Intonation help

[sj9]

Hi, I have a Collings MT with a frustrating intonation problem. I have it setup so that the intonation is pretty much perfect on all strings when comparing the open and 12th fret. My problem is with the A course. Anything noted from the 1st through at least the 7th fret and maybe a little farther is sharp. G and E courses are perfect, D is close but also maybe a touch sharp but not very noticeable by ear. I can hear the A strings being sharp with every note. My friend has a super accurate tuner and we verified what I was hearing. I feel, but don't know for sure, that this started when I had a partial refret last winter. Is there anything I can check/adjust to try to make this better? The obvious answer is to take it to a good luthier but the ones people have recommended around here are > more than an hour away inconvenient to get to. I will probably end up going that way but wanted to check if there is anything simple that might be done at home before bothering.

Any advice is welcome.

[colorado_al]

Get some feelers gauges and Check the string height at the 1st fret on the A course (check all of the courses). If it is high, you will get sharp intonation, especially close to the nut. Cut the string slots accordingly. About .011 inches on the A and E strings, and .013 for G & D are normal

[sblock]

Hi, I have a Collings MT with a frustrating intonation problem. I have it setup so that the intonation is pretty much perfect on all strings when comparing the open and 12th fret. My problem is with the A course. Anything noted from the 1st through at least the 7th fret and maybe a little farther is sharp. G and E courses are perfect, D is close but also maybe a touch sharp but not very noticeable by ear. I can hear the A strings being sharp with every note. My friend has a super accurate tuner and we verified what I was hearing. I feel, but don't know for sure, that this started when I had a partial refret last winter. Is there anything I can check/adjust to try to make this better? The obvious answer is to take it to a good luthier but the ones people have recommended around here are > more than an hour away inconvenient to get to. I will probably end up going that way but wanted to check if there is anything simple that might be done at home before bothering.

Any advice is welcome.

Before doing anything else, check the action height at the nut for the A string. Is it higher than for the other strings? Does the string rest properly at the front of the nut slot? And if all that checks out, just try replacing the string and see if the problem goes away.

The frets and nut would seem to be are correctly positioned, based on results from the other strings. The bridge is correctly positioned, based on the octave and harmonic comparisons. So either it's the nut slot being too high, or cut wrong, or a bad string (e.g., with a nonuniform cross-section).

[Folkmusician.com]

Agreed. Suspect the nut first. This is most likely

[sunburst]

I agree that checking string height at the nut is the first thing to do, and adjusting that could fix the problem...
If it does not, however, there are things that can be done to improve the situation. How often do you play a the 12th fret compared to how often you play at the first 5 frets? At which frets is intonation most important? If the answers are; you play on 1 through 5 much more than fret #12 and so intonation is more important at 1 through 5, set the intonation so that it is slightly flat at fret #12 to improve things where you play most.
Also, the nut can be adjusted so that you have a "compensated nut".

Anyway, check the string height and the nut slots and expect improvement in intonation from any corrections there, but know that other remedies exist if you are still not happy with your intonation.

[Br1ck]

The other thing to be mindful of is that fretted stringed instruments buy their very nature are imperfect, and many is the luthier faced with an instrument an owner has checked at each and every fret with a tuner. Weather they can hear it or not, the tuner tells them it's imperfect. At best it's the art of arriving at the best compromise. Fan frets are done to mitigate this. I agree the nut is probably you problem, but perfect intonation is unachievable.

[Larry Simonson]

I have been struggling a bit with A string sharpness at the lower frets ever since the advent of modern tuners, Luckily? my hearing is is not so refined that I am bothered much but I bet others with a fine sense of pitch are. I agree with what has be written above but I have often thought that the "standard" bridge compensation may not be right for every mandolin. If the string length was made a bit longer by bridge compensation on the A string, a smaller proportion of that string would be consumed on fretting and the resulting note wouldn't be as sharp.

[sunburst]

[QUOTE=Larry Simonson;1686999...I have often thought that the "standard" bridge compensation may not be right for every mandolin...[/QUOTE]

That is correct. Bridge compensation can only be accurate for a certain action height and a certain set of strings. As the strings age, things change, so truly accurate bridge compensation is close to impossible. (It can be argued that accurate bridge compensation is impossible because of equal temperament and other factors.)

[Rob Meldrum]

As the others have said, it sounds like a classic case of your nut slots being too high. Email me at rob.meldrum@gmail.com and put Mandolin Setup in the subject line. I will email you my ebook on how to set up a mandolin. If you don't have nut files I will show you how to make a set for less than ten dollars.

You should find everything you need to know in the book.

Cheers!

Rob

[sj9]

Thanks for all the advice, I will probably give the nut slots a try.

[Ivan Kelsall]

From sj9 - " I have it setup so that the intonation is pretty much perfect on all strings when comparing the open and 12th fret."

Br1ck got it - Fret positions are a very good compromise - they are not perfect !. I set the bridge on all 3 of my mandolins so that the "A" strings,both open & fretted at the 12th fret, are tuned as accurately as i can get them. Having done that,i then tune all the other strings to my tuner. If i then check each course to it's neighbour at the 7th fret position,they're usually as close 'as needs be' (not 'perfect),except for the A to E strings. The E strings always seem a tad 'flat',so i tune them to the fretted A strings & they sound fine. I will say that my Ellis doesn't need this tiny adjustment. I put that fact down to Tom Ellis making his own 'perfectly' compensated bridges,
Ivan

[MarkELynch]

There are some very fine suggestions here!

