Hi again everybody!
Oliver: BIG THANKS!! This post contained more info than I have found about the mic in several months of trying. Highly appreciated!!
I forwarded the link to the service guy I am planning to use, and it made sense to him, so hopefully the upgrade will happen in the not too distant future.
JJ: I am glad you have good experiences with the tube seller from earlier. It sort of makes me feel I´ve bought a good tube before I have even listened to it. I guess that it will mean that I will be even happier AFTER I have listened to it...
To everyone else: Thank you a lot for your input!
Best regards,
Lars K