Tuning a bass trombone (trombones with valves)?

[Burgerbob]

It's probably not sharper, but the bell position is different.

[cmccain]

But ... what appears to be the case on my new bass is, that the f and c I used to play with the f-trigger, both speak better with the g-flat trigger and ... b and e also sound/speak better with the g-flat trigger! E and B however also speak better on my new horn with the f-trigger than on the old Yamaha, so I use either f or g-flat trigger contextually. Means relearning some stuff, but when I have, it sounds and feels better.

I have the same experience with my horn (Bach 50B). My default for any of those four notes is open or Gb tuning, though I do still use F for those notes contextually. I tune my F valve the "tenor way" with C in first (a little off the bumpers) and an unusable F, then tune D to be in first similar to open Bb, which puts Gb in a flat first. To compensate, I've had to get comfortable with Eb and D in the outer Gb positions to avoid rapid valve switching (which I can do if there's no better alternative).