Tuning problem on new uke

[Quinny]

Hi
I have just finished building a concert sized uke. Problem is when I tune the open strings, the frettied notes are sharp. A few are quite sharp according to the electronic tuner. I then tuned it so that first fret notes were in tune. All other fretted notes were then also in tune. So I assumed that the problem is either with the first fret or the nut.

My string slots were a bit deep so I wondered if they were catching on the side of the slots. So I made sure the angle of the slots was angled down low. I also splayed out the back of the slot to ensure the first point of contact was clean. It seemed to make some difference but I cannot say it was conclusive. I thought the nut may be the problem as the thicker middle strings gave me more problem, but Overall I wasn't that satisfied so I remade a new nut. Same problem.

I had already remeasured the scale length - 190.5mm to the 12th fret - and the fret positions. It appears that the first fret may be 1mm too long, should be 21.4mm.

Before I go filing 1mm off the end of the fretboard to shorten the first fret, does anyone have any recommendations or see what may be going on?

Thanks

Andrew

[simso]

It sounds like the bridge / saddle is in the wrong positIon, what's your tuning on the 12th for each open string

[Trevor Gore]

What you describe, Andrew, is pretty much situation normal. It's fixed by using nut compensation. If your nut to first fret distance is incorrect and is too long, it will make matters worse. Even if the nut to first fret distance is correct, that sharpening effect is still there. It happens because saddle compensation is added to make fretted notes play in tune. But the compensation is not needed on the open string, because it isn't fretted, so the extra string length makes the open string play flat. BUT, everyone tunes the open strings true, which makes all the fretted notes play sharp, more so toward the nut, until the effect washes out at the 12th fret, where saddle compensation has been used to make the 12th fret play true. Shortening the open string by moving the nut closer to fret 1 fixes things. How much to move the nut can get pretty complicated to work out (it's different for each string if you do it properly). There's a whole section in the book on various ways to do nut compensation to get a better result. I don't build ukes, so I can't give you any rough and ready numbers to try.

Welcome to the intonation nightmare!

[Quinny]

Thanks for the detailed reply Trevor. I have been told a few times that nylon stringed ukes don't need saddle compensation. The tuning worked out fine on my tenor uke, however what you describe in detail makes sense as to what is happening on my concert uke.

You mentioned compensation at the nut, or did you mean compensation at the saddle? which I have read about?
If indeed you meant nut compensations for each string, does that mean cutting the string slots differently for each one?

Thanks

Andrew

[Quinny]

Hi Steve, thanks for your reply. Just to clarify, are you asking to check tuning with the 12th fret pressed or open string at the 12th fret position??

Andrew

[Trevor Gore]

You mentioned compensation at the nut, or did you mean compensation at the saddle? which I have read about?
If indeed you meant nut compensations for each string, does that mean cutting the string slots differently for each one?

Nut compensation like this and saddle compensation like this. These are steel string guitar examples but classical guitars get a similar treatment.

I have been told a few times that nylon stringed ukes don't need saddle compensation.

I'm surprised that you can get away with no compensation on a uke, but the uke experts will no doubt tell you what they do.

[Allen]

It really depends on the string choice, scale length and action on the amount of compensation. Some require very little on the e string and lots on the C and low G, and others are pretty even on across all the strings as far as the amount required.

Part of the "charm" and indeed part of the "Hawaiian" sound of the uke is that there is expected to some little bit of dissonance, with it being a folk instrument. The advent of electronic tuners has many people checking each and every note and expecting them to be spot on to the last cent, which is never going to happen.

I can see some string brands change over a week and even less in some cases with their intonation. I've caught myself a couple of times thinking I've stuffed up something because the intonation is so off. Checking things out many times to make sure, only to change the string to some fresh ones of the same brand and all is sweet.

Andrews issue seems to stem from less than perfect execution. Sure it's disappointing, but it happens. Especially when you are just starting out.

