Old vs new. 5th valve B&S

[bububassboner]

Hello all,
I'm having alexander do a good amount of work on my B&S symphonie f tuba. One thing that needs a change is the fifth valve. As some of you know, on the older horns the fifth valve wasn't quite a flat whole step. That makes the low register tuning a little bit challenging. On the newer PT f tubas this isn't a problem. So my question is this, does anyone here know the difference in length from the old and new slides? How much piping do I need to add to make it comfortable to play?

Thanks in advance

On a side note, for those of you who have owned a symphonie what have you had done to yours?

[Mark]

I also (as my 6-valve linkage is 2 + 4) put a right thumb trigger on the 5th valve slide ...

Why did you put the trigger on the fifth-valve slide and not the main tuning slide?

[pjv]

Larry Minnick lengthened my Symphonie's 5th to a flat 2 step and put a trigger on the 5th. Till this day I've only used the trigger whenever I want to play a pedal F with all 5 valves (instead of open). Ya, I can't figure it out either, but the entire scale from B down to Gb checks out every time without any correction with the trigger.

Almost a pity, 'cause its a nice piece of Minnick's work.

Who know's, maybe the 2 step is something for you.

Good luck

[bububassboner]

I lengthened my 5th slide, obviously, and used salvaged tubing from a bit-the-dust Miraphone 1270 (student model), which was the same bore and the B&S Symphonie F tuba's 5th valve tubing.

I also (as my 6-valve linkage is 2 + 4) put a right thumb trigger on the 5th valve slide (which required three or four attempts until absolutely perfect slide alignment was achieved, as I'm not one to sand/buff slides down in order for them to move effortlessly). The air suction had to be overcome for that slide to move fast, which required stacking 3 vent holes on the 5th rotor casing.

I've done little else, other than replacing the original (c. 1981/'82 era) links with what my experience tells me are the absolute quietest and most long-lasting links (so far, 25 years of silent and trouble-free operation), DuBro.

The stop system could be defeated and the slide could be pushed in farther, but the set range on my thumb trigger is (in to the stop point) in-tune for 5-4 B♭ - to (out to the stop point) in-tune for 5-6-1-2-3-4 low F.

pic for bubu.JPG

This was perfect. Did you find that you really needed three holes to get enough air out? Could you have gone with a long narrow slot to do the same thing or would there be problems with that that I'm not seeing?

What I was planning on having done was,
Lengthen fifth valve slide
Shorten third valve slide (my 23Db are all flat with the slide all the way in)
Kicker on the main slide under the right hand thumb
Vent all the valves

I thought about the fifth valve kicker but on this horn low f on down wants to ride high. Plus this horn has (save for the Db that will be fixed) zero flat notes. Everything is either straight up in tune or sharp. So the main kicker should be pretty sweet.

I was thinking about getting rid of the clockwork springs and 70s linkage but that might need to wait a few more pay days.

[bububassboner]

My horn is a five valve version. That's why I'm looking for a main tuning slide kicker. The low end can ride pretty high and it's pretty hard to bend the pitch down on these.

I dropped off the horn at Alexander today. Even got a private tour of their factory floor. I'm pretty excited to have the work done. Maybe down the road I can get a six valve assembly and install it.