A five-string fiddle looks almost identical to a standard four-string instrument until you look at what the extra string tension does to the top’s overall load.
The added C string doesn’t just mean a wider nut and an extra peg — it shifts where the top needs stiffness to keep the whole string set balanced in volume and response. We adjusted the bass-side bracing on No. 39 specifically to support that extra string without over-stiffening the rest of the plate, which would have flattened the tone across all five strings just to accommodate one.
It’s a small structural change on paper that took most of a week of voicing and re-voicing to actually get right.