top, C17 clavichord; bottom, C18 clavichord
Sorry, I cannot supply instructions for the Clavichords.
The clavichord is of very early origin and existed for centuries alongside the harpsichord. Its tone is too soft to be used as an accompanying instrument but is much more sensitive to the touch than that of the harpsichord. for this reason it has been favoured by many musicians (the most fmous being CPE Bach) for playing alone or too a few friends – complete quiet being necessary for this enjoyment.
To make the clavichord still simpler, 'fretting' was adopted, that is, one string had to serve for more than one note. The different keys strike the string at different places. (In the clavichord, unlike the piano, the striker or 'tangent' remains in contact with the string until released; the sounding length of the string streches from the tangent to the bridge.) The disadvantage is that two such notes cannot be sounded simultaneously, but as they were only a semitone or tone apart this was not necessary in early music. Some say fretted clavichords sound better because of reduced string pressure on the soundboard.
The clavichord is the simplest of all keyboard instruments to make and also the cheapest. Being very small and quiet it can be the ideal personal instrument for someone living in a flat or studio. There are plans for two versions. The 17th century instrument is fretted (max, 3 notes per string) and has a "short octave" (as explained for the Flemish Virginal). Its compass is suitable for music up to about the middle of the 17th century, and a considerable amount of later music. The 18th century instrument is also fretted but with no more than two notes per string, The compass is c-f3 chromatic, so that much later baroque music e.g. J.S.Bach and C.P.E.Bach can be played.