Tangents have been positioned for a tuning in quarter-comma meantone. This means that tangent positions will be in the middle of the keys for the lower frets.

For a discussion of this choice see Clavichord International Vol.10 No.1 May 2006, pp. 17-20: HansErik Svensson, Comments on the tuning of some fretted clavichords in the Stockholm Music Museum.