Always heard more good clean power the better with them. High current, high watt, high damping factor is what I would be looking for. I’ve never heard a person recommend a tube amp with these speakers (if you listen loud at all) except AudioTroy above. Never know I guess.There are lots of stories of people with 250/300 watts saying it’s not optimal and I would tend to agree as they are really big and really not efficient compared to most big speaks.
When I heard them they were on monster monos although I cannot recall what it was (maybe a big Bryston) and they were really good although a little dry.