JP7 low B string intonation problem

[jaad75]

I finally have my JP7 - it's probably the best guitar I've ever played, I love the way it looks, sounds... everything... There is just one thing: I have a problem with setting up the intonation for 7th string. Open B is perfectly in tune and 12th fret B is about 10 cents sharp - it makes the other tones slightly out of tune. I cannot make the string any longer - adjustment screw is tighten completely... All the other strings are perfect. What should I do?

 

[jongitarz]

Try a new string, and use the neck p/up when you intonate

 

[jaad75]

I'll try a new string tomorrow - I hope it's gonna slove the problem. Thanks.
BTW, what is default low B string gauge for JP7?

 

[jongitarz]

.056

 

[jaad75]

thank you

 

[jeffrey]

As a side note, I had a similar problem on my D string on my JP7.

It turned out there was a small piece of material in the nut slot hanging over the first fret maybe 1.5mm or so. It looked like when the slot was cut all the material wasn't removed.

What this does is change the point at which the string leaves the nut therefore changing the intonation point of the saddle. I had trouble getting it to intonate properly until I noticed that.

I took an Xacto knife and knicked it off and it intonated just fine after. My other JP7 had no such problems so it was most likely a fluke.

Something else to look out for maybe...

 

[jaad75]

I've changed the string and it's much better... Almost perfect, to be honest... But what will happen, if I decide to set the action slightly higher? I have no room to move the saddle back... Is there any way to adjust it?

 

[jeffrey]

Setting the action higher shouldn't change your intonation much if at all.

 

[jaad75]

I can imagine that with higher action the string is slightly bent before it touches the fret, so fretted notes sound a little sharper - am I wrong?

 

[jeffrey]

It's got nothign to do with the height of the action really unless you jack it WAY up. Like high enough to play slide or something.

But I can't see raising it a reasonable degree (ie: like something you'd do on a JP7) making any difference in intonation.

I run the low B fairly high on both my JP7's so I can beat the crap out of it without it fretting out. I've got no intonation problems at all.

 

[jaad75]

As I said before, with new string I don't see the problem also... I'm just curious, because there is no room to make the string longer anymore, and maybe there is a way to adjust something and get more space (just in case)...