Well, i`ve got an old conn coprion bell trumpet and last month the cork inside the valves teared apart. I tried replacing it with an eraser and it had a good sound except on the low register. Then I tried with a cork and denim which was great but later I still got some trouble with low register. And sometimes I think its me but I donīt know what to do because I can`t find a replacement kit.
And I`m also wondering can the cork affect the low register sound? And where can I find a valve felt cork replacement?