The keyboard compass of all four Harpsichords is five octaves, FF-f3, 61 notes. There are three registers: 1 x 8ins., 1 x 4' on the lower manual; 1 x 8' on the upper manual with a shove coupler. A buff rail is provided for the principal 8'stop. Polished brass hand stops are provided to engage the buff rail and the registers. As options, the 1764 Goermans/Taskin and the 1769 Taskin may be equipped with a fourth register in peau de Buffle as well all models may have their ranges extended by 2 notes in the treble to FF-g3, 63 notes. The instruments have transposer blocks beside the keyboards so that both low pitch (a'=415 Hz) and modern pitch (a'=440 Hz) are available.
The cases are poplar with spruce framing and white oak wrestplanks. The soundboards are European spruce. The natural keys are covered with ebony and the accidentals are stained Swiss pear or ebony, topped with cow bone. The jacks are Swiss pear with holly tongues. Leather covers the upper and lower guides.
The cases are painted with one or two colours and decorated with wide gold bands and moldings. Trestle stands with square tapered legs are provided. Table stands with either cabriole or turned and fluted legs are available as options. The soundboard paintings and surrounding borders as well as all other laquered, or gilded chinoiseries are executed by Olga Tomlinson K.