Four mos. ago I purchased a Mark VI. After playing it for 2 mos, an interesting event took place. While in the middle of practicing a piece, I struck a note and no sound was produced. It was as though someone pulled the wall plug out. Several attempts at simply repeating the note (and others) were fruitless. It felt as though something was blocking air entering the moutpiece (no, I wasn't chewing gum at the same time). Eventually, sound resumed, but at a very diminished quality (airy sound and hard to blow). Brought the horn to the best tech in town (7 wks ago) who made some adjustments, seated a few pads, replaced a few, and away we went. The VI has been great 'til yesterday. Guess what. Same phenomena! Tried single and double embouchure; changed out reeds (3X) and even changed mouthpiece and reeds together to no improvement. I'm bringing the horn back to the tech today for re-eval. In the meantime, has anyone else had this experience and, if so, what was the outcome?