So, I've been meaning for a while to change the tube in this mic and I finally just got around to doing it. Not being the first owner there is no way for me to be able to judge if the thing was still performing like new, which I guess is a good question for Al... Would a tube of this kind go "bad" in a relatively new microphone with reasonable use and care? Anyway, not to get too sidetracked...
The tube I removed is the original sE badged ECC83A and replaced it with Al's suggestion of a Ruby 12AX7AC5 HG+. The original configuration was always satisfying as a colour microphone, specifically for voice, but definitely suffered from a fairly substantial noise floor. I was curious, being not super familiar with the ins and outs of tube qualities in a setting of this kind, what I might find simply trying a replacement.
I haven't had a chance to do much with this new tube installed, but immediately noticeable is the substantially lower noise floor, which is something I was hoping for from a bare minimum standpoint. With a little bit of voice work, the extreme top end seems to be more open, with a dip in the upper mids seeming more pronounced with this new tube. More time with different voices will definitely help me asses if the overall sound is more complementary to what i am looking for, but just being that much quieter, with nothing else as a drawback, is enough for this to be a winning combination.
I will keep you all posted as to what I find as I go along with this.