Posted by Jay Bertolet on August 04, 2000 at 21:51:30:
In Reply to: adding a dependent fifth valve posted by Bill B on August 04, 2000 at 18:41:32:
I would advise against this. Yamaha tried this same thing years ago with their YEB-321 Eb tuba. They mounted a 5th valve into the 4th valve tubing, with a left-hand actuated lever. I played a couple of these tubas and the 5th valve was a disaster. In my opinion, the valve didn't give all the benefits of a real 5th valve because the 4th had to be engaged for it to function. Also there were tight crooks coming out of the 5th valve into the tubing, just what you don't want. I felt the valve was overly stuffy and hurt the sound of the tuba. Unless the 4th valve tubing area you're working with on the 191 is bigger, you might run into the same problem. Is there enough straight tubing in the leadpipe just prior to the 1st valve to add a 5th valve on top of the current valve stack? Rudolf Meinl tubas use this design and I've added this type of valve to one of my CC tubas and it worked perfectly. By that, I mean it didn't affect the intonation or resistance of the horn at all and the valve played just like any of the other valves and just as well in tune. This type of valve would at least give you all the advantages of a true 5th valve. The only thing you lose is the removability of the 5th valve but since it doesn't affect the horn, that would just mean the added weight to the tuba. Just an idea.
My opinion for what its worth...