A string problem

[littledonnie]

I have a mandolin that has developed a strange harmonic or over tone on the a string. I've tried new strings. It has a piece of leather to dampen the strings at the tailpiece. Any ideas?

[bradeinhorn]

is it a different string gauge than normal? sounds like a bridge or nut slot issue.

[markishandsome]

It's hard to say without knowing what you mean by "strange harmonic or over tone". Is this a ringing that occurs wherever you fret the A sting, or is it just in one or two places? It could be your piece of leather is not making good contact with the offending string. You may need a second piece of leather between the nut and the tuners to dampen sympathetic vibrations back there. The string could be buzzing around in its saddle slot. A pickguard screw may be loose and rattling around. Can you describe your problem a little more?