Simple question, tuning the nut on a soprano :confused:

Hello, a simple question; do you tune the nut?
I can´t seem to get it right?
What is the principle, please?
How should I think, please?
Regards

Never heard of tuning the nut.

Since the uke is a small instrument, tuning the nut compensation is a waste of time. Even on full scale guitars, a compensated nut works to a degree, until you start playing with other guitars, in which case, yours may play out of tune compared to the others. I would just make the nut straight, no compensation.

Henning said:

Hello, a simple question; do you tune the nut?
I can´t seem to get it right?
What is the principle, please?
How should I think, please?
Regards

Click to expand...

I am guessing your terminology is slightly askew or you just have a badly adjusted nut.
First thing to check is that it is properly seated with no extraneous gap underneath it or between the nut and the fretboard and that it is firmly in place.
Next adjust the action. A set of needle files or a hacksaw blade can take care of that. I use both. If you press your finger between the 2nd and 3rd frets you will see if there is a gap between the first fret and the string. The old timey method was to aim for a cigarette paper thickness.
If you take off too much back fill with superglue and baking soda.

Nut tuning I guess means nut compensation and it is an important issue to at least look at.
First things first. Is the nut precisely in the Right place. If the nut isn't ever so spot on in the right place you will have intonation issues.

Principles. The centre/highest point of the 12th fret is the zero,zero point for making all measurements. If the nut contact point is further away from the 12th fret than it should be then the intonation over the first few frets will go sharp. If the nut contact point is closer to the centre of the 12th fret than it should be then the intonation will go flat over the first few frets.

The distance from nut face/contact point to the centre of the 12th fret should be precisely half of the nominal scale length. Ie, nominal scale length is 17" then nut to centre 12th fret should be PRECISELY 8 1/2".

Nut and saddle placements work together and effect each other. Actual scale length is the nominal scale length (say17") plus some extra length at the SADDLE which is called the saddle compensation.
If the NUT placement is spot on then your 95% of the way there yet errors in nut placement is common. Now if you really want to be spot on and compensate the nut placement then the usual issue is that there can be a tiny bit of sharpness over the first few frets anyway so placing the nut a tiny bit closer (1mm is more than enough) to the centre of the 12th fret and then fine tuning by filing the contact point back slowly to fine tune so that its not all flat.

Measuring to make sure the nut is spot on and adjusting it if it isn't is 95% of the job done.

If I follow this procedure (yes, but of course ´compensation of the nut´ is the purpose or goal to reach for). If I do like this then
Tune the instrument on the 3rd and 4th frets then compare to the intonation at the nut. If the tone at the nut is sharp I file the resting point of the string at the nut upwards towards the head. If the tone at the nut is low compared to tone at the 3rd and 4th frets I´ll add material to the nut, making the string rest (at the nut) closer to the 12th fret (in the direction towards the saddle, ~1 mm or less), is that correct, please?

Hennng, by TUNING at the 3rd and 4th frets you've just added an extra step of complexity and reversed the whole deal.

TUNE the open strings. Then fret notes up the neck and record if they are going sharp or flat over the first few frets. If the notes are going sharp up the neck then the point where the strings exit the nut slot needs to be closer to the 12th fret. If the fretted notes are going flat as you fret up the neck then you file the contact point away from the 12th fret and towards the head.

OK, Now let me reverse it all. Lets say that the instrument is well intonated on all frets from the first fret up if you tune it so that the first fret is in tune and then just the open strings are out of tune.
If the OPEN strings are sharp, then NOMINALLY, we would say that the intonation is GOING FLAT and this is because the nut is too close to the 12th fret so you would file it back towards the head. If the OPEN strings are going flat compared to the fretted notes then nominally the intonation is going SHARP and you would move the nut contact towards the 12th fret by filing the end of the fretboard back or placing a shim on the fretboard.

TO be honest you need to be careful about reverse thinking until you have your head around it although I can see that it could be useful to reverse think it.
Stick with tuning the open strings first and then assessing if its going sharp or flat.
Also and importantly. Measure! And then measure again.
If the intonation is going sharp then measure where the nut is placed in reference to the 12th fret. If the intonation is going flat then where is the nut placed. If the intonation is spot on then where is the nut placed compared to the 12th fret.

The first step. Is the Nut placed PRECISELY where it should be?
If it is then good and what is the intonation like over the first few frets.
If its not precisely in the right place then adjust it but first measure what the intonation is doing.

The aim here is for you to know whats going on and place the nut exactly where you know it will need to be.

The nut. What's the 'right' place? It's theoretical position in respect of the rule of 18 or a touch forward? They can't both be right. . . . except that they can. One is in it's theoretical position and perfectly OK for the vast, vast majority of players. The other is compensated. If it's in the correct theoretical position you can add/glue a veneer (even bone) on the front of your existing nut but above the level of the freboard. It creates a step. Cut the string grooves into it. It only needs to be 0.5 mm. That is what some makers of guitars do, shorten the fretboard by 0.5 mm from it's theoretical position. Adding the thin veneer effectively does the same thing. Don't like the results? remove the veneer and you are back to your original configuration.

To clarify. When I say place the nut precisely where its supposed to be I mean its theoretical position at exactly half the theoretical/nominal scale length from the centre of the 12th fret. 0.5mm closer to the 12th fret is enough compensation and like a blank saddle you can file it back if the intonation over the first few frets is going flat.

Procedure

Here´s a procedure https://www.youtube.com/watch?v=1dxSv4cazEI
I find it to be useful.

Regards

Henning said:

Here´s a procedure https://www.youtube.com/watch?v=1dxSv4cazEI
I find it to be useful.

Regards

Click to expand...

An interesting video but so you know its aimed at a steel strung 6 string guitar.
A basic principle here is that the more flexible a string is the less compensation in needs and the less flexible a string is then the more compensation it needs.
Nylon/classic type strings don't need anything like as much compensation as steel strings do.
0.5mm nut compensation will be enough on a ukulele so making a gauge like in the video will be completely impractical.

Ensuring that the nut is placed exactly where theory dictates is 95% of the job. Adding a 0.5mm shim and filing it back if the intonation is going flat is the next 5%.
If/when you start measuring for errors in nut placement you will find its a common problem.
So first things first. Measure the nut placement from the centre of the 12th fret and is it where its supposed to be.