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the distance from my nut & the first fret is short by .025. So the 2 solutions I have conjured up are: glue in a .025 sliver on the end of the fingerboard,which will show somewhat or cut a rebate in the nut itself so the front edge is set back by .025.
Any ideas appreciated.
Mike McNerney, Ottawa

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Mike McNerney

I shorten the distance from the nut to the first fret on my guitars by adout .018 to .020. It helps the guitar play in tune on the lower frets. I think you will be allright just the way it is, you have to make sure that you compensate for it when you place your bridge and saddle. You have to maintain your scale length so make sure you measure from .025 past the nut or measure your scale length from the twelfth fret.

I comp mine by 40 thou (1mm), so you have nothing to worry about IMO. Its pretty easy to move it back if you need to, by angling the nut front edge .. moving one forward is a bit tougher !!!

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

.025" nut compensation should be just fine, and I wouldn't bother doing anything to correct it. You should however, move your bridge forward by the same amount if you want to intonate at 0¢ at the 12th fret. This compensation will offer ⁻1.6¢ change at the first fret (relative to a standard non-compensated board), steadily decreasing to no change at the 12th fret, and continuing that upward line to ⁺2¢ by the 20th fret. In practice, this can work out just fine.

If you were to maintain your saddle position as though the nut were not compensated, this would work out to flattening each fret from beginning to end by about 3.4¢ (relative to where a standard layout would put you.)

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Eschew obfuscation, espouse elucidation.

I wouldn't move the saddle. Your saddle is located in relation to all the frets, your scale length plus compensation, anytime you fret a note the nut is taken out of the equation, by moving the saddle forward by .025 any note you fret will be sharper. By moving the nut forward only the open string is affected shortening its length making it sharper by a little bit at the 12TH fret harmonic but has no affect on the 12TH fret note. The reason for moving the nut forward a little bit is to help out the open chords, who hasn't tuned up a guitar played a G chord then an open E chord and they sound out of tune, moving the nut forward helps them sound more in tune. I like to use 25" scale on my guitars so with your nut being .025 short, if I was to measure from your nut I would measure 24.975" then add my compensation. Theoretically my scale length is still 25", if you measure from the 12TH fret to my saddle you will get 12 1/2" (plus compensation) I wouldn't change that, it's where it should be.

This is a rather convoluted concept to wrap your mind around, but that's not quite true. Fretted notes relative to each other will remain unchanged if you compensate the nut without moving the saddle. Relative to the open string however, everything will change. If you intonate at the 12th to 0¢ offset and then compensate the nut .025" forward without adjusting the saddle in by that same amount, your 12th fretted note will be 3.4 cents flat relative to the open string - you would have to move the saddle .025" toward the board to bring it back to 0.

Every other note is effected as well. In this case, if your first fret was previously 2¢ sharp, now it will be 1.4¢ flat. If your 5th fret was perfect, now it will be 3.4 cents flat (relative to the open string). If you're playing closed chords or with a capo, this is no big deal, but it could certainly have an audible effect on any note past the 3rd fret played against an open string, especially if you happen to find a major sixth or minor third interval between them.

On the other hand, if you have a .025" nut and move the saddle forward by the same amount, you will find only a ⁻1.6¢ difference at the first fret, ⁻1.5¢ at the 2nd, ⁻1.4¢ at the third, etc, etc, no change at the 12th, ⁺0.7¢ at the 15th, ⁺1.2¢ at the 17th, up to ⁺2.0¢ at the 20th.

All these numbers do not indicate the absolute pitch of each fret, but rather the difference that would result from compensated vs non-compensated nut, if we assume all setup, strings, player consistency, cosmic alignment, etc. were to remain identical.

When you compensate the nut, you are essentially changing the scale length - or at least changing it according to 2 of the 3 main definitions often applied to the term. And it does most certainly effect every note on the board relative to the open strings and harmonics.

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Eschew obfuscation, espouse elucidation.

David - by compensating both nut and saddle inward by 0.025" - are you moving forward a saddle that is parallel to the frets? Or moving forward a saddle already compensated by tilting it in the usual way?

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The member formerly known as erikbojerik....

What your saying is to have the nut short .025 and the saddle short .025 for a total of .050

Erik - what I mean is moving the entire bridge, exactly as it would normally be laid out, but .025" toward the fingerboard. This means if you position your bridge by measuring nut to the 12th, multiply by 2, then adding .110" or whatever default compensation you use to position the bridge, you wouldn't change a thing from your normal procedure.

Mark - yes, that would indicate a total .050" shorting string length. By moving only the nut, you change the relation of every fret to the open string length, leaving a longer speaking length when considered as proportional to the open string. This effectively changes the open:fretted ratio by a constant amount, resulting in each note being flattened equally relative to the open pitch.

Compensate the saddle by the same amount, and the 12th fret ends up at the same open to fretted ratio as standard. The frets prior to the 12th will then have a diminishing change in the open:fretted ratio as you move upward, then increasing change in this ration as you continue upward beyond the 12th.

Here's how 24 frets on a 25" scale guitar would be different with a .025" compensated nut, and saddle adjusted forward the same.



Without moving the saddle accordingly, it would be ⁻3.4¢ change all the way across. Of course in reality it wouldn't end up this way, because as soon as you intonated the 12th fret to 0¢, you would end up exactly as the chart shows above. If you chose to intonate 1st to 13th, or 2nd to 14th, the line would end up somewhere between the ⁻3.4¢ line and this one, depending largely on how well your nut slots were cut.

