Intonation issue? Nut depth?

[misterwhizzy]

My Les Paul's G string is pretty flat at the first fret and progresses to in-tune at the twelfth. It's in standard tuning and is setup with 10-46 strings. How do I diagnose and fix the problem?

[NotCardio]

Re: Intonation issue? Nut depth?

I don't know the answer to this, but I do remember a guitar tech who once told me that it was impossible to get perfect intonation on the G, you can only approximate it.

[beaubrummels]

Intonation issue? Nut depth?

Hmm, if it’s flat, the string is too long, but if it’s ok at the twelfth, moving the saddle wouldn’t fix it. Maybe you need a Buzz Feiten nut?

[AlexR]

Re: Intonation issue? Nut depth?

Edit - read wrong

second try: typically it would be sharp at the first.
If all other strings are the typical intune to sharp, and the saddles are also in the typical staggered position, then I can only think of a individual string issue.

[ItsaBass]

Re: Intonation issue? Nut depth?

First, check that the bottom of your nut slot is about the same distance from the fretboard as the top of the first fret is. If it is slotted too low, this problem could result.

If it is the right depth, you can notch your nut back bit by bit in the area of the G string only. An angle is fine; the notch need not have parallel sides.

The shorter-than-normal scale of the Gibsons, coupled with the low tension of the G (usually the lowest tension string on the entire guitar), makes the G problematic on a Gibson (a Fender too, but more so on the Gibson), as the string doesn't bend far enough sharp when fretted in the lower register of the string.

All that being said, you should be judging intonation more based on commonly played chords than on single notes. What looks funky on a tuner, or even what sounds funky to the ear when played alone, might actually sound more in tune as part of a chord, i.e. how you might actually be most likely to use that note in real world playing.

[NotCardio]

Re: Intonation issue? Nut depth?

Never knew that about the nut/first fret relationship. Thanks.

[GuitarDoc]

Re: Intonation issue? Nut depth?

Intonations problems, especially on the "G" string are very common. And actually, it's not JUST the G string...none of the strings on a guitar can be perfectly intonated. It's the nature of the beast. However, it's especially bad on the G string. Intonatable bridges only party compensate for the tuning issue on guitars.

60 years ago I discovered that it was possible to partially compensate for the G string issue by putting a toothpick under the string just in front of the nut essentially moving the nut closer to the bridge and shortening the scale on the G string. This temporary fix led me to develop my compensated nut design. There are others who have also designed compensated nuts...Earvana, Feiten, etc.

All of my guitars get my compensated nut. That, in conjunction with a good intonatable bridge, essentially allows all of my guitars to play in tune anywhere on the neck. Even open notes and cords.

Try the "toothpick trick" and see if it helps. If it does, invest in a compensated nut.

[misterwhizzy]

Re: Intonation issue? Nut depth?

My mistake. It’s sharp close to the bridge.

[AlexR]

Re: Intonation issue? Nut depth?

Ok, that sounds way more normal.

All of the open to 1st fret changes are most likely to be sharp. The G is worst of all due to mass/pitch ratio. If the not slot is the right height compared to all other strings, then you either adjust the saddle so it will be closer down low for open chords (but maybe flat further up) or live with it.

[nexion218]

Re: Intonation issue? Nut depth?

My mistake. It’s sharp close to the bridge.

If it gets sharper going towards the bridge, than it might just be a simple case of intonation. "Chase the tuner": if it's sharp on the higher octaves/harmonics, move the saddle away from the neck, if its flat, then move the saddle towards the neck. Might be missing something here thoguh, as it sounds too simple for a solution...

[GuitarDoc]

Re: Intonation issue? Nut depth?

My Les Paul's G string is pretty flat at the first fret and progresses to in-tune at the twelfth. It's in standard tuning and is setup with 10-46 strings. How do I diagnose and fix the problem?

Easy fix.

What you describe is very typical, especially for the G string. If you adjust the tuners and bridge so that the G string is in tune at the 12th fret, then it will be slightly flat open or at the 1st fret. To test a potential solution, like I mentioned earlier, just put a 1/4" length of toothpick under the G string at the nut (making sure that the string actually rests on the toothpick). This will obviously make the G string sharper. You can move the toothpick back and forth to get the intonation more accurate. You may have to slightly adjust the tuning pegs and/or the bridge saddle to get the string in tune when open and when fretted at the 12th fret.

This is a diagnostic procedure and temporary, but if it helps your tuning (which I am positive it will), then you may want to invest in a compensated nut. Earvana makes one that can be fit to your guitar without having to make any modifications to your guitar. And it also is completely reversible. They make another version which requires some modification to your nut slot which has a better result, in my opinion, but obviously it is not reversible.

Keep in mind that adjusting the intonation at the bridge has a greater affect on the tuning/intonation of the strings closer to the bridge and less toward the nut. This is why a compensated nut works so good...it's like putting a bridge at the nut as well...the nut has a greater affect on the strings closest to the nut and less toward the bridge while the bridge saddles have a greater affect on the strings closer to the bridge and less toward the nut. They work together.