Posted by Chuck(G) on January 04, 2003 at 23:31:14:
In Reply to: adjustable cup mouthpiece? posted by Frank on January 04, 2003 at 22:26:12:
I think one's still made by Gerry Endsley in Denver. I've got one made by him with a screw rim and shank. They're not cheap.
These things work by making the cup in two parts--the first part is attached to the shank and functions as a piston in the threaded second part that's attached to the rim, which functions as a cylinder. Very simple.
So, does it work? Yes, but not well. Here's the problem--the cup as it changes depth cannot change shape, so when it's set deep, the sides of the cup form a straight cylinder, not something that you'd normally want in a mouthpiece.
I've found that there are only one or two positions where an ACM works well at all. Chalk this one up as a curiosity. Maybe it works better on the high brass, but it's disappointing on a tuba.