how to make a Jupiter 470 euphonium play just about as well as a Yamaha 321 euphonium

[bloke]

(assuming clean, free of dents "which affect the sound", and in good mechanical condition)...

- Locate a model 468 Jupiter euphonium detachable mouthpipe assembly, in good condition.

- Remove the o.e.m. model 470 detachable mouthpipe from the model 470 Jupiter euphonium, and throw it in the trash.

- Partially install the model 468 mouthpipe into the model 470 euphonium by inserting the slide end and lining up the detachable receiver brace as closely as can be managed.

- Heat the ferrule on the insertion end just enough to make the ferrule's solder molten, and carefully tilt the 468 mouthpipe down until the receiver brace lines up with the other half of the brace mounted on the instrument.

- Insert and tighten the screw on the receiver brace.

- Play, smile, and think "13".