A full double tuba in F/BBb

Abstract

Described here is a design for an F/BBb tuba. The valves and keys needed for a full double tuba take a lot of space. There exists a full and complete double tuba in BBb/EEE built on a very large instrument frame and is more than 5 feet tall and 2 feet wide [1]. However, the sizes of F tuba frames are too small to accommodate 5 double and 2 switch valves and their associated tubing. Using a standard F tuba frame, the lack of space has been solved by having four double valves and two switch valves. The fourth double valve is unusual because it is descending on the F side and ascending on the BBb side of the instrument. An ascent to a BB □tuba is made by the ascending part of that valve. The valve slide lengths have been optimized to yield intonation such that −5< intonation error < 5 cents over a five semitone descent from an open note. Various acoustic measurements are reported for the instrument which will be exhibited. [1] F. J. Young, “Five valve compensating brass wind instrument,” Proc. Meetings Acoust. 11, 035004 (2011).