Bad intonation?

Oliver

I don't know if "intonation" is the right word in English, but my guitar (Dell' Arte model Angelo Debarre) is really out of tune at the 12 fret. This happened right after i changed strings (Argentine loop end 0.10). When i have old strings on my guitar the intonation is quite off, but it usually fixes itself when i change strings.
The last time i changed strings it just got worse. I have of course tried moving the bridge but i can't move it enough to fix the problem. Does anyone have any tips that might help dealing with this problem?
I live in Norway and the temperature out side was quite extreme this winter, but my guitar survived it. I use an air humidifier i my case.

Thanks for answers. Oliver.

Elliot

Hmm...no answers yet?

Oliver, there are a few things that could be the cause, but here's a really good article:

http://www.wikihow.com/Set-Your-Guitar's-Intonation

Jeff Moore

You didn't give a lot of info on the problem. Intonation is the right word for this.
Is it one or two strings that don't intone when the others do? If so, the bridge is cut wrong, however on a good quality guitar that is unlikely.

If all the strings are out of tune up the fretboard it has to be that you haven't found the right spot for your bridge. You should at least be able to get the high E and low E perfectly intoned by moving the bridge, even angling it so that the low and high string slots (where the string touches the bridge) are in exactly correct spots for intonation. What I'm getting at is that the irregardless of where the moustache ends indicate placement of the bridge, you put the bridge where the guitar is intoned properly. It may look off, but aesthetics come second right?
Sometimes the bridge will be so tight between the moustache ends that you have to sand one or both ends a little just to be able to adjust it. If you sand one end or the other keep in mind that you should consciously choose which end of the bridge to sand, or both, if you want to adjust the alignment of the strings to the fretboard edges.
If your only sanding a micro amount, this doesn't matter.

No matter what, there is a spot that the bridge can be placed that will intone the low and high E. Once you have that spot, the other strings should be real close, IF, your bridge was properly made. When you get the high and low E to intone perfectly you'll find out how well your bridge was cut. If at this point all or even one of the middle four strings are still unacceptably sharp or flat, your into a problem that is beyond a forum response - You need bridge work that takes experience (judgements and trade offs made in a logical sequence that isn't a paint by number set of instructions) and not just words on a page.

Get the high e and low e going. Can't think of any reason you wouldn't be able to do that. Then you'll know where you stand with the bridge you have. Or use the instructions from the previous link and use a screwdriver to adjust your bridge?