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Bore Size of a Conn 36J?
Posted: Mon Jun 18, 2012 10:54 pm
by Gilligan
Any one know what the published bore size of the 1920/30's 36J was?
A friend has measured his horn at .770 in the valves but the valves are so close to the leadpipe that I suspect that this isn't the true designed bore.
Re: Bore Size of a Conn 36J?
Posted: Tue Jun 19, 2012 12:57 am
by Rick Denney
Gilligan wrote:Any one know what the published bore size of the 1920/30's 36J was?
A friend has measured his horn at .770 in the valves but the valves are so close to the leadpipe that I suspect that this isn't the true designed bore.
.770 is correct for the 2xJ series, and probably also the 3xJ series (though "1920's/30's" describes two different instruments) The related sousaphones were .730 bore, as I recall.
3/4" is the pretty standard size these days, and that's only a touch smaller than what you measured.
Rick "who measured a Conn 20J at the same value a few years ago" Denney