Playing Report:
Okay, so I recently performed a solo recital on this tuba, and am currently working up a brass quintet recital, so I have spent hundreds of hours with a tuner, metronome, drone pitch generator, and every mouthpiece I own, trying to find a "winning combination".
It seems to me that most well-designed tubas are pretty mouthpiece insensitive, whereas many are highly sensitive to changes in the bowl shape and depth. (I am speaking about intonation, rather than response issues.)
I have an idea that tubas that have the valve section placed in one of a few very advantageous "zones" along the taper are more stable, and that horns with valve machines located at the edge of one of these "zones" tend to be less stable in this regard. You can't just paste on a machine where the taper reaches the correct ID. There seems to be (again with that term) a "zone" or "zones" where you can safely have cylindrical tubing with little to no ill effects, A well-researched bugle will have these locations sniffed out, and the small-end wrap will be worked out so that the valves are squarely in the middle of one of these zones.
And most tubas have the valve machine within one of these zones, but some seem to have them right at the edge. If you move them an inch or two up or down suddenly the horn becomes "mouthpiece sensitive, when otherwise it would have been more stable. (I used to think that mouthpiece sensitivity was bunk, but all my messing with horns this past decade has made me think about this a lot more.)
So, with all this in mind, I suspect the original Kurath wrap (versus the later Willson wrap) was right at the edge of such a zone, and that he eventually dialed in the exact location (height?) of the valves and leadpipe through experimentation. And I may have uncovered this "trade secret" by doing all this work. The horn was about as dead to mouthpiece selection as you can get, but it was like a 2165 version of an F tuba: a little "hooty" and lacking in clarity.
The leadpipe I made (that properly met the 1st valve knuckle) had to be about an inch longer to end up in the same location at the receiver. This shifted the entire machine one inch farther down the taper once the MTS had been corrected to allow for the longer leadpipe. Add to that the fact that I installed one more valve and its "twisty" where it had earlier been straight tubing, and another shortening of the MTS to account for that added tubing, and now you have the end of the machine two full inches farther down the taper of the horn.
And now the tuba is extremely mouthpiece sensitive, more so than any other tuba I have played. I was worried that I had screwed something up, but I was wrong. I just had to find a mouthpiece type that it likes and then retune all the slides and "figure stuff out".
Now, with the fingerings that I had always used as alternates being used as the primary fingerings, and with the slides pulled appropriately, the LOW REGISTER response and intonation are far, far better than they have ever been. However, some things are now either not as good, or perhaps all this careful work has simply alerted me to stuff that I had been ignoring. (???)
My one issue seems to be 23 (sigh… it's always the 2-3 combo that is F'ed up) Db and Ab in the staff are very sharp. I can fix that, but then D and A played 3rd are then very flat, and as 12 they are very sharp. With six valves it is not easy to move the 1st slide (and no, using a trigger with my right thumb is 100% out of the question). I have to learn to work around these two notes. Also, low Gb is sharp as 23456, and 123456 is pretty much an F. Other than that, the horn is nicely evened out now.
I can play freely in the low register for the first time, ever. The low Bb had been very "low C-ish" as though a valve was halfway down. Now it has a more edgy tone but it is in tune and blows freely, so that alone is a boon to me. And now with the 6th valve replacing the 2nd the whole low range is very well in tune, which, of course, means that with the notes well centered it responds down there better, too.
Yesterday I spent two hours in the Snedecor book, and when I worked on the Malcolm Arnold "Quintet" everything was better in pitch and response and the new fingerings, while different, were much easier once I got used to them. I have become pretty adept at reading with six valves already. The transition was — for me — essentially effortless. Once I was past the initial slide setup and writing out of a fingering chart I never had to look back. I have definite, set fingerings for everything below the staff, with the pitch being stable enough that they work well in all 12 key centers. This is a great thing. The middle of the staff hovering around the sharp, open C is more of an issue. I have to play that C 13, but it is close enough that I can play it open in F or C major or A minor, but not in any other keys. The C# and G# are still problematic, but again, I will figure them out at some point.
I am amazed by how dead-on the sound and intonation of the Chaconne from the Arnold is now. And the "low-note-y" third movement is a lot easier and better, too.
I have decided to order a pair of custom-ported rotors from Miraphone that place the stems in better locations (to allow simpler/better linkage systems to be installed). I plan to build a new 56h/6th section that is detachable from the pistons because I have liked having that feature on my Holton. (It has been VERY handy.) Once that is done I can finally finish up this project by cleaning every joint to a high state and then lacquering the slides, buttons, caps, leadpipe, and bugle. I probably will NOT lacquer the piston section as I hate to have to burn up lacquer when I want to move something or take something apart. And the cheap lacquer I will be using will burn black when the flame hits it. If I ever set up to do epoxy lacquer and build a heating booth I might tackle the spaghetti of the machine, but until then — no way.)
I will be back with this thread once the final 5th/6th section has been built and the new linkages have been sorted. This will probably be in August.
Oh, and the winning mouthpiece?
Doug Elliott (1995)
R cup
R5E shank
4N 132 rim
I need to get either a Euro receiver or an R5 shank. But other than the thing only fitting in about 5/8" to 3/4" it does not wobble and it plays great. I just want to try a properly fitting shank to see what that does. (So as my ad says:
WTB/WTT Doug Elliott old-style R5 Shank)