Bass String Buzz @ 1st & 2nd Fret
Instruments- discuss specific features, luthiers, instrument problems & questions
Something I learned recently is that the slot in the nut should not be flat. It should come to a little point, so the string sits in a single point rather than resting on a level surface. In other words, the slot looks like a V if you look at the nut from the string's point of view, but if you look at it along the nut itself, the slot inside should look like a ^ rather than be flat. If a string sits along a flat ledge inside the nut, it can move around and buzz.
I have a nice small dulcimer that had a buzz on only one string and it was driving me crazy, but as soon as he heard it, the repair guy at a music store diagnosed the problem. He took about ten minutes filing the slot to increase the point, and the problem was solved.
I'd be surprised, though, if McSpadden made that mistake in the original build.
And I should also say that I sometimes get a buzz on strings and I'll just change the strings and the buzz goes away. I can't explain why older strings would buzz, but it's such a simple fix I've never worried about it.
Your string gauges seem reasonable to me. I use 26", 16" and 13" on my 25" VSL dulcimer tuned DAd.