At the beginning of the Carmen Prelude, I extend the small slide at the end of my third valve slide, and use the appropriate alternate fingering for the 2-3 and 1-3 valve combinations, so that the Low F is available (1-2-3). There are intonation challenges with this approach, and while I can work these out without too much difficulty, my fear is that the slide will drop out during the audition. In fact this has happened to my instructor on a CSO audition, and he has heard it happen to many candidates as an audition committee member.
It's been a long time since I last worked up this excerpt, and my instructor has made some equipment modifications to solve this problem in his own auditions since then. I'm interested in doing the same.
I use a Bach Strad Bb Model 37, and the mechanism that keeps the 3rd valve slide from falling out has a post with a threaded stud mounted to the tube attached to the valve casing (facing the bell). There is another post attached to the slide with a through-hole that allows the threaded stud to pass through that has a double nut on the end.
My instructor had this reversed on his instrument so that the post with the threaded stud is on the slide with the stud pointing towards the valve casing. The through hole post is now on the tube attached to the valve casing. The threaded stud on his horn is at least half an inch longer that the standard stud
. This allows for the Low F to be played by throwing the third valve slide out all the way while extending the first valve slide and playing it 1-2-3 (no need for the extra slide to be pulled).
However, with this modified configuration, you only have to extend the slides for this one bar phrase, and don't have to fool around with lots of alternate fingerings and intonation issues leading up to that note. It seems like a very elegant solution to a frustrating problem. He uses it to his advantage for the Low F in Ein Heldenleben as well.