Same gauge strings, all in correct place. But now a slight fret buzz. Very annoying. Most folk don't notice but I can hear it like a band saw. I'll get myself some decent quality strings and see if it helps. If not then I'm concerned.
I've used 11's on it since I bought it, although it had 12's on when I got it (about a year and a half ago), which I changed within days. Should I go back to 12's?
I think if you've played with 11's for 1 1/2 years you'll be ok stayin' with 'em. I'll bet new strings will solve your problem, but if not....
Take a good close look at your frets ( 1-5 ) and see if there are deep grooves in the frets. As the grooves deepen the string (s) become closer to the frets further up the fretboard, thus causing fret buzzing. You might need a fret job. The guy that does all of my guitar does partial fret replacements( replaces only the ones that need replacing). Most of the big named music stores won't do this. It's all or nothing with them and that's B.S.. Call around and find someone who'll replace the bad ones only.
If the frets look ok then have a look at the nut ( too deep=buzz). Or have a look at the saddle in the bridge and make sure there are no cracks or deep grooves. I stop at this point and take my instruments to my repair guy. Precision is crucial in nut, bridge, and/or saddle repair.
How often, and how many hours per day do you play this guitar?
Peace and Guitars,
Give everything but up.