Re: Re: Re: Re: Compensation system


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Posted by Chuck(G) on August 02, 2001 at 23:06:18:

In Reply to: Re: Re: Re: Compensation system posted by Lew on August 02, 2001 at 17:58:54:

Allow me to add a few words to Lew's good explanation.

When the last valve on a compensating instrument is pressed, the air is redirected through the valves to add tubing to lengthen the slides to conform with a lower pitched instrument. Thus on a 4-valve compensating Bb euphonium, when the 4th valve is pressed, the pitch of the euphonium is lowered to F and slides 1-3 are lengthened to the extent that they are about the same length that they are on an F tuba.

This is sort of a poor man's double tuba; the primary disadvantage is that the additional twists and turns of the airstream brought into play with the compensating system makes for a very stuffy low register. And the very lowest note will still be somewhat sharp.

Before WW II, Besson made compensating instruments as part of an "enharmonic" system, where the first slides were bypassed and a completely different set of slides brought into play when the compensating valve was depressed. The big disadvantage, other than having to tune a second set of slides, was the weight added to the instrument by this system.

There are several manufacturers (Gronitz, Alexander) of full double tubas, much the same as the double horn.

An extra valve or two can usually increase the number of alternative fingerings on non-compensating instruments.

The best of luck to you in your search!


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