SG intonation issues

[devilfish]

Hey,

I'm currently taking a luthier course which has basically made me acquire the need for my electrics to be set up perfectly. We won't be touching set ups til way later in the year/next year so I'm just after a bit of advice.

I have a Tokai SG that has a few intonation troubles.. if I tune the 12th fret harmonic/Open string then compare to the 12th fret fretted note, all strings intonate pretty damn close to perfect.

However, on the treble strings, specifically the G string.. the lower fretted notes (1-5) are significantly sharp.. I've adjusted the bridge saddle back and forth but it seems to make very little difference to the fretted notes if anything at all!

Can someone suggest things to try? I'm aware it could be fret/nut/bridge related but can someone suggest what the actual problem could be and why it would cause this king of problem?

Thanks!

 

[Kam]

Re: SG intonation issues

If it's the lower frets then I'd say it's almost definitely the nut. It's probably too high and needs to be filed down. Dan Erlewine has a really good chapter on this in his book, if you have it. If not then I'm sure there's any number of good tutorials for properly measuring nut height all over the web.

 

[David Collins]

Re: SG intonation issues

The vast majority of sharpening problems in the first frets are caused simply by the nut slots not being cut to the proper height. Sometimes the slots are not clean or at the right angle, sometimes the nut is just in the wrong place, but most of the time it's simply the strings not set to their proper height by the nut.

Moving the saddle is not typically a solution here, as ever cent you flatten a lower fret by this means will have twice the effect on the octave above. Sometimes a modest amount of compensation at the nut can be in order, but this should only be done after you are certain it has been cut to proper string heights.

 

[devilfish]

Re: SG intonation issues

By compensation at the nut, do you mean removing material where the string meets the nut, in effect adding string length to that particular string?

Thanks guys. I'll take a look and measure it as accurately as possible for the "correct string height. If not I'll deepend the slots/clean them up and try setting the guitar up again without string buzz. The action is fine to play for me, Just obviously not right if the intonation's outta whack!

 

[David Collins]

Re: SG intonation issues

By compensation at the nut, do you mean removing material where the string meets the nut, in effect adding string length to that particular string?

Opposite. To increase nut compensation means bringing the nut toward the frets, sometimes by cutting material from the end of the fingerboard, or more often done today by extending a shelf section of the nut over the end of the fingerboard. This involves making a new nut, or at least adding an extension shelf to the existing one and re-cutting the slots. This should not be a first course of action in my opinion however, as it does not come without consequences on intonation elsewhere along the board.

First step is making sure the string height is proper, and that the slots are not cut at a poor angle that leaves them departing from somewhere before the face of the nut (effectively resulting in a reverse compensation).