Assuming this is true...,

[Bob Kolada]

Cause that's the way they've been made?

[imperialbari]

The directions of rotor movements shall not be changed.





That would skew the original, carefully calculated, resistance and impedance coefficients.

K

[tubaforce]

If you yelled for 8 years, 7 months and 6 days you would have produced enough sound energy to heat one cup of coffee.

...is it REALLY important, then, which direction rotary valves turn?

If it IS really important, why do $15K handmade triple horns STILL have one that rotates the opposite direction?

+1!
But "...some people, you just can't reach..."
Strother Martin, in "Cool Hand Luke"

Al

[SousaSaver]

I guess you would have to ask Meinl-Schmidt...

[sousaphone68]

Is just me or those that horn look like it is lying in state in it's silk lined casket

[tubaforce]

I would venture to say that if German brass instrument (and valve) makers are anything like my German colleagues in the organ business, then they are a curious and experimental bunch.
If there were anything to the valves turning the same way then at least one of the German makers would have done something by now.

Related question: How do the valves turn on high quality rotary valve trumpets? (three & four valve)

I've never really looked at an rotary Trumpet or Cornet that carefully! But the "direction" issue comes down to the player's perception. I know very fine players on both sides of this debate. If a player is willing to pay and possibly risk voiding any warranties, then so be it! There's no scientific basis, IMHO, for this practice. It's just like the Silver vs. Lacquer debate, merely a matter of perception And if that perception "helps" produce a desired result, for whatever reason, then I'm happy to just shake my head slightly and move on.
Al