A-string intonation issue?

[jones]

All,

This may be a dumb newbie question but... I constantly struggle with keeping the A strings in tune up the neck. Specifically, If I tune the A and the E open, the A strings will be sharp at the 6th fret E. Just time for new strings or something more? Thanks!

[JeffD]

I think you mean the 7th fret E.

Could be lots of things. Is the A string considerably older, or newer, than the other strings? Is it a replacement of a different gauge than before?

Is it both A string that sharp, or do they go out of unison up there.

[pops1]

When you notice they are out of tune up the neck stop and take your time to carefully fret where you noticed it. If they sound in tune it may me you pushing them out of unison. I struggled with that many years ago and only on the A strings.

[Willie Poole]

I`m going to try and explain something that I have run into when setting up mandolins for other people...I have found that on mandolins that have been played quite a bit the frets have little grooves in them from the strings pressing down on the frets, then if someone moves the bridge slightly to the side of where it originally rested then the strings are pressed down into the grooves they slide into the grooves which are now not right under the string alignment and the string will give the effect of being stretched when it slides into that groove and will note off...

I hope I have explained this so you understand what I mean...Dressing the frets will take care of the problem, it doesn`t take much difference for mandolin strings to sound different than the other string in that pair...a strings seem to be the most trouble...

good luck....Willie

[Upis Land]

Another possibility it could be the mandolin/ setup. I once ordered a new mandolin which the A string was so far off as to make playing a tune impossible. I suspect it was an overcompensated bridge (in my case the A was flat) or nut problem or both. I ended up returning it to the builder. But a good setup could cure these things too.

[MikeEdgerton]

The bridge top may be reversed. I'd look at that first. Look at posts #10 and post #16 in this thread. Does your bridge top match that orientation? If so, continue to every other answer.

[jones]

Thanks everyone. I checked the bridge and it's OK. All the other hints are helpful too. I swapped out strings last night and that seemed to help. I'll have someone check the set up if this keeps up. Thanks again!

[John Flynn]

The A course always seems the most difficult on mandolins, not sure why. I have a mandolin from a well-known builder that had an A course problem that developed over time and eventually sounded so bad I felt the instrument was unplayable. I had to take to three very good luthiers before the problem got solved. In that case, the solution was to get the bridge slots to more precisely line up with the radius of the fretboard. Now the instrument sounds great! That is certainly something to check, but it may not be the solution in your case. It just amazed me how something so slight made such a big difference.

[terzinator]

The A-pair is notorious for being finicky (where the A strings are out of unison), and plenty of theories abound. If you search for "finicky pair" on the forum, you'll find multiple threads on the topic. (Some say that the A string is a wee bit too big to be a plain string, and a wee bit too small to be a wound string. Ahdunno.)

However, if you're talking intonation for BOTH A-strings at the same time, that's a different issue, kind of.

Too-high action might be a culprit, either at the nut or bridge. But also, like Mike said, bridge saddle might be reversed, messing up the scale length, or the bridge got nudged, and it's throwing off the intonation. Might just be that it's more noticeable on the A strings.

For either issue, though, fresh strings and a good setup will help.

[jimmy powells]

Most likely cause is the NUT. Some mandolins don't have the nuts slots correct. That means that the A string 15 guage may be trying to sit in a slot same as the 11 guage E string. End result is that the string is just a little too high making it sharp not just at 7th fret but all the way up to 7th fret as well. Have a VERY CLOSE look at the clearance under the A string compared to the E string at the first fret.

Other than that make certain the bridge top is the correct way round but if no luck, get a luthier to look at it and I'd bet he'd know within 5 minutes at most.

Jimmy P
UK

[sblock]

One fairly obvious thing is that if you're comparing the A-string FRETTED at the 7th fret to the E-string OPEN, your bridge might be in the wrong position. Have you checked this thoroughly?

[Tobin]

Yep, A strings are notorious for this. Just keeping them in tune/phase with each other can be a struggle, as I find they tend to sound "off" from each other more often than any other course. But intonation is very tricky with these as well.

Changing strings is always the first thing to do when you run across something like this. More often than not, it will cure the problem, or at least help a lot. Intonation on my A strings is usually the first sign that my strings are getting tired and in need of changing.

But beyond that, there's just an engineering dilemma with A strings. It's pretty much what terzinator described. That course is right at the border of being too small for a wound string and too large for a plain string. Banjo players have similar intonation issues with the 3rd string (usually tuned to G). Guitar players have a similar issue with the B string. So it's not just a mandolin issue, necessarily, it's just an engineering issue with strings. It is typically set to a compromise via compensation at the bridge. But compensation is not always perfect, especially if you're using a string gauge that's different than what the builder intended, as well as where the string is in its life span.

