Double tuba... What?????!!

[Mike-ICR]

I know it's a double tuba. I understand the concept. I'm really just interested in that beast of a rotor running horizontally through the valve slides. Do any of you know:

What it is?
Who makes (made) it? (I can see that Yamaha made the horn but the rotor must be after market)
How it actually works?
Where to get it?

[Dave Hayami]

Hi Mike,
Check the archives, Built for The Late Tommy Johnson by Robb Stewart(CA).
He built 2 of them for Tommy.
Dave Hayami

[NDSPTuba]

You see that kind of valve in the Horn world on a relatively common Bruno Idyl built compensating double horn. Which is what that tuba is. It is a compensating double tuba. One obvious disadvantage to this design as you might have already seen. You can't tune all the valve slides on one side ( short side, F ) of the tuba. And on this particular instrument you can't tune the 2 valve slide for either side of the tuba.

[Mike-ICR]

One obvious disadvantage to this design as you might have already seen. You can't tune all the valve slides on one side ( short side, F ) of the tuba. And on this particular instrument you can't tune the 2 valve slide for either side of the tuba.

I noticed that for the 2nd valve but part of my attraction to this instrument is that you CAN tune the short and long sides of the 1st, 3rd and 4th slides. I'm glad I'm not the one who has to clean out that 2nd valve crook.