Intonation question.

Quattroste

I have never bothered with intonation before but last night I restrung my Eggle and tuned it up. Then I though I try fretting the 12th and seeing if it was still in tune. All strings were slightly sharp. How do I go about fixing this? Is it bright height? Is it the little tuneomatic things in the bridge? Am I a stupid focker or what?

-=al=-

what bridge has it got? fixed bridge? strat style trem? Locking trem?

What you want to do for adjusting the intonation is adjust the saddles its pretty easy to do on fixed and fender type trems, u just arjust the screws behind the saddles accordingly,

I forget which way sharpens or flattens it but see whats what and fix it up.. if u adjust the action you'll have to re-intonate too....

Doctor J

Instrument resources sticky - setup guides.

Voodu Child

Also, i usually check by the twelfth fret harmonic, rather than by fretting it. It works out better that way, because, TBH, unless youve got a compensated nut (buzz feiten style), you are only going to be ever roughly in tune. USing the 12th fret harmonic will spread the error over all the neck, though some people use higher or lower frets to check intonation, (if for example theyre nu-metallers, who barre the first five frets and thats it...

Johnny Storm

I'm not clear what you mean there, voodoo_child? Are you comparing the harmonic at the 12th Fret to the fretted note at the 12th fret and adjusting the intonation to make them the same?

Doctor J

That's what I do, compare 12th fret harmonic with 12 fret and take it from there. Though if your open and 12th fret harmonic are different you're in a world of **** anyway and a trip to the guitar doctor is called for.

Johnny Storm

That's what I was thinking, Dr J. Because of those pesky ol' laws of physics AFAIK the harmonic at the 12th Fret must be the octave of the open note no matter what way the intonation is set. (I think?)
The only way they could be different is if the string was badly damaged ?

voxpop

yeah i thought it was open and 12th fret harmonic that should be the same. btw should they both be exactly the same i.e. is the intonation screwed if the open string is fine but the 12th fret harmonic is slightly flat or sharp ?

Johnny Storm

Angry_Penguin wrote:

yeah i thought it was open and 12th fret harmonic that should be the same. btw should they both be exactly the same i.e. is the intonation screwed if the open string is fine but the 12th fret harmonic is slightly flat or sharp ?

Do you mean the 12th fret harmonic is slightly flat or sharp compared to the open string? In that case I think you need new strings.
If you mean 12th fret harmonic is slightly flat or sharp compared to the fretted 12th fret than you need to adjust your intonation.

PS - I dont really know what I'm talking about

Doctor J

Johnny Storm wrote:

That's what I was thinking, Dr J. Because of those pesky ol' laws of physics AFAIK the harmonic at the 12th Fret must be the octave of the open note no matter what way the intonation is set. (I think?)
The only way they could be different is if the string was badly damaged ?

That or possibly if the pickup magnets are pulling the string but either way you're toying with the laws of physics

Quattroste

Bridge is Gibson LP style... can't remember the name though. I'll try adjusting screws to see what happens.

Thanks.

Doctor J wrote:

Instrument resources sticky - setup guides.

What I am saying is that I didn't really want to search throught the entire setup guides and confuse myself as I am not too pushed anyway, but what I want to say is... don't be so anal Doc!!

Voodu Child

voodoo_child wrote:

Also, i usually check by the twelfth fret harmonic, rather than by fretting it. It works out better that way, because, TBH, unless youve got a compensated nut (buzz feiten style), you are only going to be ever roughly in tune. USing the 12th fret harmonic will spread the error over all the neck, though some people use higher or lower frets to check intonation, (if for example theyre nu-metallers, who barre the first five frets and thats it...

What I should have said was check the 12th fret harmonic rather than JUST by fretting it. Anyway, its not rocket science, and also its not 'anal'. Setting you guitar up properly is something every guitarist should learn to do, because the results are well worth it, and also because 99% of guitar shops out there will just take a guitar out of the box and tune it. Maybe PRS's or whatever will get a proper set up, but most guitars wont. So however good or acceptable you think your guitar is, it can often be even better...

Johnny Storm

Quattroste wrote:

Bridge is Gibson LP style... can't remember the name though. I'll try adjusting screws to see what happens.

Thanks.



What I am saying is that I didn't really want to search throught the entire setup guides and confuse myself as I am not too pushed anyway, but what I want to say is... don't be so anal Doc!!

Here ya go, ya lazy so'n'so!
FYI some Gibson Tune-O-Matic bridges have the screws on the other side from the one in the photo - AFAIK this doesn't make any difference

Doctor J

Quattroste wrote:

What I am saying is that I didn't really want to search throught the entire setup guides and confuse myself as I am not too pushed anyway, but what I want to say is... don't be so anal Doc!!

OK, let me rephrase, there isn't anything most of us can say which isn't explained better (and with photos) in the links in the instrument resources sticky.

You haven't seen me being anal

sei046

oh god he said it....