I have just purchased a second hand acoustic guitar: a Sigma 000MC-15E. The strings it came with tune fine but the high e string sounds noticeably out of tune even when played just at the third fret! After reading on here I'm thinking that the string gauge was maybe changed considerably from how it was setup in the factory and so new strings of a different gauge may fix it?
But why is only the high e string affected? Is it just more noticeable on high e? Should I get heavier or lighter strings? The high e goes flat when fretted, so I reckon a heavier gauge will bend the neck more lifting the strings off the fretboard and therefore make the strings sharper when played fretted?