Posted by Steve Inman on December 30, 2002 at 16:55:42:
In Reply to: Re: Re: New miraphone CC question. posted by Tim on December 30, 2002 at 16:16:12:
Well . . . . here goes the detailed explanation that I tried, oh so hard, to avoid in my previous post:
When you activate 4th valve, you now have effectively a GG tuba. And the tuning slides for valves 1,2,3 are the right length to lower your pitch by one, 1/2, three semitones, respectively, for a CC tuba, NOT for a tuba pitched in low G. Each tuning slide is too short by itself, and when you combine them, things get even worse. SO the "flat 1st valve" tuning is really a 1st valve tuning for a "low G" tuba with the proper length tuning slide. The 2+3 5th valve (actually a "flat 3rd valve) gets you an in-tune 1+2 note (or 3rd valve only note) for a tuba effectively in the key of low G (i.e. with 4th valve depressed).
So if you pull the 4th valve slide, you'll have to pull it a different amount for each note combination all the way down to low D (on a 4V tuba). This, because each combination of valves has a different amount of sharpness. So I'd end up having to continually have to re-adjust the 4th valve slide. It might be possible, but practically, it's less easy to reach on the back side of my horn (I think), and I'm not much of a slide-puller anyway.
But your idea isn't too far off, as many players will install some sort of mechanism to "kick out" the MAIN tuning slide when needed. You'd still have to continually re-adjust the slide, but you could design the kicker mechanism to be easy to reach/control. However, once again, this is more difficult/complicated with any tuba where the main tuning slide moves parallel with the ground (back-and-forth like my Miraphone) rather than up/down.
Steve "this phrase for rent -- Rick let me know what to insert! ;) " Inman
Kokomo, IN