But take heart. I've had several quite expensive "Pro" built instrument brought to me to remedy bridges glued in totally the wrong location. One so bad that you'd have to be completely tone deaf to play past the third fret it went so sharp.

[Quinny]

Thanks for the input guys. I'm just a little unclear on why you would compensate the saddle versus the nut. I tried to do Internet research but haven't found anything too clear yet.

[simso]

Without having the instrument in front of me, I'm trying to establish a starting point.

When the open string is tuned exactly to pitch, what is the tuner display on the fretted 12th note, is it exactly the same, sharp or flat or different note all together,

From this we can work up to the nut and down to the saddle to establish where your problem lies

Steve

[Quinny]

Steve, at the 12th fret all notes are mildly sharp, but the C string is moderately sharp.
One thing that confuses me is why you have to compensate both the bridge and the nut.

Thanks
Andrew

[simso]

Don't worry about that part at the momment.

Let's deal with the first issue, being mildly sharp on the 12th when fretted needs to be addressed before addressing sharpness on the other frets

The good thing is your scale length was close enough, wanted to make sure you didn't use the wrong scale length to start with.

First tweak your saddle so 12th is as perfect as you can get to the open string

And yes ukes are generally sharp between the nut and 12th, but let's fix one issue at a time

Steve

[Trevor Gore]

One thing that confuses me is why you have to compensate both the bridge and the nut.

To avoid the problems you're having.

The short explanation is back here.

If you want more explanation, google "Nut Compensation", but not many of those explanations are correct and will likely confuse you more.

If you want the full, real, story with all the charts and maths, there's 25 pages on it in the book. (Section 4.7), written with specific reference to guitars, of course, but the same physics applies to ukes, too.

[mickeyj4j]

If you want the full, real, story with all the charts and maths, there's 25 pages on it in the book. (Section 4.7), written with specific reference to guitars, of course, but the same physics applies to ukes, too.

What is the book mentioned here.

[kiwigeo]

If you want the full, real, story with all the charts and maths, there's 25 pages on it in the book. (Section 4.7), written with specific reference to guitars, of course, but the same physics applies to ukes, too.

What is the book mentioned here.

http://www.giletguitars.com.au/book.shtml

More commonly known as "The Books".

[jeffhigh]

If the distance to your first fret is too long by 1mm, that is the first thing you should fix, and you may then need to do nothing more.

[simso]

But how does he know that its too long to start with, thats why we always do an open string and then half its length, this is your base line

[jeffhigh]

In the first post the Op says he has measured the first fret position and it is too long by 1mm. It will never play in tune till that is corrected.

[simso]

Mmm, I see and repair instruments, so for me I look at things differently to most others. As a builder you may have a certain way of viewing things, Im not saying this is right or wrong,

The op saids he has 190.5 at the 12th, so to me instantly that means he has a scale length of 15 inches. The 12th fret is in the right positiuon at 190.5 on a 15 inch scale length. If the scale length is 15 inches and the intonation at the 12th is wrong then I would address that issue first, to me its irrelevant if he has physically placed the first fret 1mm in the wrong spot. We can deal with that issue later, we need a starting point rather than just, lets trim the nut side of the board down and so forth. If the 12th fret is in the right spot then thats the important starting point for me,

Steve

If your interested, here is our facebook page of some of our fixups / alterations..

https://www.facebook.com/MusicalInstrum ... =bookmarks

[jeffhigh]

Hi
I have just finished building a concert sized uke. Problem is when I tune the open strings, the frettied notes are sharp. A few are quite sharp according to the electronic tuner. I then tuned it so that first fret notes were in tune. All other fretted notes were then also in tune. So I assumed that the problem is either with the first fret or the nut.

My string slots were a bit deep so I wondered if they were catching on the side of the slots. So I made sure the angle of the slots was angled down low. I also splayed out the back of the slot to ensure the first point of contact was clean. It seemed to make some difference but I cannot say it was conclusive. I thought the nut may be the problem as the thicker middle strings gave me more problem, but Overall I wasn't that satisfied so I remade a new nut. Same problem.

