#1
hi guys

i got some guitars for free that need work, rewiring, cosmetic work etc..

i've noticed on a couple that the set up is a little bit out. i'll have it in tune and then check the 12th fret harmonic and that will be right but then when i check the frets they are badly out of tune (1/2 a semitone or sometimes more)

is this in need of a truss rod adjustment as it happens on every string
#2
The truss rod has absolutely nothing to do with intonation.

If the poor intonation occurs on the higher frets, that would be evidence that your action is simply too high. With action of any height, fretting the string to a fret induces additional tension to the string, causing the string to go sharp. Because of this phenomena, no guitar can perfectly intonate, but having higher action aggravates the issue.
#3
The 12th fret harmonic is always an exactly octave different from the open string regardless of set up. If intonation is bad, set the neck relief first, then the action height, then the saddle position/string length. The depth of the nut slots might also need altering, and I would do this after action height.
#4
ok thanks for the replies, so its more likely the bridge at fault with it happening around the 3rd fret onwards?
#5
Quote by the_origin
ok thanks for the replies, so its more likely the bridge at fault with it happening around the 3rd fret onwards?


I would check neck relief first. Get it up to pitch, then press the string down at the 1st and heel frets. There should be a gap about the thickness of a business card between the string and the 6th fret. I do that on the 1st and 6th strings.
#6
thanks guys. can't believe it was that easy of a fix. everywhere else was telling me that it was a truss rod problem and setting the action worked
#9
thanks with it being my first time doing it properly I'm going to get everything working then i'll think of modding the wiring and stuff