Problem after Bone Saddle

[DRK HRSE]

I ordered and received a Saddle fro Mr. Colosi... took it to a shop to be installed... Action is just right... BUT the 2nd string intonation is off.... Using my Chromatic Tuner... B string Open stays Dead on Perfect note for > 6 seconds, but fretted at 1st - 8th frets it shows about 1/4 note high!!!

Ideas guys

Please don't think I'm knocking Colosi... the Saddle and associated pieces I ordered were beautiful... the technician even raved about them.... I think the problem lies maybe in the Compensation cut being lower (Action Height) than Bob intended???

[aylorTay anFay]

How was the intonation with the original saddle?

[DRK HRSE]

DEAD ON!!!

Sorry it is a 814-CE Limited Cocobolo... Sound was great, but action was a little high for my playing - Fingerstyle and many songs have full or hinge bar chords up around the 9th fret and THEN Pull off's and Hammers!!!!

So after reading about the sound change after using a bone saddle (I also had a Bone Nut installed using the offset string spacing - 6th string being fatter than 1st etc - so the gap between each is the same) I decided to go that route and have the action worked on as well...

There was a Breedlove AC25-sr there with the perfect action... they pulled that one down and used it as a comparison for me...

[ljguitar]

Originally Posted by DRK HRSE

...So after reading about the sound change after using a bone saddle (I also had a Bone Nut installed using the offset string spacing - 6th string being fatter than 1st etc - so the gap between each is the same) I decided to go that route and have the action worked on as well...

Hi DH...
So the setup guy didn't check and correct the intonation on the 2nd string? Unless it is carved all the way to the back or front edge, it seems to me that they should (could and would) just touch up the compensation.

[Fngrstyl]

I could be wrong, but if the intonation is perfect Open B, and then off when fretted, is that the saddle?? If you correct it for the frets, then it would have to be off when played Open. Correct? There has to be a little compromise I would think.

[DRK HRSE]

NOPE... an open string can be set to any note you want (tension)...

[aschroeder]

Originally Posted by Fngrstyl

I could be wrong, but if the intonation is perfect Open B, and then off when fretted, is that the saddle?? If you correct it for the frets, then it would have to be off when played Open. Correct?

You are correct. It doesn't sound like the saddle to me. When intonation is off at the 1st fret, the problem is usually the nut. Make sure the string is set properly in the slot. Also check to see if that string is sitting up higher than the rest at the nut.

My bass guitar did the same thing on my low B string. I had to file the nut slot to correct the problem. If it is the saddle, I don't think it would occur so high on the neck. It would get worse as you got closer to the saddle.

[arluk3]

When I compare my Colosi bone saddle to the original Tusq saddle, I see that the flat area (the ledge) on top of the Colosi saddle is approximately .030" wider than that on the Tusq saddle in the region of the B string compensation, making the string effectively that much shorter. Is this enough to worry about ? The string seems to be a few cents flat at the fretted 12th compared to the harmonic. My Korg CA-30 tuner is pretty much useless here. Is there some kind of formula for how much material to remove when correcting intonation ? For example, by lengthening the string by .010", the pitch at the 12th increases by XX cents when fretted in comparison to the harmonic ? Thanks for any info.

[Roman]

If you're experiencing a sharper or flatter B than before - when fretting the 12th fret to the open string, than that .030" is and in my mind would make a difference. I just made a new bone saddle for my 814 and adjusted (compensated) the B and low E due to intonation. They're both perfect now!

[ljguitar]

Originally Posted by Fngrstyl

I could be wrong, but if the intonation is perfect Open B, and then off when fretted, is that the saddle?? If you correct it for the frets, then it would have to be off when played Open. Correct? There has to be a little compromise I would think.

Hi Fngrstyl...
An open string can be tuned to any pitch you want. The distance between the nut and 12th fret and the distance between the saddle and 12th fret must be identical, or the string will not fret in tune.

An easy way to check intonation of individual strings is to play the 12th fret harmonic and tune it, then fret the 12th fret and see if the note is identical to the harmonic. My Peterson tuner does a respectable job with 1,000th of a pitch accuracy for helping compensate saddles.

There are a couple other things which create problems with intonation:
- Old or defective strings
- Misplaced fret wire
- Miscut saddle slot, or a loose saddle (leans out of position).
- Very high action (you bend the string out of pitch just pressing it).