Remember: strings behave differently when they're new than when they start to age. That compensation at the bridge saddle is only going to work optimally at one particular snap-shot in time. The rest of the time, it's going to be more and more noticeably off. This applies to all strings, but it's just more noticeable on the A course, due to the gauge and tuning of that string. Mandolin players just have to learn to cope with it as best they can, and learn how to adjust.

With that said, it is important to note that setting intonation at the bridge can be done in several ways. Some folks set it using the outside courses (low G and high E). But if you do this, you may end up with D and A courses that sound "off", due to the compensation on the bridge not being perfect for that scenario. What you can try is setting your intonation based on the G and A courses, letting the D and E courses fall where they may. It may fix your A problem, but cause issues on another course. There's no master solution here, other than to experiment with which courses you use to set your intonation. Or find a bridge position that's not perfect for any course, but is the best compromise for all of them. Beyond that, the only thing to do is fine-tune your compensation by sanding the saddle until you have it perfect for all courses. And then never use any other type of strings than the one you're using now.

[Stevo75]

Other than that make certain the bridge top is the correct way round but if no luck, get a luthier to look at it and I'd bet he'd know within 5 minutes at most.

Jimmy P
UK

I don't understand the comments about the bridge being turned around. Can't they only go one way due to the size of the slots (i.e. it's easy to see the big slots go on the G string side and vise versa)?

[colorado_al]

I don't understand the comments about the bridge being turned around. Can't they only go one way due to the size of the slots (i.e. it's easy to see the big slots go on the G string side and vise versa)?

You'd think that, wouldn't you? I've seen plenty of mandolins with the saddle the wrong way round though. Many folks just don't pay that much attention when they're new to mandolins.

[Paul Hird]

A quick question on intonation, since we are on the topic. Is it not true that when adjusting the bridge for intonation the middle two courses, D & A are basically at the mercy of how well we adjusted the bridge for the G and E strings. If the G and E are intonated properly, one would assume the D and A strings will be intonated properly as well. However, if there is something "wonky" with either the D or A strings, or both and you have intonated the G and E strings properly, there is really nothing that will correct that with regard to intonation adjustments. When I adjust for intonation I only worry about the G and E since we cannot independently adjust each course. Just curious if I am on track or am missing something. Sorry this was so longwinded. Thanks for the replies.

[pops1]

I adjust the E and G, then I may carve if I have to for the D and A. If the bridge foot is crooked and the G needs to go back further that is a reason to flip the saddle around. I have seen some where the E and the G are to the front edge and back edge of the saddle.

[colorado_al]

A quick question on intonation, since we are on the topic. Is it not true that when adjusting the bridge for intonation the middle two courses, D & A are basically at the mercy of how well we adjusted the bridge for the G and E strings. If the G and E are intonated properly, one would assume the D and A strings will be intonated properly as well. However, if there is something "wonky" with either the D or A strings, or both and you have intonated the G and E strings properly, there is really nothing that will correct that with regard to intonation adjustments. When I adjust for intonation I only worry about the G and E since we cannot independently adjust each course. Just curious if I am on track or am missing something. Sorry this was so longwinded. Thanks for the replies.

This is the reason that mandolin saddles are compensated (not straight, but stepped). The string contact point on the saddle needs to be correct for each string. However, the factory "compensation" is just an approximation that needs to be fine tuned once you have set the bridge for good intonation on as many strings as you can. Changing the thickness of the saddle under each string, and also adjusting the location and depth of string slots. This can also be adjusted a bit at the nut, in unison with saddle compensation adjustments. Just go easy, you can always remove more wood from the saddle, it is really not possible to build the saddle back up.

[Tobin]

Is it not true that when adjusting the bridge for intonation the middle two courses, D & A are basically at the mercy of how well we adjusted the bridge for the G and E strings. If the G and E are intonated properly, one would assume the D and A strings will be intonated properly as well. However, if there is something "wonky" with either the D or A strings, or both and you have intonated the G and E strings properly, there is really nothing that will correct that with regard to intonation adjustments.

Yup, and I mentioned that in my previous reply. As I said, if you use the G and E to set intonation and find that either the D or A courses are off, then you can try setting intonation with the G and A, or the D and E, and see if it helps matters. It may also require a compromise where none of them are truly spot-on, but they are all off to a small degree that's acceptable to your ears. Unless, of course, you want to re-work the saddle.

[Mandoplumb]

Tobin's gpt it right. You can adjust the compensation and get it almost perfect, as close as is possible but if you change gauge or composition of strings it will no longer be perfect. When I adjust the position of the bridge, I use all strings, and 5th, 7th, and octive to try to compromise where all is close, and different strings seem not to change the compromise too much.