Hello all, been browsing for years and finally decided to join. I’m currently servicing a Yamaha 280 alto . It’s in good cosmetic condition and I’ve fixed any leaks I can find. There is still a really bad growl on low C,B,Bb notes. Very weird, crook is a good fit. I’ve noticed that it’s made in China and the internal seam is very noticeable. Could this be the cause ? I’ve been repairing and playing sax for 25 years so this is a new one for me !