Adapters for which particular tube(s)?
I agree, sometimes glue can come off inside the base or a piece of glass can brake off during production.
In case of broken glass it's best to shake the tube to make sure the lose glass goes to the bottom and doesn't touch the elements.
However it's very important to test the tubes before you use them in your amp to make sure there are no shorts or leakages.
The 6CG7/6FQ7 is the 9pin version of the 6SN7.
All you need is a 6CG7 to 6SN7 adapter.
I would not rule out tubes based on such broad generalizations. I love Sylvania tubes with my DT880s, they do not add to the treble presence bump at all but rather bring up the range below it just a hint giving vocals fantastic clarity.
The one with the clear glass and round plate? How is the sound? any similarity to the TS round plate?
It's one of Craig's favourites driver.
George I recommend the Raytheon 6F8G round plates too.
There are more than one type of TS round plates in the 6F8G bottle, I have posted photos earlier on.