Posted by Klaus on July 16, 2001 at 08:16:37:
In Reply to: Re: Re: Re: Re: Re: Does anyone know what this horn is? posted by Lew on July 16, 2001 at 06:59:17:
Hi Lew
Somehow I have got the impression, that you are working with brass repairs and modifications. Which I am not, apart from ergonomical add-on’s made out of anything but brass. And then of course my backbore openings and adapting of adaptors.
Still I will air my reservations against putting larger receivers on narrow leadpipe instruments like the older Bessons.
Technically this can be done. Of course. But this will not expand the leadpipe at the connection point.
My sense of destructive turbulenses gives me the chills at the thought to play from a large bore stem trough a large bore receiver into a small bore leadpipe entrance.
We have to accept stepwise changes in bore, even reverse such ones, in valve slides and main tuning slides. But a sudden reduction of bore right out of the mouthpiece is a very bad idea.
I will allow myself to take examples from outside the tuba sphere. I have 7 instruments with tuning leadpipes. A construction system that I hate from the bare principle. Only it is inavoidable in some instruments.
The first one was a Besson Eb cornet. At first I realised, that sound and feel both were open for improvements. I hate stiffness in legato. The main factor of course was on my side of the mouthpiece rim. But I am enough of an equipment freak to look out for optimations.
Right out of the Besson tradition the tuning leadpipe was made of a quite heavy walled tubing. So I undercut (or is that chamfered) the leadpipe opening towards the instrument.
The immediate bonus was a much freer blowing. And the undesirable sizzling overtone components were gone as well.
Since the I have done the same thing to a piccolo trumpet, a corno da caccia, an Eb flugel, and 3 Bb flugels (modern Yamaha, modern B&S rotary, and ancient Zelenka rotary). Never regretted.
And these samples were about taking the steps out of increases in bore close to the mouthpiece!
Rather than introducing a stepwise reduction in bore by mounting a new receiver, I would try to get a new leadpipe from a 994, which has the same bore at the entrance into the valve cluster.
Klaus