cimbasso valveset bore

[imperialbari]

From which tuba model does a 6-valve block with a uniform .750" bore come?

[imperialbari]

So you going for this sound:

[UDELBR]

On mine, the length of tubing between the mouthpiece and the entry into the valve block is staggering.

I'd always wondered why some cimbasso makers do this: make such a loooong leadpipe. On tubas, a shorter leadpipe makes a more direct sound, which is what you'd want on a trombone-like instrument, right?

[Jay Bertolet]

I'd always wondered why some cimbasso makers do this: make such a loooong leadpipe. On tubas, a shorter leadpipe makes a more direct sound, which is what you'd want on a trombone-like instrument, right?

I wondered the same but then it occurred to me that a trombone is basically the same as this cimbasso design. The slide is an approximately similar length of tubing before the valve (if any) and then the bell section. I wonder if it has anything to do with the more cylindrical bugle profile. Maybe that whole longer/shorter leadpipe thing we see on tubas only works the way we know it on conical profile bugles.

[imperialbari]

I agree about the profile of the pre-valve-block tubing being more significant than the length of that tubing. Even if it may be long, the conical leadpipe portion may be short.

Dual bore cylindrical instruments are no novelty. The phenomenon is seen in tenor and in bass trombones with conical slide crooks. My own three samples happen to be from the upper end of the brass instruments' spectrum. A Scherzer Bb trumpet has the rotary valves in the branch opposite the bell after the conical main tuning slide. A Pfretzschner F alto trombone has a huge .500"/.547" dual bore, where a Conn 36H Eb alto trombone has a .491"/.500" dual bore before the Bb valve.

I only disagree with one aspect of bloke's plan. I wouldn't want to have the bore expansion happen at the entry into the valve block. I would want the waves getting a chance to stabilize before entering the problematic interiors of any rotor block. A conical bottom bow is harder to find or make than a cylindrical one, but then the expansion may happen before of after the main tuning slide. Which after all hasn't to be in the bottom bow. An inserted loop like with the 3rd valve slide of a YBB321 also would work.

Klaus

[roweenie]

Joe,

Did you ever get around to building your cimbasso? Did you use piston or rotary valves?

I'm in the planning/execution stage of building one, and I'm curious to see how you set up your leadpipe. (I'm not sure whether I should build it with a traditional tuba leadpipe, or maybe something more cylindrical).

Any photos of leadpipe set-ups from other cimbasso player's horns would be also greatly appreciated!

[roweenie]

Will the smaller set be piston or rotary (or is it classified information )?

Mine will have the venerable King .689 valve block as its valve nest. I'm just a little stymied as what I should be doing with the leadpipe (tapered with tuba receiver, cylindrical, etc....)

[Donn]

Trombones are of course cylindrical, since you're basically sticking the mouthpiece in the slide and the slide has to be cyilndrical. So to make it work out, they put a receiver "leadpipe" inside the tubing that incorporates some of the bore profiling that we get with a tapered leadpipe. And I gather the fancier trombone models (unlike mine) give you the option to easily replace that "leadpipe" with another one. If there's a contrabass trombone model for which you can get leadpipes, then it seems to me the ideal thing would be to bring your external leadpipe down to a sufficiently long straight section with the internal diameter that matches those leadpipes, and then you can just try out leadpipes and pick the one that suits you the best. (I don't know jack about this stuff, though, so take that for what it's worth. It occurs to me that the long straight receiver might be a bit of a problem!)