I had already remeasured the scale length - 190.5mm to the 12th fret - and the fret positions. It appears that the first fret may be 1mm too long, should be 21.4mm.

Before I go filing 1mm off the end of the fretboard to shorten the first fret, does anyone have any recommendations or see what may be going on?

Thanks

Andrew

Simso

I build and repair instruments too
If you read the OP fully you will see that Andrew has given us quite a lot of information. In particular he has already tried tuning at the first fret and found that when he did , all the fretted notes were in tune . This along with measuring the nut to first fret as being too long is a pretty good indication that shortening the fretboard at the nut will fix the problem.

[simso]

Have made many a compensated nut for a ukelele. I also make ukuleles and teach ukelele building, currently am doing a one on one build with a customer and have two ukuleles on the build.

But I call myself a repairer rather than a builder, as a builder I am very much a hobby builder, I'm not making hundreds of guitars or ukes a month. But I am repairing hundreds per month easily

I also happen to have 5 personal ukuleles, two of my own make, two lanikais and an ovation.

If I have a uke with perfect intonation on the open and 12th it will still be sharp on the nut side, i can also tune that perfect 12th ukelele so that the first fretted note is perfect, however as you play up neck it gets flatter and flatter until your a whole semi tone down by the 16th. So shortening the fretboard doesn't resolve this situation.

It's manipulating the scale either side of the 12th, via saddle and nut, always using the 12th as a reference point each time, you can end up with a very good response across all fretted positions without going overboard such as doing a true temperment fret job.

All of course how I approach it, not saying my way is the only way.

Steve

[Nick]

Hi
I have just finished building a concert sized uke. Problem is when I tune the open strings, the frettied notes are sharp. A few are quite sharp according to the electronic tuner. I then tuned it so that first fret notes were in tune. All other fretted notes were then also in tune. So I assumed that the problem is either with the first fret or the nut.

My string slots were a bit deep so I wondered if they were catching on the side of the slots. So I made sure the angle of the slots was angled down low. I also splayed out the back of the slot to ensure the first point of contact was clean. It seemed to make some difference but I cannot say it was conclusive. I thought the nut may be the problem as the thicker middle strings gave me more problem, but Overall I wasn't that satisfied so I remade a new nut. Same problem.

I had already remeasured the scale length - 190.5mm to the 12th fret - and the fret positions. It appears that the first fret may be 1mm too long, should be 21.4mm.

Before I go filing 1mm off the end of the fretboard to shorten the first fret, does anyone have any recommendations or see what may be going on?

Thanks

Andrew

Simso

I build and repair instruments too
If you read the OP fully you will see that Andrew has given us quite a lot of information. In particular he has already tried tuning at the first fret and found that when he did , all the fretted notes were in tune . This along with measuring the nut to first fret as being too long is a pretty good indication that shortening the fretboard at the nut will fix the problem.

By a process of elimination I would concur with Jeff, if everything plays 'in-tune' once tuned correctly from the first fretted note then that would tell me that, a) the frets are all placed at their correct distances from each other (after the first fret) but, b) the open string length is wrong. If they play intune up the fretboard from the first fret then the bridge must be in the right spot so it leaves only the nut and Quinny has already stated he's measured it as being too long a distance to the first fret.
One way you could tell quick and easy Quinny without any alterations to the Uke, is to cut a strip off an old credit card or other plastic card slightly wider than the distance from the board to the bottom of the string slots, most cards are usually 0.8mm thick, and slide it under the strings at the nut so that the strings are sitting on the edge of the plastic card. Retune and see how it plays up the board then, it won't be spot on because you still have that 0.2mm difference (unless you can find something that is 1mm thick to begin with!?) but it should get you closer if that's where the problem lies.

