in 2012 and it was still in the box from the Gibson Guitar factory. So, this instrument has never been serviced as nothing has been wrong since I bought it, until now with the changing of the string gauge.)

 

THANKS...........

 

You obviously have a good ear! The string gauge change will affect intonation slightly.

 

Adjust the saddles to correct it. From memory, the adjustment should be back towards the tail. In other words, lengthen the string slightly by winding the saddles back.

 

(If I'm mistaken, then shorten the string by a small amount.)

[RockyA]

Apparently you have intonated the strings, but I think this is your problem. Now that you went to such super light gauge strings your neck needs adjustment and that is why just the dga. Put capo on first fret, then in playing position press down 22nd fret, take a business card and see if it will fit between the bottom of the Low E and the 7th fret. Take your truss rod cover off and use your truss rod wrench that came with the guitar. I would assume you need to add more relief, so loosen truss rod by turning it in direction of the high E until the business card will slip between low E and 7th fret. Adjust till it does just a 1/4 turn at a time. Then check the high E side, holding down 22nd fret and seeing if there is slight relief at the 7th fret, just tap the sting with your finger, if it moves you are fine.

 

Before you do this adjustment though, I would recommend measuring you action at the 12th fret, Bottom of Low E and top of 12th fret and bottom of high E and top of 12th fret and write it down. The truss rod adjustment may change the action an this way you can reset your string heights at the 12th fret.

 

Then intonate the strings again after a day or so to let the neck adjustment and strings settle in. Then you should be good to go.

[capmaster]

Like RockyA said, the neck will likely call for a readjustment. There is 36% less string tension now, and this will make any neck bend backwards, given the adjustment was fine before. Rotating the truss-rod nut counterclockwise will help. How much correction will be required is hard to predict, but to my guess it probably will be within a 1/3...1/2 of a turn, respectively 120°...180°. It may take seven to ten days until the adjustment has stabilized, and perhaps a final slight correction some months later.

 

The correct order of adjustments is neck relief, string action, and finally intonation. Good luck!

[Searcy]

I think the problem is that your left hand of used to 10s but now you're playing 8s.

 

I think you are fretting too hard and bending the notes sharp .

[Rabs]

What Searcy says is also true..... I have heard that if you use light strings, youd better have a light touch....

[rct]

I think the problem is that your left hand of used to 10s but now you're playing 8s.

 

I think you are fretting too hard and bending the notes sharp .

 

I agree. Strings that light are bound to reveal a high fret here and there.

 

rct

[merciful-evans]

 

Every video is see is the same where the sharp notes are high on the neck while playing fine on the lower frets. As you have just read, my issue is exactly the opposite where the problem is the lower three frets but fine higher up.

 

 

I completely missed this on 1st read Steve. Sorry. I thought your problem was in the upper neck region.

 

As for the possibility of pushing the lighter gauge strings sharp. That should be quick & easy to check. It seems a less likely cause if its happening on the lower strings also though.