Here are some details:
(1) It's a Takamine, about ten years old, and it's never had a high quality case for a home. It's been in a cheap case that's not a good fit and even this case has been broken by my kids so I've had to use a wadded-up cloth for neck support. So the neck could be warped, but I don't see visible signs of it.
(2) I just started soloing this summer, so this is the first time that I've actually ventured up around the 12th fret in a hammer-on kind of way. Could it be that the guitar has always done this and I just never noticed it, because I usually just play open chords? Any Takamine owners out there?
(3) I replaced the strings on it a few weeks ago, and bought a brand that I've never tried before, but the salesman assured me that they were quality strings, comparable to the John Pearson's I usually buy. Besides, they sound great apart from the 12th fret thing. I'm an old hand at stringing the guitar, so I don't think the problem is in my technique.
So my question is, why the buzzing only at 12th fret and higher? And what does it mean that it occurs mostly with hammer-ons? Has anyone had similar problems? I can't afford to get much work done to this guitar. I've read some old threads and heard about Jon's sandpaper trick, but this happens with all the strings, not just one. Any other suggestions? I know, I know: take it to your local music store . . . but I thought I'd ask here first. Thanks,
"It's all right son . . . we told you what to dream"