I'm puzzled. . .

Paul_C

. . . not for the first time, but this is very odd.

A customer dropped off an Ibanez Artist today with tuning issues. It has previously had a new nut fitted which wasn't great and I replaced it.

Tuned up and intonated it sounded fine apart from the low string - playing an open G chord the low G sounded horrible and read sharp on my tuner (Peterson VS-II).

I stuck a wooden toothpick under the string to see if the nut position was at fault and finally managed to get the open string, 12th fret and G on the third fret all in tune, but the toothpick is 6mm from the edge of the nut !

The frets are pretty worn but I have tidied up the shape of the fret in the problem area so I wouldn't expect its impact to be massive - but I'm not sure what else it can be.

I fitted a new set of EB 9-42s and have replaced the bottom string with a new one just in case, but nothing has changed.

Any thoughts ?

WezV

tune it so a fretted note is in tune.  try the dodgy note first and compare to the open string.   then try it tuned 5th or 12th and compare to the open string too

you should be able to narrow it down to a specific location

Paul_C

It's not just the G, it's the frets at the nut end of the neck

with the new nut in the "right" place and the guitar intonated the error is getting progressively less the closer to the 12th fret.

with the toothpick at 6mm away from the face of the nut the notes at the nut end are all pretty much in tune.

WezV

well I like a bit of nut end compensation, but 6mm is taking the piss

I can see why you are puzzled??  any pics?   

Is it just the one string affected then or are all improved by some compensation?

I would be working through some of the early steps in this to check fret/nut positions

http://www.mimf.com/nutcomp/

Nomad

Only on one string? The low E?

Paul_C

the low E is by far the worst but there's a hint on the other wound strings

steamabacus

Could it possibly be some kind of resonance issue? Does it show the same behaviour tuned to Eb or D even?

Nomad

How high is the action at the nut?

How do the break angles over the nut and saddles look?

Do the saddles have a normal looking pattern of distances from the nut, or are any out of the expected position relative to the others?

Paul_C

I replaced the nut (I have been doing such things professionally for 13 years ) and the height is fine as is the break angle.

I have set up hundreds of guitars but I don't think I know all there is to know, otherwise I'd have kept my head down

I'm going to double check everything in the morning, including checking the fret positions against the scale length and putting another string on just in case something weird has happened with both strings, but don't forget the owner said he's always had problems with it since a friend gave it to him so there may be something odd/wrong that's always been there. 

underdog

Is it just the wrong scale length neck or something? It's seems incredibly odd.

Paul_C

underdog said:

Is it just the wrong scale length neck or something? It's seems incredibly odd.

this is why I asked for suggestions

I've replaced loads of nuts and done hundreds of set ups but just once in a while something comes along to make you go - huh?

Roland

Is the bridge in the right position?

WezV said:

well I like a bit of nut end compensation, but 6mm is taking the piss

How much would you use?

WezV

A smidge.

0.5mm works well without going down the fully compensated nut route.

On this one the guitar previously had a replacement nut, suggesting the issue has always been there, or a weird nut was taken out and replaced with a standard one

stickyfiddle

Wondering if it has previously been Buzz-Feiten-ed and then un-Buzz-Feiten-ed without putting the nut in the right place?

GuitarMonkey

It's got to be the strings. I've seen something similar with Ernie Balls where the windings were uneven and I just couldn't get a guitar to intonate.

Andyjr1515

Hi @Paul_C Are you talking Open G tuning, or playing G in its lowest position? Either way, I'm inclined towards @GuitarMonkey 's view that it is the string ( I was once asked to move someone's acoustic bridge by an experienced player by about 5mm forwards! I changed the strings to a different make and it intonated perfectly). However, there is something odd about the low 'E' string on many guitars (been playing since I was 14 and now 61) I routinely de tune the low E by a couple of tuner degrees to make it sound right up the scale on the majority of my guitars. Again, this is nothing to do with the nut. To be honest, I thought everyone did...

JimSoft

Did you get anywhere trying to resolve this?

Paul_C

I'm still working on it ( stopped for a while to re-string my uke bass and play with my daughter) and I've managed to improve it quite a bit.

I didn't quote for a lot of fret work but having checked the scale length and the first few fret positions it all appeared to be spot on, so I reshaped the first eight frets (they have some visible wear but not big divots) to see how a more defined radius would change things and a quick look before I had to break for dog-walking and daughter-watching showed a big improvement.

I might still have to add a little material to the front face of the nut if I want to get things spot on but it's already much better.

Paul_C

All sorted

The problem does seem to have been due to the excessive flatness of the wide frets, my initial bit of exploratory filing obviously had little effect as when I did it properly - taking all the strings off, covering the top of the fret in black marker and rounding over until there was just a hint of a line in the middle (which is what I'd normally do after leveling worn frets) then polishing them up.

It just goes to show that sometimes deciding that "they don't look too bad" can be a dangerous thing to do, and it doesn't hurt to be reminded of such things once in a while