Official Luthiers Forum!

Hi guys
I haven’t really done any of this yet, so the application is new to me. I have a guitar finished, it’s only been just done...
Sounds really nice
When I check intonation the top 3 strings are a tad sharp to my ear when fretted at the 12th.
The saddle is only rounded at the top, nothing is compensated.
So in theory I move the breakpoint back toward the end in order to combat this correct?
Do I basically use a flat file where the sting would be and slope it that direction?


Sent from my iPhone using Tapatalk

Yes, you move the break point back. You want to lengthen the string length between the 12th fret and saddle to make it play flatter.

And you can use a length of unwound low E string bent in an L shape and slide it under each string. Move it around while checking at the 12th and when it’s perfect mark the spot on the saddle with a pencil. Then take the saddle out and file to the lines at each string location.

I like this duck billed vise from SM to hold it while shaping - https://www.stewmac.com/luthier-tools-a ... -vise.html

If you don’t have the strobosoft app for your phone grab that. It’s nice for this and has a noise filter feature where it will filter the ambient noise in your space. This can help with keeping the measurement from jumping around.

Hope that helps.

Brad


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

You’re right about that vise. I have it, and it’s great!


Sent from my iPhone using Tapatalk

When you say, "the top 3 strings are a tad sharp to my ear when fretted at the 12th." Do you mean in comparison with the 12th fret harmonic?

When fretted at 12 and compared to the open string


Sent from my iPhone using Tapatalk

Ok so even doing that test has human factors problems but typically the test is play the 12th fret harmonic and let it ring then quickly play the 12th fret note and compare them. The human factors error of course is in how you play that 12th fret note. The harmonic is pretty much as accurate as you can get. You might be able to get a better strident sound when you pinch it right at the half way point but it's going to ring on a note. The problem is in fretting. I always try and use the lightest touch possible when fretting the string at the 12th fret to compare to the harmonic. If you press it too hard you will go sharp and think that your intonation is off but it's just becasue of your fretting pressure.

Fretting at the 12th and comparing the open string creates another variable in the equation. So try the harmonic test first and how does that come out?