In Clavicordio vol 1, John Barnes gave a 3 page Reconstruction of Douwes
Clavichord and a scale drawing.
According to Barnes the instruction produces an instrumet 46" x 12
with projecting keyboard. Douwes remarks that red and yellow strings are
used Douwes inch could be 25.12mm (grant O'Brien) or 24.8mm (Praetorius)
. The first yields: c3125.6 c2 256 cl 435.5 tc 620 C 716
at a pitch of a= 425.
This instrument is triple strung. Barnes thinks this is Douwes normal
clavichord and the scaling mostly agrees with Grant O'Briens's scheme of
4 1/2 foot Ruckers at quart pitch suitable for all brass strings at A 440
(which I have tried)
I have never tried building one of these clavichords but feel
Barnes put some good thought into this.
Apparently Douwes chose not to give clavichord string lengths only 5, 4,
3 voet clavichord lengths.