Questions on intonation

[pvan]

I was wondering if some experienced guitar techs can comment on intonation in general and the bridge shown in the picture below.

I heard a while back that theoretically, a properly intonated guitar would have the saddles arranged in two "step" patterns. This is where the high E would be closer to the headstock than the B and G, with the B closer to the head stock than the G. This pattern then repeats on the D, A, and low E. This made sense to me based on the concept that if the nut was cut properly, and the bridge was even or parallel to the angle of the nut, then the distance from nut to bridge should be equal at any point across the bridge. The "step" pattern would result from the different gauges of the strings requiring more or less distance. A possible exception to this would be where a bridge would be angled to compensate however I think that would just minimize the size of the "steps".

Please refer to the 2nd, 3rd and 4th pictures for bridges with saddles in the "step" pattern and the PRS stop tail compensated bridge.

Now in the real world, I'm not sure if this applies at all times. More specifically, the reason for my question is I had my guitar setup recently and my bridge came back as seen in the first picture. I checked intonation using a Peterson strobe tuner and on the Line 6 moble IPad modeling software and at least 4 strings are out checking open string against fretted 12th and open against 12th fret harmonic. I received the guitar back the first time and returned it because I wasn't satisfied the setup was correct, then received it close to the same way. When I looked at the saddle positions I was immediately suspect because I believe the "step" pattern theory is generally valid and when the saddles aren't close to following that, something is likely incorrect. Of course the shop says everything is spot-on but that's not what I'm seeing with my tuners. They use the small electronic tuners and I had mentioned the "step" pattern when I brought it back. It appears they tried to get it with the G, B, and high E, although the high E is doesn't register as intonated correctly.

Thanks for any advice.











Is my belief in the "step" pattern wrong? Is it possible that a bridge with saddles arranged like seen in the picture could be intonated properly given the nut was cut properly? Am I checking my intonation incorrectly?

[Elwood]

I find the step pattern applies 99% of the time, but I will occasionally get a bad string that doesn't intonate (or sound right).
Case in point...I've been playing my Skyhawk daily for the last 8 months,with the same strings.
I wanted to see just how long these TI powerbrights last. The high e finally gave up it's integrity, it won't intonate
within the saddle adjustments. I tried to adjust it to put off changing strings , and it ends up looking like your first picture.

Try another set of strings ( or just a high e ) before you come to any firm conclusion , some string manufacturers aren't as consistent as we would hope.

Are you using a 'light bottom' set? that would lessen the step distances for the E,A, and D saddles...that's all I can come up with for now.

elwood

[pvan]

Thanks for the input Elwood. Actually it's a heavy bottom set. The strings are brand new so age isn't a factor.

[Elwood]

Thanks for the input Elwood. Actually it's a heavy bottom set. The strings are brand new so age isn't a factor.

I have had new strings that weren't right . I was just using my example that strings that aren't right will vibrate in a way that alters the fundamental. You might try changing the high e out just to see if you got a bad one.

It looks like the low strings are bottomed out (springs are tight) , maybe the tech didn't want to cut the springs
to bring the E and A back further (though it looks like the 'g' string spring has been shortened) . Are the low strings intonating sharp?

[pvan]

I don't have the guitar near me now, but the ones that were out were sharp. I think the low E was sharp, the A was good and I'm not sure about the D. I think the high E was sharp also but I would need to check them again to confirm. You are correct about the springs, I think they did cut the G. I will try a new set of strings and see whether that changes things.

Thanks for the input.

[yowhatsshakin]

Still, the question remains why after handing it twice to a tech to be set-up and intonated (I assume) it comes back poorly set up. You did your litmus test and I reckon also the second time it came back not well intonated. You wonder what method that tech was using and from your story, the kind of tuner you are using (the Peterson) is way the heck better than what they use. The only thing I can think of is the pressure you use when fretting the string which can pull the string sharp when excessive. But that would not affect checking it with the harmonics.

Since you have a Peterson strobe tuner, next time you might as well intonate the guitar yourself.

- Jos

[Elwood]

You might have to remove the low E spring to make it work ( since it's a heavy gauge).
If the D is a hair flat...then you might see the 'step pattern' reappearing after your adjustments.