Compenstaion correction takes place at the saddle, not at the nut. If you corrected at the nut, you would throw the intonation off again by placing a finger or a capo on the guitar.

If the nut slot is cut too high, you can create intonation problems at the first few frets because you are stretching the string out of tune just by fretting it.

So Dark Horse probably should troubleshoot beginning with a new 2nd string to be sure it is not just a defective string. After that, compensation can still be done to the saddle if it is not pre-compensated fully in the ''wrong'' direction.

[DRK HRSE]

Originally Posted by arluk3

When I compare my Colosi bone saddle to the original Tusq saddle, I see that the flat area (the ledge) on top of the Colosi saddle is approximately .030" wider than that on the Tusq saddle in the region of the B string compensation, making the string effectively that much shorter. Is this enough to worry about ? The string seems to be a few cents flat at the fretted 12th compared to the harmonic. My Korg CA-30 tuner is pretty much useless here. Is there some kind of formula for how much material to remove when correcting intonation ? For example, by lengthening the string by .010", the pitch at the 12th increases by XX cents when fretted in comparison to the harmonic ? Thanks for any info.

I noticed the same thing..., the Ridge that would effectively be the string starting point was slightly different... NOW I do consider myself intelligent and adept and have even played with building a guitar... but messing with my baby??? NOPE... I'll most likely take it to the shop and work it out with them...

The string is brand spanking new as well... decided to try the Elixer PBs when I picked it up...

THX for the responses...

[ljguitar]

Originally Posted by arluk3

...Is there some kind of formula for how much material to remove when correcting intonation ? For example, by lengthening the string by .010", the pitch at the 12th increases by XX cents when fretted in comparison to the harmonic ? Thanks for any info.

Hi Arluk3...
Now that is an interesting consideration. Since the length of the string is mathematically measurable, & once the scale of the guitar is known...theoretically if your measuring tools were precise enough, one could base the length properly by measuring the total length of the string when the fret is pressed.

My doubts come with the ability to measure and correct the small amounts of distance correction we are discussing with common rulers. We are probably dealing with 1/128th inches, & my rulers don't go past 1/32''.

Charley Hoffman (Hoffman guitars of Minneapolis) expresses nut widths in 1/32'' rather than 1/16''s that we use around here. He expressed some 1/64'' measurements on a guitar question I asked him at Healdsburg. It's hard for me to think that small!

Mathematical measures versus audio measures...
Men were put onto the moon & returned safely to earth by scientists who still employed the use of primitive slide rules. However, the invention of the electronic calculator (computer) made this job - and others like it - swifter and simpler. The musical ''electronic'' calculator is a very precise tuner (like the Peterson strobe tuners).

Those moon launching scientists did crunch numbers on a room sized calculator. We'd probably not have launched men as quickly if we were still using slide rules. Too crude and too slow.

The rough mathematical map should have been completed when the guitar was constructed, so intonating is a fine tuning of the original intonation process.

Formulas versus using a tuner...
I think a better case could be made for intonating strings simply by using one's ear than with one's eyes (rulers). Depending on how sensitive your pitch discrimination is, you might be able to set the intonation only by ear.

Original question...
If one were to construct a formula, it would have to include scale length, angle of the neck in relation to the face of the guitar, height of the top of the saddle from the face of the guitar at every string, and string height at the 12th fret as well as length of the string where it touches the 12th fret wire when depressed, and the deflection of the neck.

It's not a simple matter of string length. If your action is higher it affects pitch more than if low...you bend the string sharper. It is the pressed length that counts, not just the overall length. If strings are heavier, they change pitch differently when pressed than if lighter.

It seems easier to me to use a good tuner and your ear...but I'd love to see the formula! There may be one in existence.

[ljguitar]

Originally Posted by DRK HRSE

...I'll most likely take it to the shop and work it out with them...

Hi Drk Hrse...
Please tell us more about the guitar you ''played with building...'' After watching a great deal of my Bashkin being built, I don't have the patience, or concern for detail it would take to build one. I'm in awe of those who build them and have respect for those who attempt the process.

I think it's wise to take it back and have the setup completed to your satisfaction. On the surface - based on your explanation - it just sounds like the length of the string at the saddle needs tweaking...

[110-GB]

And that makes it final! I'm going to have a luthier install my just recieved Colosi FWI saddle. :-)

[Guyute]

Did you by any chance happen to email Bob and ask his thoughts?

When in doubt, go to the source.