Posted by John Swensen on November 15, 1999 at 14:32:36:
In Reply to: Tuba modification posted by Jeremy Rosen on November 13, 1999 at 08:58:27:
In reverse order:
It would almost certainly be a better idea to just buy such a horn.
It would probably cost quite a bit more than buying a new rotary valve horn, unless you happened to have a complete rotary valve section (including all tubes) from a similarly-wrapped horn lying around. If the 3/4 BBb 4-piston-valve horn is very good, but has leaky valves, consider having them rebuilt.
It is possible to convert a piston horn into a rotary valve horn, but that would be making a new (different) horn out of the old horn. If you compare a PT-6 (rotary) to a PT-6P (piston), even though the two horns share the beginning of their model number, the bell, and the first couple of branches, they are different horns, with different sounds and feels. Both horns are outstanding, but different.