So, sorry if this is a long story. I bought a new Besson 2052 from woodwind brasswind in March, and after about 3 weeks or so it started making this metallic vibrating sound on certain notes. I tried everything, and I mean EVERYTHING, to make it stop. I reset springs, took parts off the horn to see what was causing it, oiled everywhere metal touched metal, and took it to two repairmen, one of which is highly recommended by my studio teacher at school and repairs CSO brass instrumants. He had no idea how to fix it, so I eventually gave up and got a new horn from W&B (they have a 60 day return policy). Everything was working great until tonight, when, for some unknown reason, my new horn started doing the exact same thing. I'm definatly not covered by the return policy anymore and judging by the results I got when I tried to get the first one reparied, getting it fixed is probably not going to happen. What gives??!!!? Has anyone else had the same problem or ANY idea of how to fix it? I've tried everything obvious like tightening screws, oiling moving parts, and so on.