Posted by jo-blo on May 20, 2003 at 18:46:31:
In Reply to: DuBro revisited posted by jlb on May 20, 2003 at 11:14:25:
The cone-shaped riser and all the rest sit on top normally. With the very old "S"-arm receiving stop arms, there is an opportunity to do something kinda neat:
After tapping a 4-40 thread down through there (The original metric thread size is not far from 4-40 anyway.), you can slip a 4-40 nut into the slot that formerly received the S-arm. Once everything is screwed together, you can turn that nut down tight and it becomes a "lock" nut.
Not to be a repair-guy snob at all, but there are quite a few subtile installation operations that can enhance the performance of this system. It might be worth it to pay someone who is experienced in putting these on a tuba - though admittedly this is quite inconvenient for many.