I forgot about this: mountaindulcimer.ning.com It is mostly lap dulcimer, but the same concept applies. Especially look for videos by member Guy - he's a real artist on a dulcimer! They are so far beyond what I can play, but I've watched them lots and will watch them more and someday I'll give his tunes a whirl. They are very nice folks!
Some folks build dulcimers with two melody strings for a bit of extra volume. And is, obviously, has a four string head. I think Bone builds all his that way. And Old Lowe, too. I play melody over all three strings, so if I am pairing, I'll pair them all!