I've never marched with a tuba on my shoulder, but I have practiced standing up with one, and a few fun facts about me: my first instrument was a jupiter trumpet, and both tubas I use for band were made by jupiter (JCB-382 at home, JCB-378 at school) I like them both, and I feel like you really get your money's worth out of their instruments.
Yea they’re great. My first Jupiter was CTB-40 trombone and it did pretty well for a beginner trombone. Their marching instruments are heavy af though.
Our school uses Mk1s and they are good instruments, but I bet the 5 pound weight difference does make a big impact Especially for the freshmen that choose to try Contra
Please keep working on the valves of all of your brass. If you don't move them/oil them every day, they freeze up to the point of needing a trip to the repair shop.
