Posted by Jay Bertolet on November 22, 2000 at 10:53:26:
In Reply to: Re: Re: Re: Favorite 6/4 CC posted by Bryan on November 22, 2000 at 01:43:01:
I think it is a good point you make about the complete reversibility of the process. This was exactly the approach I took adding a 5th valve to my tuba (thus the extra leadpipe I am offering with my Cervany). In the event that the modification didn't work out, I had the capability to return to the original configuration. No sense ruining a $4000.00+ instrument just to add a $250.00 part.
I personally have never played a dependent valve setup that I liked. Mostly this is because they tend to be fairly stuffy because of all the extra bends involved when both valves are engaged. I believe this type of setup on bass trombones was the genesis of the Thayer valve development but I can't prove it. I just remember so many players complaining about how stuffy the double configuration was. I also remember that the earlier in line double valve setups had lots of mechanical problems because of the logistics of the slide placement and the overall length of the two independent valves.
But most certainly, my opinion is that a dependent setup is much preferable on a piston valve BAT when the only other option is to cut the 5th into the leadpipe. I have heard of cases where this procedure worked okay but I would be very hesitant to try it out on one of my own instruments because of the problems that could occur disturbing the leadpipe. A dependent 5th might be the only relatively safe alternative I would risk.
My opinion for what it's worth...