Even though these sousaphones are bizarre (along with being held together with screws instead of solder), they're actually pretty good.
It's just that they have the same issue as all the other Yamaha marching brass:
When they come in for summer repairs, all of the valves have to be repaired - even though they're not actually broken. (Anyone who has ever worked on any Yamaha marching brass knows exactly what I'm talking about.)
To make them easier to polish, the valve sections come off with those same tiny little screws that are found on the top action Yamaha tubas and the rotary Yamaha tubas. Additionally, the large body branches are screwed together at two junctures, which is even more bizarre.
One of them that I had to repair today had an obstruction way up around the shoulder area which was obviously some soft material like rubber or plastic, because dent balls (towards the obstruction) would not knock it out towards the large direction. Since the valve section came off, I reluctantly removed those six screws, wiggled It off, and ran one of those Roto-Rooter type of tools (that some of us own... yes, for actual plumbing) down through the fourth and third branches (nice sturdy braided cable on that tool) and knocked out the obstruction. It was one of those little water bottles all wadded up - and with the lid on it. One thing I know not to do is to undo all those crazy screws that hold the large branches together in two places. It just seems to me that if one of these instruments was smashed up so badly that I'd be tempted to unbolt those branches, once the dents were removed and the branches were slightly distorted, I'd never get all those screws back in.
see...??
Typing up a bunch of crap about mundane school repairs is boring. Y'all just want to see us add seven additional valves to some York something or other... Oh yeah: and pictures. Y'all want to see pictures.