Hope things get closer or perfect ; )
elwood

[pvan]

Still, the question remains why after handing it twice to a tech to be set-up and intonated (I assume) it comes back poorly set up. You did your litmus test and I reckon also the second time it came back not well intonated. You wonder what method that tech was using and from your story, the kind of tuner you are using (the Peterson) is way the heck better than what they use. The only thing I can think of is the pressure you use when fretting the string which can pull the string sharp when excessive. But that would not affect checking it with the harmonics.

Since you have a Peterson strobe tuner, next time you might as well intonate the guitar yourself.

- Jos

Thanks Jos, that is my plan. I had taken it to the shop for a Plek and setup. I was having some trouble getting it intonated accurately from running out of adjustment and was hoping the shop would come up with a resolution but it seems they have the same problem (except apparently it's not considered a problem!). The reason why it came back that way? I think it may be the quality of tuners they're using, or it's "close enough for rock and roll", or to get it right is more work than is warranted for a $400 guitar when there are customers buying $4000 guitars. To be fair, I could take it back again with my tuners and compare notes, but it's a 2 hour round trip and I'm pretty much tired of that. I may do that just to see who's doing what wrong.

[pvan]

You might have to remove the low E spring to make it work ( since it's a heavy gauge).
If the D is a hair flat...then you might see the 'step pattern' reappearing after your adjustments.

Hope things get closer or perfect ; )
elwood

Thanks, I may try that.

[NickHorne]

Don't be afraid to leave springs out if you have to; there's plenty of string tension holding the saddles in place anyhow!
But you just might have to cut a little off the bolts if they end up hitting the strings as they come up through the saddle. This will need a vice and a sharp hacksaw, but the amount to cut can be easily worked out and is not critical as long as there is bolt all through the threaded part of the saddle, with a bit to spare for future adjustments. A suitable nut, threaded over the bolt before cutting, will ensure that the threads are clean afterwards; just wind the nut off to tidy up the cut end. But if you cut cleanly, you may well be fine without this precaution. Just go carefully when first refitting the saddle, so as to avoid crossing threads up at all.

The octave harmonics, i.e. the pitch of the string when touched at its halfway point, will always be very nearly in tune, regardless of where the saddle is. Any other result indicates either a weird tuner or a bad string. A small amount of sharpness can occur with heavy strings, due to the stiffness at the ends effectively shortening the vibrating length.

From the look of your photo, I reckon you'll get there OK. Why not just remove the springs from the sharp offenders, and then see if you even need to bother cutting them; you may well just not need to refit them at all. I have liked heavy E6'S for years, and leave the springs off strats routinely...

[yowhatsshakin]

The octave harmonics, i.e. the pitch of the string when touched at its halfway point, will always be very nearly in tune, regardless of where the saddle is. Any other result indicates either a weird tuner or a bad string. A small amount of sharpness can occur with heavy strings, due to the stiffness at the ends effectively shortening the vibrating length.

Good point Nick! For intonation one should always fret at the 12th, where finger pressure now becomes important for reasons described earlier. You can go all fancy and fret at different positions to figure out the 'tempered' intonation, i.e. the saddle position that make most (or your favorite) positions play exactly in tune. Now one knows why there is such a thing like the Buzz Feiten tuning system, or why there are so many tempered tunings available; many of which you'll find on a Peterson tuner.

- Jos

[Elwood]

A suitable nut, threaded over the bolt before cutting, will ensure that the threads are clean afterwards; just wind the nut off to tidy up the cut end.

All my years in carpentry and I don't think I've done that ( at least not on purpose).
thanks for the tip Nick

[KenC]

Pvan,

Aside from the question about the saddles, how does your guitar's action feel since the setup? Too much neck relief could require the saddles to be tightened all the way back like yours are. Do you know whether the tech shimmed the neck at all? Do all of the notes on every string ring clear, or are there any dead spots or buzzing?