[PaulMaybery]

Hi Joe. Interesting project and one that might have some after-market value. Worked with a friend this summer, Steve Call from Utah. (Steve, Chuck Schulz and I did a novelty Cimbasso Trio) Steve has several Cimbassi. One in particular is Italian, Rampone & Cazzani I believe. I realize you are working on a project in F (Jinbao of which I happen to have one as well - so am familiar with its bore size at around .730.) But some thought on the narrow bore: Steve's cimy is in BBb and has a comparatively small bore. While I did not measure it at the time, it seemed about the size of a F Contra bass trombone, that being just under .600. The bell section was more like a euph with the double wrap. I'm sure the larger bell taper etc had something to do with giving it a fair amount of sound and resonance. My thoughts and intuition would be if you went that narrow on an F cimy, it would probably be rather tight sounding - maybe even stuffy. But it may on the other hand give it a timbre closer to a slide F contrabass bone with around .600 bore . If you are using a .730 valve set I would think the narrow bore from the MP be ahead of the valves in as 'long of a length' as possible, (with the valves as close to the bell joint as possible - more or less mimicking the slide of the F contra (the F contras that I have tooted had a dual bore with the second slide slightly over .600 /@.6.20. I get the idea somehow that the .730 bore of the Jinbao F/Eb cimy is intended to approach the sound of the BBbs but with the modern flexibility of the F. I suppose were I to try a similar project I would try to get as close to the F contra lead pipe and slide before entering the valves. How much taper on the tube just before the valves, would probably take some trial and error. Would a series of step ferules work as a preliminary method for getting into the ball park? (or simply telescope the tubing) Would love to hear how this all progresses. Am I correct is assuming you are trying to get closer to the slide contra sound?

[vlatuba]

I've finished the bulk of the work on a cimbasso valve section that can be attached to a Kanstul contrabass trombone bell. It's actually now a convertible contrabass trombone in F/cimbasso in F or E-flat.



I used a Conn 5J tuba valve section, .658 bore (thank you, Marty Nielan). I ended up turning the valve section 45-degrees as the original layout would have been excessively uncomfortable, a process that added far more work than I had planned on but the results are positive. I had to make several 45-degree knuckles and then needed to bend straight tubing to make the 1st valve slide. Good practice for both my silver soldering and tube bending skills... The only disappointment is a possible water collecting dip in both the first and fourth slides right near the valve cluster. I was able to avoid that problem on the third slide, but the 1st and 4th had curves in the tubing just too close to the piston casing to cut safely.

It plays quite well and is comfortable to hold. The pistons are fast and a real treat compared to the Hagmans on the Haag I use at work - those fast Verdi licks are far easier. I deliberately made this instrument to sound more trombone-like (the owner will be using it primarily in a trombone ensemble) so I went with a smaller bored valve section (only .009" bigger than the Haag) and tried to avoid tight curves as much as possible. The owner wanted an instrument in E-flat but the instrument would have been too long for the player to sit in a chair if straight so it needed a loop somewhere. I took advantage of that need and made the instrument dual pitched in either E-flat or F, by putting the main slide either in or out of a loop.

I put the valve section just off the leadpipe, unlike any other piston cimbasso I've played, to no ill results. I wanted the valves in a similar placement to most rotor valve instruments. I also wanted the bell closer to the player (I have both a Haag and a Melton E-flat at my disposal - the Melton bell is so far away from the player that I feel quite disconnected from what is coming out of the bell while the Haag is set much closer, like a trombone bell would be). The lead pipe is an Allied universal with a standard tuba mouthpiece receiver. It may not be Ideal but seems to be a decent starting point.

It's being test ridden by the owner for while so we can make any adjustments before I clean it up. It'll be getting more water-keys and a a fifth valve once I find one suitable for it.

There are more detailed pics on my website:
http://www.diefesbrassrepair.com/216221798" target="_blank" target="_blank" target="_blank

Cheers, Ed

[imperialbari]

Interesting approach!

How does it work with the Kanstul valves sitting in the bell?

Any extra valve combinations potentially making a fifth valve obsolete?

Klaus

[vlatuba]

Actually, I made the original trombone valve section removable and have a straight section that goes in its place, so it can't be used together. The bore on the contrabass trombone is quite a bit smaller up to the main tuning slide, and al least the first trigger is far too small to use with cimbasso (something like .620, as I recall).

Ed