I have a Keilwerth SX90 Tenor and i usually use a link STM 7*, but I also have a Ponzol M2 S 110. I use a 2 1/2 Vandorenn ZZ on my link and I get good/consistent intonaton(i can get the notes thorughout the range "in-tune") throughout all registers of the horn, even into altissimo. The problem is with my Ponzol i cannot get a high D in to tune, and even if i can, the high Eb and above are extremely flat. I use a 2 1/2 ZZ on the ponzol as well, and I have tried vandoren ZZ 3.5s, rico Jazz selects 3M and even rico royal 2.5s. Does anyone have a similar problem, or suggestions on how to fix mine? Any help would be greatly appreciated.