Ken

[pvan]

Don't be afraid to leave springs out if you have to; there's plenty of string tension holding the saddles in place anyhow!
But you just might have to cut a little off the bolts if they end up hitting the strings as they come up through the saddle. This will need a vice and a sharp hacksaw, but the amount to cut can be easily worked out and is not critical as long as there is bolt all through the threaded part of the saddle, with a bit to spare for future adjustments. A suitable nut, threaded over the bolt before cutting, will ensure that the threads are clean afterwards; just wind the nut off to tidy up the cut end. But if you cut cleanly, you may well be fine without this precaution. Just go carefully when first refitting the saddle, so as to avoid crossing threads up at all.

The octave harmonics, i.e. the pitch of the string when touched at its halfway point, will always be very nearly in tune, regardless of where the saddle is. Any other result indicates either a weird tuner or a bad string. A small amount of sharpness can occur with heavy strings, due to the stiffness at the ends effectively shortening the vibrating length.

From the look of your photo, I reckon you'll get there OK. Why not just remove the springs from the sharp offenders, and then see if you even need to bother cutting them; you may well just not need to refit them at all. I have liked heavy E6'S for years, and leave the springs off strats routinely...

Thanks Nick, good info. I never considered dropping the springs altogether but I reckon you're correct regarding plenty of spring pressure to keep things in place.

[pvan]

The octave harmonics, i.e. the pitch of the string when touched at its halfway point, will always be very nearly in tune, regardless of where the saddle is. Any other result indicates either a weird tuner or a bad string. A small amount of sharpness can occur with heavy strings, due to the stiffness at the ends effectively shortening the vibrating length.

Good point Nick! For intonation one should always fret at the 12th, where finger pressure now becomes important for reasons described earlier. You can go all fancy and fret at different positions to figure out the 'tempered' intonation, i.e. the saddle position that make most (or your favorite) positions play exactly in tune. Now one knows why there is such a thing like the Buzz Feiten tuning system, or why there are so many tempered tunings available; many of which you'll find on a Peterson tuner.

- Jos

Thanks for that info Jos. I've never been a fan of the harmonic method mainly because I always seemed to have inconsistent results compared to what I was seeing by fretting at the 12th fret but I always see it mentioned in intonation discussions. I figured I'd try it just to have my bases covered.

[pvan]

Pvan,

Aside from the question about the saddles, how does your guitar's action feel since the setup? Too much neck relief could require the saddles to be tightened all the way back like yours are. Do you know whether the tech shimmed the neck at all? Do all of the notes on every string ring clear, or are there any dead spots or buzzing?

Ken

It's okay, could be a bit lower and I actually discussed the genesis of this issue in this thread: http://guitarsbyleo.com/FORUM/viewtopic ... 13&t=11320

Basically, the bridge couldn't be set to the recommended factory height of 2/16 because the saddles were bottomed out and the action couldn't go lower. I really like having the 2/16" height due to the ability to pull up on the bar. I have an S-500 that is setup that way with great action, ample saddle height adjustment and correct intonation. Having the S-500 setup like this and not being able to achieve it on the Legacy made me think something was wrong, hence the trip to the shop. They were able to get it a little better but it still doesn't seem correct. The neck doesn't seem to have too much relief, it's fairly close to straight. I don't think the neck was shimmed and that is actually what I'm considering next. I may do it myself or take it to another Luthier where I have credit for some work to be done and isn't over an hour away. The strings ring clear and there isn't any buzzing. They did a good Plek job and an outstanding job on the S-500. The guitar is playable the way it is now, but it's not optimal for me. I may be deceiving myself but I swear I can hear the intonation out if I play a D chord shape in the open position and then at the 14th fret (top 3 strings only). The open position sounds fine and at the 14th fret it's close, but there is a perceptible dissonance (not sure if that's the right description). The goals are to maintain 2/16 bridge height, lower the action slightly, and tighten up the intonation. I could lower the bridge slightly but I don't believe that would get the intonation correct. I think I'll try removing some saddle springs and see if that works. If the intonation is good, then perhaps I'll try lowering the bridge.

Thanks for the input, I appreciate the knowledge sharing.

