Why would the same string keep breaking? I service a Kawai upright model NS-20A made in 1991. The longer wound string for F21 has broken repeatedly the last few years--always the same string. The hammer seems perfectly mated to the strings. I lightly filed the bar in case something was kinking the string there, so we'll see if that helps. The piano otherwise seems to be getting looser. It doesn't hold its pitch as well as it previously did. And its plastic dowel capstans are so loose that I need to frequently adjust them. I service the piano at least yearly, sometimes more often. Perhaps the answer to all this is that it is a school piano. As school pianos go, it does receive good care. Maybe someone with NS-20A experience can weigh in with similar or contrasting results. Arlie Rauch Glendive, MT
This PTG archive page provided courtesy of Moy Piano Service, LLC