Posted by John Swensen on October 06, 1999 at 12:30:15:
In Reply to: Re: Re: Pistons v. Rotary posted by Christopher on October 06, 1999 at 08:29:42:
Traditional rotary-valve tubas tend to have longer lead pipes than York-style piston-valve tubas, so rotary valves are, relatively, further down-stream than piston valves.
An interesting research paper on this subject is this paper on the microstructure of slurs.
I can say that, on a (rotary) PT-6, slurs are smoother and more fluid than on a (piston) PT-6P, where valve changes tend to "pop" out ever so slightly more. Slurs on the Holton and Nirschl York-models I tried also behaved the same, relative to the PT-6 (I could easily have a lasting relationship with any of these horns, although I am currently with a lovely PT-6P).