Not moving the bridge would keep the relative pitch between different fretted notes constant, but change them noticeably in relation to the open string. Moving the saddle forward the same amount as the nut will change the relative pitch between fretted notes, but not noticeably over the length your fingers can stretch. Even with two handed fretting the differences between the fretted notes would be less than the differences between fretted and open would deliver in non-adjusted saddle method. More importantly it puts the largest realized compensation in the lowest frets where it is often needed most, and keep the 12th fret region still in better agreement with the open strings.

In reality, this is just a huge grey area with a near infinite range of subcategories of approaches. In the hands of a good player, most of them will work just fine in actual use of the instrument (playing a song rather than staring at the strobe tuner). In the end it all comes down to tweaking it according to real observations on the actual instrument. We're talking about a difference of .025" in saddle position here, and chances are that you'll have room to complete that tweaking just fine either way.

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Eschew obfuscation, espouse elucidation.

Thanks David!

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The member formerly known as erikbojerik....

I've finally taken to working on my book (Tuning, Intonation, and Temperament for Fretted Instruments) a bit more seriously lately. It will still be quite a while before I even think about going to a publisher, but I at least have developed some spreadsheets to lay out these charts a bit more easily.

I'll keep you posted, but don't hold your breath. The pace I tend to take things like this at means I'm probably looking at a few years before it's done.

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Eschew obfuscation, espouse elucidation.

David I'll take a copy!!!

Let me know when its in print! - this would be great - I also made that same 'error' on my first, was about 1mm short of full fret-nut distance for that scalelength, but followed the advice of the classical builder who mentors me and compensated the nut as well as the saddle and the intonation is pretty good at all frets with the exception of the 17th - which was put in the wrong position!

I've always comped the nut about .023 and set the bridge by marking the distance from the nut to the center of the 12th fret on a straight edge and setting that same distance plus about 0.12 comp to the center of the saddle in the midline. (1/8" setback angle from high to low E). Seems to work OK. Is this the same thing you are saying David?
Terry

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Thanks for sharing David! Jody

So is there a formula on how much a nut should be compensated? Well, besides Buzz Feiten's. Is there a rule of thumb? I figure it would all be dependent on what gauge strings and what the scale was. Those graphs look really interesting.

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John Thiessen
http://www.iszacguitars.com

I must bump this old post up just to thank David Collins for taking the time to write up the awesome posts in this thread regarding nut compensation. Thank you David.

By the way, any chance you've made any progress on your book David?

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Formerly known as Adaboy.......

BTW, does anyone have suggestions for nut compensation that works well on a long Martin scale (25.34") with medium strings? How about light strings?

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Formerly known as Adaboy.......

For the sake of discusion, and since intonation is a compromise , and there is probably no perfectly"right" way to do it . In Ervins book , he says he compensates the nut 1/16 which would be .0675, and says nothing about moving the saddle to compensate for moving the nut.but says compensating the moved nut is the answer. just tossing this out for discusion .. Jody

Mark, that seems the same method Mark described above (not sure if he used 1/16")..........and that is the method David addresses in great detail above.

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Formerly known as Adaboy.......

Thanks, David, for your contribution here. Good Stuff. And, sign me up for a copy of your tome (hopefully in only one volume).

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"Building guitars looks hard, but it's actually much harder than it looks." Tom Buck

Saddle is already commonly moved from ideal scale length to compensate the change in string tension when pushed on the frets. Nut compensation is done to compensate for lower fretted notes that otherwise would be flat.
Given the schema from David of how pitch of all frets would be with both nut and saddle compensation, wouldn't it be better to add compensation to fret scale instead than to the nut?

For example, we'd normally move the nut toward the first fret of about 0.4 mm. (just for example)
Wouldn't it be ideally better to move the first fret of 0.4mm toward the nut (uncompensated), and consequently all the frets from 2nd to 11th moving each one always a bit less (with 10th fractions of 0.4mm). Something like:
1st fret: original distance from nut less 0.4mm
2nd fret: original distance from nut less [0.4 - 0.04] mm
3rd fret: original distance from nut less [0.4 - 0.08] mm
...
...
11th fret: original distance from nut less [0.4 - 0.36] mm

This way lower fretted notes would be right at the pitch without making higher fretted notes sharp.

Even better, wouldn't be possible with slanted frets to spread the compensation across the whole fingerboard, leaving the nut and the saddle uncompensated?
Maybe keeping the compensation given on the frets below average levels, leaving fine-tuning compensation of each string to the classical saddle/nut compensation techniques.

I understand that it would be a problem with commonly available fret scale templates, but having the possibility of doing your own template or marking frets positions by hand wouldn't it be ideally better?

Probably I'm just proposing a centuries old method that is not used for some good reason, but it just came to my mind and I was wondering if it makes sense...

I just skimmed over parts, so forgive if I repeat. I saw an article once on how to compensate individual strings at the nut. I think that little rectangles of bone or plastic of different lengths were slipped under the strings at the nut. It would be beyond the ability of my tin ear to detect.

Jody, thanks for letting me know Ervin uses 1/16" nut compensation. Anyone have another suggestion or can anyone give reasons why to use this or another nut compensation length? Any reasons you would suggest not using nut compensation?

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Formerly known as Adaboy.......

Welcome, but my math that morning was off , that would be .0625. Jody