LaBella 17 intonation issues

[Ethan Schwartz]

I gotta get to the bottom of this or it will drive me crazy.

So some time ago, I got a cheap modern open-back (5/8" bridge, ~3 degree neck angle, zero nut, etc). It came with cheap steel strings and the intonation was great up and down the neck. I then put on LaBella 17s. The 3rd and 4th strings intonated correctly. But the 1st fretted slightly sharp, and the 2nd fretted waaay flat. I even tested it with a tuner (12th fret vs. harmonic). My ears were not deceiving me. Some time later I put on a 11/16" bridge, thinking maybe this is some fluke of geometry. Nope, no difference. Steel strings went back on, intonation is fine.

I very recently came into possession of a proper turn-of-the-century instrument. It came outfitted with lightly used LaBella 17s. Same exact issue. The 2nd string must have been fretting ~25 cents flat around the 12th fret. 1st string was fretting ~10 cents sharp. No issues with the 3rd/4th/5th. I changed those out with Nylguts...problem went away. 

I can suggest no explanation for this other than bum strings. But the fact that two different sets of strings on two different instruments had the same issue...I really don't know. And I'm not about to buy a bunch of packs of LaBella 17 just to test it out. I'm wondering if anyone here has encountered something similar with LaBella 17s (or other nylons). 

[Joel Hooks]

That is strange.  I have used countless sets of Labella rectified nylon on many different makes of banjos and have not had any problems. I am even using them on my Spanish guitar with no issues.

[David Connelly]

This is very similar to a problem I posted recently. It was labella 17's and it went away when I replaced them. It just so happens that I replaced them with Nylguts. Gratefully Jodi and Joel helped me out in the forum.  https://classic-banjo.ning.com/forum/topics/intonation-problem

I currently have a bunch of different gauged Labella singles that I am going to be trying out.

[Joel Hooks]

If you are getting false strings from Labella they should know about it.  Since they are rectified there should not be a problem but I suppose it could happen.  I would contact them via their website and let them know.

You can check for false strings a couple of ways.  A good pair of calipers with measurements all along the string is one way.  I'll dig out and post an article on another way that involves pulling the string tight and watching the waves so see if they are even.