After some 7 months with my new Yamaha YFL674, I still have difficulties with a few notes:

Eb (2nd octave. Sounds weak and airy no matter how I try to adjust embouchure, speed and direction of air.

D (and D#, of course), same problems than Eb, though less noticeable

F sharp (3rd octave). This one sounds OK (well, a little sharp, but I can adjust with some effort), but it often falls to a lower note. I must be extremely careful not to fail that note.

I do not recall having those problems with my older Gemeinhardt.

Have you, Yamaha-with-EC-cut owners, experienced similar problems? If so, how did you solved them?

I know I could sound a little obsessed, but, could they have any relation with the cork position?

I will appreciate any help, as I am starting to feel a little bit frustrated...

I doubt the cork position has anything do with it, but you could have it checked just to be sure. That's extremely simple to take a look at, and ccorrect if necessary. I had the same problem with F#'s with the EC when I first started using it, but with a bit more pressure, I learned to control them, and it really isn't a problem anymore. I never did have problems with the Eb's or D's, though. In fact, those are some of the nicest sounding notes on my flute, and I believe mine is the same model as yours. Try focusing your airstream downwards and uncovering the embouchure hole a bit (I had to uncover the EC more than most heads I've played to get the best possible sound).

Thank you all.

Yes, I do finger Eb and D the correct way. Should I not, the sound becomes worst still.

The quality of those two notes (Eb and D)is surprisingly different to the rest of notes around them, something that makes the problem more noticeable. And this is exactly the contrary to Flutist06 experience.

Tomorrow I will try focusing the airstream downward and uncovering the hole further. I have already tried everything, but will concentrate on that.

As for the F#, I believe I will be able to manage it more sooner than later, only that it is quite difficult compared to most other notes and I was curious to know others experiences. The technical explanations from Micron are very useful, thank you.

I believe the cork is not in the position it should be, but it came so from the distributor (Flute World). If measured with the rod, the rod mark appears almost on the right border of the blowing hole (the farthest side from crown) and not in the center of the hole.

But it is a new flute I am reluctant to try moving it myself, particularly if the problems I describe probably are not related to the cork position, as you say.

Most of those marks on cleaning rods aren't terribly accurate, anyway. Jon Landell has his own tool with markings on it to figure out where the head should be, because he doesn't trust the cleaning rods.

It could possilby be that the flute has a leak somewhere. It could have gotten knocked around in shipping. I would have your teacher try it out and see if he/she has the same problem first, then you can at least rule that out. Does the EC head fit on your Gemeinhardt? If so, you could check it on that flute and see if it is that particualar head that is giving your problems. Or try the Gemeinhardt head on the Yamaha.

Kara, They do not fit OK, but I cannot recall now whether it is the YFL headjoint that fits too lose on the GMH or the other way round. Having my teacher try it is complicated, she seems not to like playing her students flutes (for hygienic reasons, maybe). She did it once (because of my problems with the C 4th octave) and I do not dare to ask this again.
In fact, her comment is that the Eb is acceptable, it is rather me that I am not satisfied.
But I believe the problem is real, only that teacher tries not to show me the weak sides of my playing (I must have several) all together...
OK, I leave this for tomorrow, it's 2AM here now.