Going Sharp

[Paul Hird]

Quick question for all you Luthier types. My intonation is pretty right on at the 12th fret. My question is, when I pick any open string and then start moving up the fretboard on any particular string, is it common for the note to be sharp as soon as I start moving up the first second third string etc.? Any comments?

Thanks!

[sblock]

I would first assume that your mandolin has a correctly made fretboard, with correct spacings. If all notes are sharp as soon as you start fretting them (on a low fret), and on all four strings, but they give the correct octave at the 12th fret, then the chances are pretty good that your nut is too high. As a result, pushing the string down the fretboard requires excessive displacement, and winds up stretching the strings, causing them to go sharp. The problem should diminish as you go farther up the fretboard.

If the nut is at the correct height, however, then your symptoms could be caused by a bad fretboard, with an incorrect distance between the nut and the first fret (too big). The would require surgery to shorten the top of the fretboard and replace the nut.

Finally, when you wrote that "my intonation is pretty (sic) right" at the 12th fret, is it truly right? Did you check it with a tuner?

[Greg Mirken]

If the 12th fret note is accurate but the notes at the first few frets are sharp [and get less so as you go up higher] either the strings are too high at the nut [likely] or the first fret space is too long [much less likely, but possible. I have corrected Gibson guitars with this problem.]

Greg Mirken

Rats, sblock beat me...

[Rob Meldrum]

I suggest you evaluate your current setup. Email me at rob.meldrum@gmail.com and put Mandolin Setup in the Subject line. I will email you my ebook on how to set up a mandolin. It's free. :-)

My guess is you'll find one or more of these three common issues: the nut slots are too high; the nut slots are not angled downward toward the tuning pegs; and, the strings are too high at the 12th fret. Once you correct all of these and you adjust the intonation I think you'll find the problem has been resolved.

Good luck!

Rob