Problem with octave mandolin playing slightly out of tune

[Dave Reiner]

I have a 2 year old octave mandolin from a good builder. Sounds great but it doesn't always play in tune.

When I tune it carefully, the 12th fret harmonics seem fine, the 7th frets match the next higher string, and the 5th frets match the next lower string. Action is medium-low and the nut looks ok.

When an Am chord sounds good (2200), and a D chord also sounds good (2002), then a G chord sounds out of tune (0023). If I adjust the tuning to get the G chord in tune, the other chords go out slightly. Is this typical of octave mandolins, or is it more likely a problem with this one? Any recommendations?

Thanks,
Dave

[Phil Vinyard]

Had a similar problem with my octave. Finally gave up and took it to my favorite luthier who immediately saw the problem. The action was uneven at the nut and it caused lower frets to go sharp. I couldn't tell by looking, but he could and then fixed it. I encourage you to take your octave to a good luthier.

And by way of uncompensated, unsolicited plug: my favorite luthier is Matt Harmon at Mass Street Music in Lawrence, KS. A nice Missouri boy stuck in amongst the Jayhawks.

[foldedpath]

Are your strings new, or fairly new? Intonation problems accumulate over time, as the strings become gradually less uniform due to fret wear and stretching. It'll creep up on 'ya, sometimes happening even before the strings start to sound dead and in need of a change. Always debug tuning problems with new strings.

Also, have you checked that the bridge position is correct? Compare the fretted note at the 12th fret with the 12th fret harmonic, using a good electronic tuner. If the fretted note is flat, then move the bridge closer to the nut, and vice-versa. Check all 4 courses this way. You may not be able to get all four in perfect 12th fret intonation, but you should be able to get pretty close if the saddle compensation is good.

If that doesn't help, then I'd agree with Phil that it might be time to have a good tech look at it.

[Dave Reiner]

Thanks Phil. I had suspected the nut and will get it checked out. I'm 5 minutes from the Music Emporium in Lexington, MA, so I'll take it there rather than Kansas.

And thanks, foldedpath. Actually, the bridge position is correct by the harmonics, and the strings are relatively new.

Dave