One thing to note is that Sophia tubes, while they sound good, are not reliable at all. 2 of my friends had pairs of the royal princesses and the one guy has blown 3 so far and the other has blown 1. I had a pair of mesh plates and blew one. I also had a pair of 845s and blew one.
I also have the 20k retail 845 monoblocks and went thru about 5 power transformers. At that point I switched to the Hammond equivalent and have had no problems since. I do love the sound of the amps but was less than impressed with this and their reactions when it was happening. They took zero responsibility and tried to blame the problem on everything and anything else. The Sophia power transformer was worth 400usd plus shipping and duties. It was comprised of the high voltage plate winding plus a low voltage filament winding. I separated the 2 when I bought the hammonds so I had to buy 4 transformers. All 4 ended up being about 250$ Canadian for what has obviously turned out to be a much better quality alternative.
At this point I wouldn't touch sophia tubes and would only buy their amps with the idea that I would have to do some mods.