Quint valve slide extensions for Alex 157 6v F tuba

[arpthark]

Some fun parts arrived in the mail this afternoon. My Alexander 157 is a wonderful instrument, but the fifth valve was unusually tuned to a perfect fourth length -- useful in some scenarios, but there was no reliable way to get an in-tune low Bb, which is of course a very common note.

I am so grateful to Jake @TheBerlinerTuba for cutting and facing this tubing and sending it across the pond from Germany to extend the fifth valve to be a quint valve. Somehow, my math was accurate and it works really well and doesn't collide with the bell ("in tune" position has the slide in farther than the pic below, so there is a bit more clearance than shown).

I will need to mess around a bit more to figure out the most in-tune fingerings for low Ab, G, and Gb, but everything else is fairly intuitive (sixth valve is a normal flat half step). The quint valve also provides a very useful alternate for other B-flats around the instrument, which generally tend high on my horn.

[York-aholic]

Will it eventually get some braces between the nickel silver outer? Or are you going to be extra careful? Heck, maybe both!



I like it!

[bloke]

How does the additional mass affect the tone?

[arpthark]

Will it eventually get some braces between the nickel silver outer? Or are you going to be extra careful? Heck, maybe both!



I like it!

Yes, the plan is to solder the brass inners in place within the nickel outers, and then brace everything up. And also be careful!

[York-aholic]

One more question: do the brass inners go up all tge way to meet the inners from the slide crook, or just go into the nickel outer enough to solder?

If the later, what are your thoughts or the expansion then reduction of the bore on each leg?

That expansion/contraction is there every time we pull a slide out from ‘all the way in’.

I don’t have an opinion on it yet, just curious as to others thoughts on the matter.

[arpthark]

The legs are just long enough to solder into the outers.

I've noticed a slight difference in response in the upper octave B-flats, but it seems fine for the lower one. I don't think I'm picky enough to know any better.

I did play around with the idea of having very long inners, and just a small sleeve of the outer nickel, but I think this looks better.

[bloke]

If you are particularly concerned, of course there are those detachable brace thingies that whereby you could brace it to the body.

If any of the places that you can brace it to the instrument itself are close, those ybb 641 detachable braces would really blend in.

[MikeS]

It appears that you are in good company with this plan.

https://hornguys.com/products/alexander ... uint-rotor

[martyneilan]

Cerveny was putting a kaiser bore quint valve on their little F tubas decades ago. Almost making it a double tuba in a sense.

[arpthark]

Yeah, not quibbling with Marty but more the Horn Guys -- not sure if it really qualifies as a "double tuba" in F/BBb any more than an F tuba with the fourth valve depressed qualifies as a double tuba in F/CC. It isn't as if you can just use BBb fingerings with the fifth valve down. That ad copy struck me as odd.

But, yes, this system definitely has its advantages, and my extension sort of has a larger bore since most of the tubing in the extension is the 20.5mm outer nickel silver tubing.

That fingering chart is a big help!