Tuning Question

I've read through the "I just got a dulcimer' document, and it was very helpful.  My question may seem redundant, but I want to make certain...my dulcimer is tuned DAd, I believe...do I need to change strings if I want to tune it DAA?  I'm very interested in the 'old' style noter playing, and reading through discussions it seems like DAA lends itself better to noter style.  Thank you!