Phil

[darwinohm]

Phil, I think you are right on and I would keep the DF height where you want it, shim the neck so you can lower the action and keep the saddles higher on the bridge. That will most likely solve the issues you are having. Doing it yourself is a good idea and if you need help, there is a lot of info and help on this forum.-- Darwin

[pvan]

Phil, I think you are right on and I would keep the DF height where you want it, shim the neck so you can lower the action and keep the saddles higher on the bridge. That will most likely solve the issues you are having. Doing it yourself is a good idea and if you need help, there is a lot of info and help on this forum.-- Darwin

Thanks Darwin. Have you ever shimmed a neck? I'm not quite sure what to use. There is a bit of conflicting information out there. I recently read this article where they say you should use a full neck pocket shim.

http://www.premierguitar.com/articles/1 ... lt-on-neck

I've also seen small stickers used for shims on the neck heel of one of my guitars. Any recommendations? That article said if you don't use a full neck pocket shim you can warp the neck.

For starters, don’t use paper or plastic, and above all, only use a “full-pocket” shim. Here’s why a full-pocket shim is essential: When someone uses, say, a matchbook cover or guitar pick, it leaves a gap between the body and neck. Over time, the screws holding the neck force it to fill that void. As a result, the neck warps and the end of the fretboard looks like a ski jump. Next thing you know, the fretboard has to be sanded to remove the warp and then refretted. If you’re lucky, the neck will have a thick enough fretboard to allow resurfacing. If not, the neck is a total loss. Either way, it’s going to cost you hundreds of dollars.

To avoid these problems, use a full-pocket shim that fits inside the entire neck pocket and is shaped like a thin wedge, with the slightly taller end facing the bridge This raises the end of the fretboard just a bit, which is what you want when correcting a neck angle that’s too low.

I suppose that is certainly possible but I don't know how probable. I would certainly go that route if it weren't for the issue of making that type of shim accurately.

[pvan]

Phil, I think you are right on and I would keep the DF height where you want it, shim the neck so you can lower the action and keep the saddles higher on the bridge. That will most likely solve the issues you are having. Doing it yourself is a good idea and if you need help, there is a lot of info and help on this forum.-- Darwin

Darwin, I just went to my other post and saw you were the one that recommended the .015 brass shim. Any idea where I would get one?

Thanks,

Phil

[darwinohm]

Phil, I just buy small brass plates at our local hardware store. I have .015 and .030 stock but I would start with the .015 and cut it to fit between the 2 screws closest to the neck picup and the edge of the neck pocket. I have done quite a few guitars as I like low action. -- Darwin

[pvan]

Phil, I just buy small brass plates at our local hardware store. I have .015 and .030 stock but I would start with the .015 and cut it to fit between the 2 screws closest to the neck picup and the edge of the neck pocket. I have done quite a few guitars as I like low action. -- Darwin

Excellent, I will check that out. Thanks for the tip!

Phil

[darwinohm]

Don't overtighten the neck screws after shimming. Just good and snug will do it. Over tightening can cause issues later on. -- Darwin

[pvan]

Don't overtighten the neck screws after shimming. Just good and snug will do it. Over tightening can cause issues later on. -- Darwin

Good reminder, I have been known to be a little too enthusiastic with nuts and bolts in the past.

[KenC]

Phil,

This is a shot in the dark, but it might be worth checking. If you have a 36" metal rule, compare the length of each string on this guitar to its counterpart on your S-500. That may give some clues about what's going on with the geometry.

Ken

[helle-man]

Phil,
If you have a 36" metal rule, compare the length of each string on this guitar to its counterpart on your S-500. That may give some clues about what's going on with the geometry.

Ken

I agree, Ken. That's where I would start. And make sure you have a fresh set of strings on the guitar. Some strings are defective and won't intonate correctly. All it takes is 1 string out of tune to make the guitar sound completely out.

My 2¢
Will

[pvan]

Phil,
If you have a 36" metal rule, compare the length of each string on this guitar to its counterpart on your S-500. That may give some clues about what's going on with the geometry.

Ken

I agree, Ken. That's where I would start. And make sure you have a fresh set of strings on the guitar. Some strings are defective and won't intonate correctly. All it takes is 1 string out of tune to make the guitar sound completely out.

My 2¢
Will

Thanks Ken and Will. I will check that out.