Posted by Art on April 15, 2001 at 08:47:35:
In Reply to: Sousaphone cut to CC posted by Matt G on April 13, 2001 at 13:08:12:
One possibility is to start with a junk BBb sousaphone that has a tuning slide at least six inches long. Remove the bell, remove the last bend before the bell, and replace it with a small straight bell, perhaps from an Eb tuba. That will give you sort of a goofy-looking helicon in BB natural. If you think it may be acceptable, then find a way to shorten the leadpipe, arranging it so that no mouthpiece bits are needed. That can bring it up at least another 20 to 25 cents. Then remove most of the telescoping tubing from the tuning slide until the horn is in CC. You'll have to do that in small steps because you won't have a lot of adjustment left in the slide. If you have parades on cold and warm days you will need all the pull you can get. (Maybe you can fix the leadpipe so that it can be used either with or without a bit.) If the result seems to be usable then start shortening the valve tubing. Each one will have to be reduced to approximately 89% of its original length.
You could also stretch an Eb sousaphone down to CC and end up with something that looks like a sousaphone, but it will have a blatty low register because of all the added cylindrical tubing. Good luck with the project, and be sure to let us know how it turns out!