Posted by Jay Bertolet on June 23, 1999 at 23:15:18:
In Reply to: suggestions on rotary valves posted by Bill on June 23, 1999 at 19:41:51:
It is true, as previously posted, that changing the springs might work. There are two other things that you could try.
First, take apart the paddle-bar assembly so you can clean the rod that runs through the paddle-arms. This rod gets caked with dirt and oil over time. Since it is the "axis" around which the paddles swing when you push the valve down, it needs to be as frictionless as possible to allow quick motion. If you aren't comfortable doing the disassembly/assembly of your linkage then have a professional do it. You don't want to mess around with these parts if you're not clear about what you're doing.
Secondly, you might try tightening the springs on your valves. I have mine wound VERY tight and they are heavier/stronger springs than normal. The big advantage of getting used to tighter springs is that nobody will ever want to thumb wrestle you again! :)
Honestly, I haven't played any piston valve tuba that had faster valves than my rotaries. Not to disagree with your teacher but I love my rotaries for their ease of use and their minimal amount of necessary maintainance, as well as there speed and feel. I'm of the opinion that properly maintained, rotary valves are every bit as functional as pistons and less work to keep that way.