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Re: Kurath/Willson F Tuba — Adding a 6th Valve

Posted: Tue Apr 11, 2023 9:06 am
by bloke
One of the big advantages of 6-valve tubas is that they offer multiple options for adding two whole tones (ie. "2-3") to the instrument's length:

> 2-3
> 1-2-6
> 3-6
> 1-5
and (if needed to be way sharper) even
> 5-6

These options are not going to be immediately under the fingers of someone new to 6 valves, and they are never going to become completely automatic to longtime players of 6-valve instruments, but they're there, and are useful for dialing in 2-3, which is probably the most squirelly valve combination on all valved brass instruments - just as 5th position is the most squirrelly trombone slide position. (1-3 or 4 is even more squirrely, arguably, but only involves two pitches, so...)

Having dealt with tuning problems on a bunch of tubas, I've decided that mouthpieces that offer less (so-called "slotting") or (thinking of it in another way) offer MORE "tuning flexibility" are better choices for instruments with more tuning issues. I tend to also prefer smaller mouthpieces with smaller instruments as deep mouthpieces (particularly with larger throats) seem to tend to "overwhelm" smaller instruments - often resulting in a type of sound that - to my ears - is too "covered". As far as pitch"favoring/lipping" is concerned, our decades of experience also tell us that it sort of goes out the window at extreme volume levels, as well as extreme upper pitch levels (ie. "way up there"). F tubas - with E-flat/B-flat size mouthpipe tapers and E-flat/B-flat valveset bores - are sort-of enigmas, as far is "what types of mouthpieces are best" is concerned...at least, in my experience.

Your theory about "where a valveset is located in an instrument" is a good one - because it involves WHERE the tapered bugle is absurdly distorted by a bunch of cylindrical tubing, but the taper of the cylindrical tube itself (and you know this) is also a big factor. Those computer programs (which take all of this into account) never find perfect solutions (as there are none), but can offer less-bad ones. Working with instruments which were designed prior to these programs having been developed is going to involve ingenuity combined with luck and - as these programs are far from perfect - ingenuity is necessarily going to be involved in recently-designed - so-called "computer-designed" - models as well, if we are to completely "dial in" intonation when we are playing (as modern recordings - to which laymen are exposed DAILY, on TV, nearly always offer extraordinarily superb intonation -
so we workaday/not-Heifetz-level musicians are now expected to meet higher tuning standards than was Heifetz himself :bugeyes: ) I clearly recall that very minor tuning issues (in the distant past) were met with just a little bit of nonchalance ...and none of this is meant to be rebuttals, but only agreements.

Re: Kurath/Willson F Tuba — Adding a 6th Valve

Posted: Mon Mar 18, 2024 1:32 pm
by the elephant
Okay, so I finally found this old thread. As with my other two (Holton and King) it is time for a necro-bump.

So this tuba also will be up for sale as soon as I finish it. I have to re-do some major work now that I have performed both a solo and a quintet recital on it and better know what I want.

Firstly, the 6th valve I ordered was bass-ackward from my final design. It was perfect for when I thought I would run the 5th and 6th levers over on the "off" side of the top bow (as with 6-valved rotary tubas) because I had intended to flip the 5th valve.

Well, I never did that. I retained the 5th setup and ran both levers where I thought I could access the 1st slide with minimal movement of my left hand. And that left me with this valve that was exactly backward of what I needed. Keep in mind that both these valves have stepped bores to remove a sudden expansion of the horn's bore that had to be accomplished using some hinky methods that Herr Kurath later fixed when he introduced the ROTAX 5th valve.

This means neither of those two rotary valves could be flipped to reverse the direction. I was stuck with a righty and a lefty when both needed to be identical. It did not matter to me which direction they faced, just that the stems were together to facilitate the lever linkages.

SOOOOOooooooooo……………

I bought a new 6th valve and all the junk needed to make a new slide circuit and braces, and now I have to remove the rotor section and swap out said 6th valve, build a slide of the correct length that fits in the new space (much more complex, unfortunately) and then rig up a new link arm to the lever (which will be much simpler, thankfully).

Once that is done I will clean it up and put it up for sale. I will not go into the gratuitous detail work I would have done had this remained my tuba. No need. No one cares about that level of detail when it adds to the price.

Anyway, this ought to be a pretty darned cool tuba for someone to buy from me, once it's on the market.

Be gone, fell linkage of Satan! Thou doth vex me sorely! HAHAHA!!!
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