Earvana nut > 1st fret?

[big_teee]

Here's a site that gives string gap measurements for guitar setup.
This gives a good starting point.
Key measurements in electric guitar setup.
YMMV,
T
**No popcorn, but I have Peanuts!

[bbsailor]

Guitar tuning has always been an approximation for the following reasons. I have to revise my math procedure below. Sorry!

1. The frets are placed at the 12 root of 2 spacing interval. https://en.wikipedia.org/wiki/Twelfth_root_of_two. Take the length of the open string and divide it by 1.059463 to get the distance from the bridge to the first fret. Subtract this number from the string length to get the distance form the nut to the first fret. 25.5/ 1.059463 equals 24.0688. Now, divide the remaining string length from the first fret to the bridge and divide this slightly shorter distance by 1.059463 to get the spacing from the second fret to the bridge (a little shorter distance between frets as you go up the neck). Do this twelve times and when you get to the 12th fret you should be at exactly one half the string length and be at twice the frequency of the open string, thus the origin of the 12th root of two. The fret spacing follows this mathematical spacing but on guitars there is more to consider to stay in tune.

2. Strings have two lengths, (1) the physical length and the (2) speaking length. The size and flexibility (stiffness) of the string, when it rests on the nut, bridge or fret starts to vibrate slightly forward of the contact point so its speaking length is slightly shorter than its physical length. This is why you see bridges offsets with the B or G string being longer as it is typically thicker and stiffer than the high E string and needs a little longer physical length so its speaking length is more in tune.

3. The height of the string above the frets (action) and neck relief (neck bend adjusted by the truss rod tension) cause the strings to slightly go sharp when pressed down to the fret. This stretch is variable as each guitar is set up differently, uses different string gauges and reflects user set up preferences and playing styles (soft picking versus hard strumming).

In order to minimize these effects the bridge of most guitars is slanted to make the bass strings longer because their speaking length needs to be lengthened slightly to be in tune. Guitar tuning has always been a compromise between ease of playing, string gauge used, playing style and comfort to the ear.

In my experience, using 25.5 inch string length scales (Fender, typically) I like to use .011" high E string sets. On my shorter scale 24.75 scale length guitars (Gibson typically) I like to use .012 string sets. Shorter scale lengths require a little thicker string diameter to maintain a similar feel.

Most guitars come from the factory requiring some fine tuning of the nut height. This adjustment should only be done using your favored string gauge. Here is how I do it.

1. Select and install the string gauge you like.
2. Tune to pitch. Play a barred F chord and note the feeling.
3. Straighten the neck using the truss rod adjustment (no bow).
4. Press the string down at the 3rd fret and the string will rest on the 2nd fret. Look at the space between the bottom of the string and the 1st fret.
5. Lift the string out of the nut slot still in tune (do not change string tension).
6. File nut a very little wider than the string diameter to prevent binding. File a little and check a lot to not over file the nut slot too deep.
7. Stop filing when the string is about the thickness of a piece of paper above the 1st fret.
8. Add relief to the neck and the distance from the string to the first fret will increase slightly.
9. Do this to all the strings keeping the guitar in tune as you fine tune your guitar.
10. Enjoy your new setup. Play a barred F chord to see how much easier it is to play then before.

I hope this helps.

Joseph J. Rogowski

[Sea Chief]

I'm probably going to take a beating for this, but...

I'm in total disagreement with compensated nut systems. When you consider that the entire fingerboard is designed with tuned intervals, my logic reasons that changing only the first interval will invariably render it incorrect. How is it even possible for that first interval to play in tune if it doesn't follow the same gradient as all those after it. Compensating at the saddle is even a compromise, but the best one we have. Compensating at the saddle allows for averaging the amount of "out of tune-ness" across the strings fretted length. Ideally, compensation would be done at each individual fret. This is, of course, impractical for a number of construction and operational reasons. My point though is that compensating at the nut, by my limited reasoning, seems like the worst possible place. I'm sure there are some good sounding explanations by those that make and market nut compensation devices for why it works, but I wouldn't be surprised if only certain reasons are addressed while other considerations are ignored. It's my opinion that these systems, while they look cool and high tech, are the result of a limited view of the whole system, can't work and are only being sold because people buy them. In the whole picture it doesn't make sense to me. And I doubt you will ever be able to tune the guitar satisfactorily before the compensated nut system is removed and replaced with a normal, straight nut in it's proper location relative to the first fret.

I'm going to pop some corn.

Your absolutley right.. but I think your thinking too much albeit completely rationally. If you actually play one, its actually a remarkably good system- and only seems to affect the first position, which often is the cause of slight intonation problems. Mine before was so sweetly in tune anywhere.. now after the refret its a struggle. Sheesh hey-ho.

[Sea Chief]

Here's a site that gives string gap measurements for guitar setup.
This gives a good starting point.
Key measurements in electric guitar setup.
YMMV,
T
**No popcorn, but I have Peanuts!

Useful and clear page for ref.. bookmarked/ but not for the issue in Q here tho, it doesnt have anything on nut > 1st fret distance, or anything on a compensated nuts.

[big_teee]

If it was great before, why the refret?
The old Cliche comes to mind!
"If it Aint Broke, Why Fix it" ?
Just Saying!
I would take it back to the Refretter, whatever he charged!

[Sea Chief]

The intonation process is as follows: First plug into a tuner. Then play the open string harmonic at the 12th fret(octave) and compare the reading on the tuner with the fretted note of that 12th fret. The pitch should be the same +/- a cent. If the fretted note is sharp, lengthen the scale by moving the saddle back until the harmonic and fretted notes match. If it is flat, the saddle should be moved forward. Usually, it won't take much movement to accomplish this. Go in small increments and try again until it matches. When finished, retune all strings with the tuner and repeat the process to ensure all strings are still matched according to the above process. I would do this with the Earvana in the central position as this will allow you forward or backward adjustment of that nut.