Is it possible that when your mandolin was reassembled after being refretted that the saddle position was reversed? That might account for the change assuming the intonation was correct before.

As John Hamlet states, the intonation is only perfect for a certain bridge height and type of strings. Note that Gibson was dealing with this issue back in the 1910’s (according to their catalog) and makes specific mention of the compensation for the A strings. Since A strings are available either wound (Tomastik, etc) or plain (most everyone else) the early bridges had moveable separate saddles to account for the difference, especially important on the A string. What type of strings are you using?

Mark

[sj9]

I hope you guys are wrong and that is not just something that has to be tolerated! I don’t think the saddle is reversed. Strings are J74. It isn’t just the intonation, overall the A course just doesn’t sound good, can’t get as good of a tone as the rest of the instrument. Just seems harder to fret cleanly. This could of course be my playing technique. I’m away for the holiday without any instrument so will take a stab at the nut in a few days. I did check the height before I left at 1st fret and the A was ever so slightly higher than the E, just above 0.011.

[Tom Wright]

In my experience .011” is too high above the first fret. I consider .007” kind of high but has good tone if your fret layout yields good pitch in the low frets.

BTW, reversing the bridge saddle has no effect on effective string length, as you will see if you draw the shape and rotate it 180 degrees. The bridge slots can be different, of course, for the thicker strings, but the staggered shape is unchanged by rotation.

[Walt]

The other thing to be mindful of is that fretted stringed instruments buy their very nature are imperfect, and many is the luthier faced with an instrument an owner has checked at each and every fret with a tuner.

When I was in college I got roped into playing electric bass for the school's jazz ensemble. Our instructor was a killer jazz guitar player whose chops were insane. First day, he met with me and the guitar player and asked if we knew how to tune our instruments. Thinking that he would be privy to some secret knowledge for getting an instrument to play perfectly in tune, I said "no." He responded with the very rudimentary "put your finger on the fifth fret, and the next strings should match that pitch." I explained that I knew the basics, but I had never been able to get an instrument to play perfectly in tune.
His response was, "It's a guitar. Get over it."

That's not to dissuade OP from fixing his problem--it sounds like it's something to be improved upon. But I agree with others here that intonating requires compromise.

[MarkELynch]

BTW, reversing the bridge saddle has no effect on effective string length, as you will see if you draw the shape and rotate it 180 degrees. The bridge slots can be different, of course, for the thicker strings, but the staggered shape is unchanged by rotation.

Tom, there may be saddles cut the way you describe but ones that follow the old Gibson pattern and not symmetrical end-to-end.
Here are two examples. One is the patent drawing for the first adjustable Gibson bridge with the aluminum saddle, the second is the Randy Wood “Loar replica” bridge. Notice the position of the offsets in the saddle.

[Tom Wright]

Yes, I see your point, the rotational symmetry is altered to make a larger offset for the G/D pair than for A/E. I've seen some that have essentially no difference from one end to the other. The Randy Wood bridge exaggerates a bit more than the Gibson. It would still make only a modest difference if deployed rotated 180 degrees, as the compensation is still approximately correct for the pairs of wound and plain strings, i.e. back for thicker string, forward for the thinner one.

Gibson before and after rotation--


Randy Wood before and after---


I've been thinking, perhaps incorrectly, that people expected a mirror-reversed difference after rotation, like this---



If this were true it would substantially out of tune.

[Jeff Mando]

Several thoughts.....

Years ago I had a favorite Les Paul refretted and it never played right again. I had no logical explanation for it, as the new frets could only go in one place, right? Anyway, I ended up selling it to "solve" the problem -- for me, at least.....

A friend liked to gig out with old Harmony and Silvertone guitars, but complained of them being "out of tune" meaning intonation-wise, we even tried putting tunematic bridges on them with no luck. I finally came to the conclusion that he was "cursed" with having too good of an ear for music....

On the other hand, a Collings is not a Harmony and should be able to be in tune. There is a solution somewhere....

An old trick from my days working at a guitar shop -- put some flatwounds on it -- it'll sound more in tune (for some reason) -- think Beatles, etc....

Also, not the case here, but flatwounds seemed to "make playable" guitars in need of a fret job, FWIW.....

[Carl23]

Ok, I might be totally off the deep end, but I set my bridge at a slight angle. So that the g end is farther from the nut than the e side.
I tune the position by bringing the g and e up to pitch then tune the 12th, 7th and 5th harmonics. I try to be particularly aware of the position that makes the harmonic, too far from the fret and I adjust the bridge accordingly.
Does this make sense to anyone else?

Carl

[pops1]

I will carve the saddle for each set of strings if any don't intonate. They are usually thicker than need be and you can get it so as many of the pairs are good, and take wood off front or back of the saddle for the ones that don't. Every mandolin will not be the same and the offsets on the saddle are not meant to be "correct" but a starting point.

I have an A2 that was in the transitional time in the loar era that would not play in tune. After fighting it for quite a while I was going to make a new fretboard because it sounded so good, just wouldn't play in tune. After measuring frets I discovered the nut was about 1mm too close to the first fret. A shim moving the nut back made it play in tune perfectly. I have seen this in other '22 Gibson mandolins. For the OP if they took your nut off for new frets, which I would do to level frets properly, it may not be correctly back in place. It affected my A strings most.