User Feedback for Sophia Electric™ 300B Mesh Plate Tubes - By Blair Hansen (2004)
It's been more than 18 months since I purchased Sophia Electric 300Bs (brown base premiums) for my Cary 300B Signature monologs. At the time you expressed hesitation about the appropriateness of the Sophia Electric 300B for that application, I think your concern was that the Cary operating point is too high for the Sophia Electric's.
After using (abusing) them almost daily, for well more than a year, but less then two, I would say they work pretty well in my application. By "abusing" them, I mean that my family and I are less then consistent about turning the amps on and off, using the standby mode or just starting from cold. Teenagers have been known to party in my listening room! Still, the tubes function as they did when they were first installed.
It's only a data base of one, but I think it's OK to recommend these tubes for use in Cary Monoblocks. And aside from the lifecycle issue, I think that these sound quite good as well (I compare them to new stock WEs).
I hope my experience is of interest to you.