B string too sharp at 3rd fret 🔪
 

I like to tune to octaves, and to check different strings against each other at both fretted and open octaves. On the second string, I find the 3rd fret D is 4 or 5 cents sharp against the open B. Some measurements on the B string:

Fret 1, +1
Fret 2, + 1.5
Fret 3, +4-5
Fret 5, +4
Fret 7, +1.5
Fret 12, +4

For comparison, the 1st string is within .5 cents on every fret against the open string.

The sharpness of the 3rd fret D is bothering me. What might be the cause and remedy? The nut slot seems low enough. Thanks for your insights.

Sharp on the lower frets usually indicates a nut issue...

Sharp all the way up is intonation in general...have you tried a compensated saddle? What kind of guitar are we talking about here?

It's a Blackbird Savoy, an 0-sized guitar made of a linen/resin material called ekoa. It has a man-made compensated saddle.

https://s17.postimg.org/kwhfn47lb/IMG_3008.jpg

This is a stupid question, but since this is a bit odd, I have to rule out everything...is the saddle installed backwards?

A reasonable question. But no, saddle is in correctly with the comp at the B string.

You need to compensate the saddle more. Lengthen the B string.

Fret positions are a compromise for comfort of manufacturing, so no fret truly sits where it needs to sit, we fit a flat piece of nickel silver under all 6 strings at the one location and expect it to play in tune for all 6 strings.

Provided, nut height is good, saddle height is good, relief is adjusted correctly, then we do the following.

Understanding fret positions are a compromise, we can adjust a few things around it, if the open string is to pitch "B", then the 12th fret position should also be a "B" exactly, if B is sharp when fretted then the saddle for B needs to go back towards the end of the guitar, if B is flat then the saddle needs to be moved towards the nut end of the guitar.

Once the saddle has been set correctly further adjustments can be made at the nut end.

We can tweak intonation and get very good improvements, but look up true temperament fretting system, this shows you how crazy the frets can get to achieve in tune.

Steve

http://www.mirwa.com.au/images/sx.JPG

Fret wear?

Those numbers look odd to me. I'd probably try a new b string before I went further.

Will try a new B string.

Doesn't seem likely. The guitar is less than a year old, and has stainless frets, and they look okay.

Yikes! Plus filler characters

It is still a compromise, just a different set of them.

I don't really expect to have every fret be perfect. This particular string/fret combo (B at 3, open D) just grabs my attention. Now I must go locate my snow shovel. Or an Ovation. :)

The b string should be about 1.5 mm longer that the g string, and about .5 mm longer than the e string. IMO, of course, but my tuner agrees.