Intonation problem on 1 string

[wingchun1976]

I'm having the exact same problem with my guitar which has an OFR bridge with Graphtech saddles. I cannot get the bass D string (I'm tuning down 1 step) to intonate... All other strings are fine... The problem string shows flat so I moved the saddle toward the bridge and rechecked and the tuner shows absolutely no change!!! I've moved the saddle about a quarter of an inch towards the nut with absolutely no change in intonation! As someone said in a previous post this is a physical impossibility because the D saddle is forward of the G saddle...I suspect that the core of the string is slipping through the winding...this is the only idea that I can dream of. I'd like to hear other peoples thoughts on that and also the idea of soldering the end of the string as a way of preventing the core moving inside the winding...

 

[tfarny]

I think the right advice has already been given - change your strings, put the saddle about where you know it's supposed to be, and check again. Strings are cheap.

 

[-CB-]

Some notes on intonation -

The NUT can be at fault.
The PICKUP can be pulling on the string magnetically.
The STRING can be at issue.
The SADDLE can be at issue.

I know my string nuts are set up correctly - I do them.  If they're off, they're off by a very small amount that only a stroboscope would be able to illustrate.  I cant play all that well, so... who gives a flying (git)fiddle?  So, the intonation method I use, is to REALLY fine tune the open string.  I mean really really get it correct.  Then check it with a tuner, against itself at fret 5 (or 4 for the B string), fret 12, fret 17 (or 16 for the B string).  That will get me close.  Then you can tune the adjacent string, again, really really well... check its harmonic at fret 12.  Make sure that is perfect.  That is - dont check the fretted string, just the harmonic.  Then sound the harmonic, while fretting the string to be adjusted at fret 17 (or 16) and adjust the saddle so you get "zero beats".  Go back and recheck the "reference string" and its harmonic, and recheck for zero beat at the high fret on the string to be adjusted.  A guitar is a compromise anyway, so doing the intonation that way is really pretty much as good as it gets, unless you go for very sophisticated testing and equipment.

If the nut is off... that will throw you off big time. 

String windings that move, or are worn, will throw you off.

Excessively high (or low) string elevation in comparison to the other strings, will toss you out the window.

Bad break on the saddle... same thing.

 

[Schlieren]

So if the open tuning is right on and the first harmonic is not, that is a nut issue, is what you expressed?

 

[-CB-]

I go thru Fender 150 sets by the case.

Maybe you should try a different brand of strings?  :help:

HA!~~  I generally restring all the guitars I've played about every two months, plus the ones I've played a lot, maybe every two weeks.  Fresh strings, no matter the brand, just have that "snap".

 

[Super Turbo Deluxe Custom]

The tuner may be a contributor as well.  Of the three I have, 2 are ball park and 1 is so accurate you would have to have a 100 to 1 gear ratio on the tuning machines to ever get it perfect.  In the end, close is good enough and I always go with what my ears tell me.  A 12th fretted note and harmonic can read dead on on the tuner but not sound right sometimes.

 

[wingchun1976]

The tuner may be a contributor as well.  Of the three I have, 2 are ball park and 1 is so accurate you would have to have a 100 to 1 gear ratio on the tuning machines to ever get it perfect.  In the end, close is good enough and I always go with what my ears tell me.  A 12th fretted note and harmonic can read dead on on the tuner but not sound right sometimes.

I have a Boss TU-15 which I feel is accurate. At any rate my ear agrees with the tuner, the fretted 12th is definitely flat when compared to the harmonic...the search goes on    :icon_scratch:

 

[wingchun1976]

If the nut is off... that will throw you off big time. 

String windings that move, or are worn, will throw you off.

Excessively high (or low) string elevation in comparison to the other strings, will toss you out the window.

Bad break on the saddle... same thing.

Hi CB. As far as the nut is concerned I can only guess that it might cause problems if it was out of square with the frets / bridge???
The core moving inside the windings is my current suspision...
The elevation of the string is not unusual...the radius of the strings at the saddle is just over 16" to match the Warmoth compound radius.
Can you please elaborate on what could possibly be wrong with the saddle to cause this problem...I can't guess what that might be as, unless I'm off track, I believe the critical value is the position of the saddle in relation to the nut / frets. Since this can only alter if you loosen the adjustment screw surely the saddle can't be at fault? Even if the saddle was manufactured incorrectly, unless it is able to move of its own accord, I can't see how a position could not be found that would yield correct intonation...    ???  :icon_scratch:

 

[-CB-]

As far as the nut is concerned I can only guess that it might cause problems if it was out of square with the frets / bridge???

Squareness matters, but what also matters is the place it "breaks", which must be the very front of the nut - the front being the side on the fretboard.  Nuts are usually cut with two angles.  One is the break angle, the other is a relief angle. If you imagine looking at the nut from the side, so the "face" of it (fretboard side) is straight up pointing at 12noon, then imagine the break angle being formed by the big hand just shy of 9 (on the 8 side of 9 on the clock dial).  Just a little angle, so the string has a good break point. Leaving about half the width of the nut's break angle untouched, a relief angle is then put in the slot.  That would be the big hand being more 8 on the clock dial, and its to make sure you have good tension at and over the break angle of the nut.

Can you please elaborate on what could possibly be wrong with the saddle to cause this problem...

Bad break angle, the breaking point on the saddle being mushy, poorly cut or fit.  This happens on TOM's more than anything, hardly ever on a Tele, and almost never on a "vintage" style Strat.  But... you have a non standard bridge, so inspeact the saddle closely as compared with the rest.

Another possibility is a nut loose performing the intonation.

 

[wingchun1976]

Solved!   :cool01:

As I suspected, somehow the windings were moving on the core and throwing the intonation off... I changed strings and this time I bared the core back about 3mm and bent it over on itself. Now the intonation is perfect! The strings I use are DR Alexi signature series that have round cores as opposed to hex, so maybe that is what makes them prone to this problem...anyway hopefully this info might help someone else along the way.   ccasion14:

 

[-CB-]

So if the open tuning is right on and the first harmonic is not, that is a nut issue, is what you expressed?

No.  The string and its harmonic will always be ok, thats physics... well... sort of, since harmonics are "off" by some small amount anyway.

What I'm saying is, your relationship from open string to any fret will be off, if the nut is off.....so before you use an open string and its fretted notes as a reference, make sure the nut is set up correctly, so the string breaks off the very edge of the nut.

If you use the 12th fret harmonic, against an adjacent string's corresponding fretted note, that should be ok, regardless of nut setup... but...why?  All that fiddling and not have a good nut... you're chasing your tail on things.