Third string out of tune below the fifth fret

[BeachMando]

Thanks in advance for any help/suggestions!

I just picked up one of the B-stock Gold Tone mandocellos that was on the classifieds. Overall nice instrument - a subject for a different thread.

I have one major issue though, the G string when fretted below the the 5th fret is very sharp. By the time you get to the 12th fret you are almost a semitone sharp.

All of the other strings intonate fine up and down the neck, so I'm really scratching my head on this one.

If this were a mandolin I would just compensate by angling the bridge, but this being a mandocello and thus the G string being one of the middle strings I can't really do that without pulling the low C out of tune.

Any help appreciated!

[UsuallyPickin]

Hmmmm … is the nut slot a hair high or the saddle a hair uneven, humped? I have read on a mandolin that can cause intonation issues. Otherwise … I am watching this to learn. Luck R/

[BeachMando]

The nut is filed super low. I should have mentioned that this thing actually utilizes a zero fret so I don't think the nut actually affects intonation in that case.

The bridge slots are super shallow though. I was considering filing them down a little to maybe create a little more slack on just that one string. I've never heard of this fix before though, so wanted to solicit ideas before attempting drastic action.

[lenf12]

Try a different string gauge for the G perhaps? File down the leading edge of the bridge to change the compensation? Just a thought...

Len B.
Clearwater, FL

[BeachMando]

I thought of trying that too, but unfortunately there is not as much selection for mandocello strings as there is for mandolin strings.

[lenf12]

Try acoustic guitar strings. There should be plenty to choose from.

Len B.
Clearwater, FL

[Pete Braccio]

Check if your bridge saddle is turned around.

Since the issue gets worse the more you move towards the bridge I would guess that's where your issue is.

[BeachMando]

Check if your bridge saddle is turned around.

Since the issue gets worse the more you move towards the bridge I would guess that's where your issue is.

Thanks, I did check this as one of the first things, was hoping it would be that easy!

[kurth83]

Show us a close-up pic of the saddle.

I have an OM with the same problem, and the bridge wasn't made for a wound A string.
And even with a PS A the compensation is still off for the strings I am using.

So I am having a custom bridge made, but first have to discover proper compensation.

This thread (where I discovered a way to find correct compensation) may help:

https://www.mandolincafe.com/forum/t...n-tool-perhaps

Also, I think you are right that if the action is too high for that string, that will also cause it to go sharp up the neck.

So you need a properly adjusted and compensated bridge (for the strings you are using) to fix the issue.

[BeachMando]

Show us a close-up pic of the saddle.

Thanks, that is good info. Will post a pic in a few hours when I'm home.

[bratsche]

That sounds pretty severe, and I suspect you'll need a new, possibly custom saddle. I have a very nice flattop mandola made by someone with impeccable credentials, but the bridge was just not right for the Thomastik strings that I favor - the D course was always noticeably sharp, although not to the extent of your G course. Since there was no room left on the bridge to file that part back the necessary 1/8" or so, I had to make a whole new ebony bridge (one-piece) properly compensated for these strings, and now it's fine. The old bridge is still in the case compartment, in the event that a future owner finds it more useful than my replacement.

bratsche

[BeachMando]

Thanks for all the replies so far. Here is a pic of the bridge taken from just behind it.

https://drive.google.com/file/d/1pcD...ew?usp=sharing

[BeachMando]

Quick update - I tried throwing on some .42 acoustic guitar strings per Len B's suggetsion above.

The strings that had been on there were allegedly .44s.

This made a pretty big difference. Intonation is now perfect to the 7th fret and "within spec" down to the 10th. The 12th still pulls a bit sharp, but I'm hoping after this I can just make some minor bridge adjustments to sort things out.

I'd like to avoid a full bridge replacement since 1) the bridge on this thing is wired as a pickup and 2) I got this on the cheap and don't want to pour a ton of money into it until I can figure out if I will actually use it.

Appreciate the help in this thread everyone. This is such a great community and site!

[Pete Braccio]

Looks like the compensation is way off. Those are all wound strings. The bridge should step up from the C (farthest towards the neck) to the A (closest to the neck) instead of the up-up-down-up pattern of you bridge. The G string looks like the saddle is shaped too far towards the neck.

It also looks like the D string is too far away from the neck. That should send that string flat as you move up the neck.

[HonketyHank]

That saddle is definitely compensated for two plain treble pairs and two wound bass pairs. I had the same problem with a mandola I bought. New saddle, properly compensated, solved a whole world of intonation issues.

[HonketyHank]

Here is a non-adjustable bridge on a 1920 Gibson mandocello currently listed on Reverb (NFI). Note the compensation steps. This is the step pattern I would expect when all strings are wound, even though it looks like the treble pair is plain steel (!) on this instrument. If so, I bet this one has a bit of intonation problems on the higher strings.