Tuba Buzzing?

Question:

Tuba Buzzing?

I have a question about my tuba: I have an old YB-621, it's not my own it's the schools, and I have been trying to use it to practice at home but whenever I play certain notes (usually not pressing any valves, often the D and F on the bass clef and sometimes the Bb on the top line) it buzzes at random intervals. When it does this it feels a little different on my mouth, but not substantially. It's a BBb tuba.

Best Answer - Chosen by Asker: Check your water keys (spit valves). One of them may be loose or cracked, allowing air to escape and causing the buzzing. A short-term fix is to put tape or a tissue over the cork. You will have to have a new cork put in to fix it for real. Good luck!