This is one of only two double tubas in the collection.  One difficulty encountered when designing a double tuba is the extra length of the instrument that must be provided for when changing between F and BBb.  If the added tubing is of too small a bore, or of too little taper, then the BBb side will play like an F tuba with far too many valves down.

On this tuba, the designer tried to compensate for the taper difference somewhat.  This required an extremely large second change valve, which can be seen inside the bottom bow of the tuba.

This unique instrument is an example of what is known as a “full” double instrument.  This means that the airstream travels through the F-side tubing when the tuba is in normal use.  Upon activating the change valves, the airstream is diverted to a completely different second set of playing valve loops.  As the airstream only passes though the playing valve set once, this provides a freer blowing air-path through the instrument.  The disadvantage of a full double is that the instrument must possess full-length BBb-side slides in addition to the full-length F-side slides.  All this extra tubing creates a heavier instrument to carry around.

The full double system is currently in wide use by french horn players in the Bb/F double horns in common usage by professionals today.  It is interesting to contrast this “full” double instrument with what is known as a “compensating” double tuba, represented by the Lehmann double tuba #200312 that is also displayed and described in the feature collection.  The “compensating” double system is currently in wide use by euphonium players to enable them to play in tune in their lowest register.

Tag #: 00687
Serial #: 52557/52511

Bell Diameter	Bore Size	Height
17.0″	.655″	35 3/4″

Comments:

“J.W. YORK & SONS / GRAND RAPIDS / MICH.” on bell. Ornate floral engraving on bell.