A Dictionary of Music and Musicians/Combination Pedals
COMBINATION PEDALS (Pédales de combinaison) are an ingenious modern French invention originating with the eminent firm of Cavaillé-Col. Instead of operating upon the draw-stops they act upon the wind-supply, and in the following manner. A great organ contains, say, twelve stops. The first four (1–4) will be placed on one sound-board; the next four (5–8) on a second; and the remaining four (9–12) on a third sound-board. Each sound-board receives its wind-supply through its own separate wind-trunk, and in that wind-trunk is a ventil which when open allows the wind to reach the sound-board, and when closed intercepts it; which ventil the organist controls by means of a pedal. The advantages of the ventil system are, first, that instead of the stops coming into use in certain fixed and invariable groups, any special combination can be first prepared on the three sound-boards, and then be brought into use or silenced at the right moment by simply the admission or exclusion of the wind. Moreover their action is absolutely noiseless, as it consists in merely opening or closing a valve, instead of shifting a number of long wooden sliders to and fro. The objection has been raised, that in the ventil system the stops no longer 'register' what is about to be heard; and the extreme case is cited that every stop in the organ may be drawn, and yet no sound respond to the touch if the ventils be closed.
[ E. J. H. ]