Another possibility to look at (not the only cause but one that could add to your problems and also to be aware of perhaps?) is the nut slot height, if the strings are sitting too high off the board then the strings will have to stretch further than they normally do, to hit the first few frets especially! Thus sharpening them more than normal, although they would gradually come back into tune as you fret higher up the neck.

[kiwigeo]

It would appear that not all posters in this thread are in tune with each other

[simso]

My comments are only coming from the fact I have never found a uke in tune, out of the hundreds if not dare I say thousand uke repairs, not one has been in tune across its whole range.

With compensated saddles and compensated nuts, they are much better IMO,

So I take comments that every note plays in tune when tuning the first fret with a grain of salt, not that I am trying to disparage the author. Hence why I always establish a base line, to that end it has taken me longer to type on this topic than it would have been for me to fix it, so enoughs enough.

We all have different defintiions of what is in tune, some may say up to 40 cents out is still in tune, I dis-agree

I will retire from this thread and watch with interest, I may at a later date post back in, on this one

Steve

[Quinny]

Wow. I had yesterday off work and did my experiments and adjustments on the uke. I didn't realise so much was happening on this topic! Thanks guys. Despite differing opinions, this has helped me reflect and stimulate my own questions and helped me understand the concept of intonation and compensation. The effective and practical solution was to put on softer strings to reduce string stiffness and trim the first fret by 1mm - a very acceptable result.

I managed to find one internet site that gave clear info on intonation and compensation - http://setitupbetter.com/Setup-Overview.php. This site also admits it approaches bridge conpensation differently to the norm. He sees the function of bridge conpensation to ensure all fretted notes are in tune with each other, and compensates the bridge only to ensure tuning between the 2nd and 14th fret. Then uses nut compnesation to tune open strings to fretted notes.

Anyway, my solution has been two-fold, with one new element to the intonation issue, that is, string stiffness.

I placed masking tape on the middle of the fret board and used a pen to mark the centre of the frets to get an accurate assessment of fret placement. It did confirm the first fret was 1mm too long. I did file it and when restrung and tuned the fretted notes were less sharp.

I had used D'addario Titanium strings to get a bright sound, but these ended up being really hard strings, even hard on the fingertips. So I put on Aquila Nylgut yesterday and there was already a lessening of sharpness again and a strong and clear sound and much easier to fret notes.

The fretted notes were still all in tune so I didn't do bridge compensation. I took the advice from the website and tuned the uke to the second fret, and then went about compensating the nut to get the open strings in tune. This required about 3mm of conpensation. Howver, as I played it last night it was way too hard to press the first fret as it was now shorter. It became impactical, even though every open string and fretted note were in tune.

So this morning I made another nut without compensation and sighed with relief as how easy it was to fret notes. I tuned it and checked sharpness of the frets and it was sharp to a very small degree. I put the former nut in with the 3mm shelf and did an experiment by filing off another mm to make it more playable. While it was easier to play, the 2mm nut compensation was no more in tune than no compensation at all and still made it harder to fret.

So in the end, softer strings and taking off the 1mm to correct the first fret worked. I could achieve spot-on tuning with nut compensation, but found it wasn't worth it by the effect it had on pressing the first fret. I take solace from Allans words: "Part of the "charm" and indeed part of the "Hawaiian" sound of the uke is that there is expected to some little bit of dissonance, with it being a folk instrument." This 'bit of dissonance' allows a good balance between 'perfect' tuning and easier playability.

Q: Does anyone who compensates the nut - and plays it as well - find that on an instrument as small as a a concert sized uke, it isn't practical as the first fret is so short it effectively makes it hard to press? Any experiences on this is appreciated.

Thanks to everyone who got into this thread. It has plunged me headlong into the challenges of intonation and helped my education and experience. It was a real challenge to get the optimal soultion but it was also fun!

Andrew

[kiwigeo]

Andrew, I still urge to you to read the relevant sections of Trevor and Gerard's "Books".......the theory is explained extremely well as well as different methods of intonating an instrument....with varying degrees of complexity and accuracy.