On another note...
I have a U47 with Andreas Grosser's solid state VF14 direct plug in replacement.
I like it.
Does that make me evil? No.
Does it make me an ignoramus? No.
I also own one with the VF14...
Both mics do not sound the same, but the A.G. does deliver the correct performance to be close enough to my ears.
Something to consider, I guess : one day there will not be almost any correctly functioning VF14 tubes.