Last week I bought new strings for my mountain (lap) dulcimer. I use three strings, and the package contains strings of three different thicknesses. The gauges, from high to low, are .012, .014, .022. (These are d'Addario strings.)

Many people tune their dulcimer D-A-D, but I use D-A-A. Should I be buying strings in only two gauges, one for the low D and two the same for the A's?

Does the thinnest string wear out faster? Or is it in a better position because, being thin, it doesn't need as much tension to reach pitch?

I like my dulcimer to sound as rich and mellow as possible, not thin and twangy.