To answer your next Q, The 25.5" scale a standard the same as an 8 ohm speaker is a standard. It is many other impedances at different frequencies. I suppose also it's to differentiate between 24.75" for Gibsons. The exact scale is determined by the intonation process. Usually, it won't take much movement of the saddle to get it right, so I doubt if measuring with some sort of ruler is the way to go anyway.

Understood.. but if I set the 12th strings and adjust at the saddles the get the harmonic matched.. then I have to shift the nut a bit, the whole thing will be out.

Hence my reasoning that beofre anything related to intonating a gtr, surely the 1st and fundamental thing (apart from having a fretted board and 6 strings over an adjustable bridge) is to know that the nut is set in correct postion relative to the 1st fret.. or a heck of alot of time would be wasted of needs all to be redone. Fine for a std nut: its simply 36.3mm (apparantly- tho my other two 25.5" gtrs are both 36.6mm?!). But each of my nut positions are not standard 36.3mm.

[Sea Chief]

Nah. What he needs is a zero fret.


Me too. This should be fun.

-rb

PS- Possibly useful suggestion (just guessing)
If your fretted notes are flat, that suggests to me that your frets are now higher than they were before, so the fretted strings are now being stretched less than before. Moving the nut closer to the first fret should stretch the fretted strings more, raising the pitch of the fretted notes. (Raising the nut would also stretch the strings more, but I don't think you'd want to do that unless the strings are buzzing on the 1st fret). The limit for adjustment would be that you don't want to get any closer to the first fret than where one would place a zero fret (according to that square-root-of-twelve formula, whatever it is). If you get any closer than that position, all fretted notes will be sharp. I think.

Yes I understand and agree- actually I did shift the nut fwd on the top side intuitively to try and sharpen those flat notes. It did (byut I got in a mess undoing all 3 tiny screws and dont know where im at now- thought there must be a reference A to B measurement I need to proceed or Im farting in the wind).

So does that mean there isn't neccessarily a designated set firm figure for a nut > 1st fret, as frets will invariably be of different heights-?

[Sea Chief]

I always have problems tuning the 3rd string, unwound G. My 'nut compensation' routine is to ensure that the string is in tune at the second fret A so that the "rock" chords all sound in tune. The open G is a tiny bit flat, but not so much as to be noticeable. I think I'm really splitting the difference there. The guitar has a fixed bridge, so once the bridge is intonated it's a matter of majority rule for the individual strings!

But that is exactly what these Earvana nuts solve. The G string is set into the 1st position by a few mm's compared to the E's for eg. Your rockON chords -and- your open G will all be in tune. Dont think too much as to how/ 'b b but why'.. it just does I assure you.

Presuming you have the damn thing set correct to 1st fret that is!

[Sea Chief]

I would think it is the above^^ As the intonation is flat at the first few frets I'd try moving the nut back (to make the string longer). If that doesn't fix it the action at the first few frets will have to be adjusted by raising or lowering the nut. SC are the new frets higher or lower than the originals?

Yes indeed the new frets are higher than orig's (I did mention this in #7, but maybe not clear enough) and thought straight off it was the reason why the D chord now is flat on the top strings. But the nut can only be compmesated fwd / back.. not up or down. And I must be sure it needs a shim added before I venture down this route.

But I still need at least one definitive figure, like the 36.3mm for a std gtr, before I do anything.. or Im farting in my soup.

[big_teee]

My strat measures 1.429" from behind the nut to the middle of the 1st fret.
It has no intonation issues checked with a electronic tuner.
All fret positions are in reasonable tune, with a standard nut.
The bridge saddles measure 25-5/8" on the big E, and 25-7/16" on the little E.
Measured from the back of the nut. Strings are Slinky 10s.
T

[Dave H]

I did shift the nut fwd on the top side intuitively to try and sharpen those flat notes. It did

If 'fwd' is towards the bridge it should make the first fretted note play flat not sharp because the distance from nut to first fret is reduced. If the action is high at the nut it could possibly go the other way I suppose but I'm not sure. Measure the first fret action by holding down the string between the second and third frets. There should only be a tiny gap between the bottom of the string and top of the first fret.

[tedmich]

I am aware of three different approaches to improving intonation: Earvana, Feiten, and multiple scale (fan-frets).

I am in no position to compare them, but I'd be interested on folks' experience with them or any discussion on the pros and cons of these various approaches.

I think these issues are very real for musicians with good pitch and exacting engineer types (and combinations thereof!) but are largely irrelevant to most guitarists. To your typical player its a solution in search of a problem but players who are gifted with excellent pitch are often happy to pay for anything which purports to correct the inherent inaccuracy of traditional guitar designs.

The phrase "close enough for Rock'n Roll" comes to mind...

[big_teee]

The phrase "close enough for Rock'n Roll" comes to mind...

More Gain & more Volume also comes to mind.
That's why on the 8th day God Made the JCM800 100 Watt Marshall.

[eschertron]

That's why on the 8th day God Made the JCM800 100 Watt Marshall.

That's the problem with this younger generation. I was thinking "Bridgette Bardot".

[rjb]

Understood.. but if I set the 12th strings and adjust at the saddles the get the harmonic matched.. then I have to shift the nut a bit, the whole thing will be out.

But if you first adjust your bridge by capoing at the 3rd fret and checking fretted notes vs harmonics at the 15th fret, you eliminate the nut from the equation and your bridge should be spot-on.
More or less. Theoretically. I think.
OK, I'm obviously guessing.
I'm outta here.