Posted by Klaus on September 17, 2001 at 17:48:48:
In Reply to: Thayers on tubas.... posted by Austin H. on September 17, 2001 at 16:09:30:
As I am not too fond of rotary valves on low conical brasses I have done some thinking on this topic like you have.
I am not too fond of the large bearing surface and of the maintenance aspects of the Thayer system.
As I find that well designed pistons give the least interruption of the airpath, my suggestion would be a 5th valve with a moving part in the shape of a piston, but mechanichally acting as a rotor mouted between tapered bearings in the valve caps.
The idea is not mine. It has been applied on one or two horn models by Kalison.
Klaus