I have Elipsa SE paired with SET 845 tubes. Documented 55W per channel.
My amp Mastersound Evolution 845 drives Elipsa to concert hall levels without breaking a sweat. Solo instruments e.g Piano and Cello sounds better than Live! You can’t beat realism of a SET tube amp on reproduction of musical instruments.
I was told 50W tube amp will be inadequate for my hungry Elipsa's with demanding curves down to 2ohms. Don't believe the numbers and what people tell you here. They give opinions based on theory. Do your own test and you will be surprised what works. I have a 25W SET that also sounds amazing with Elipsa. Quality of transformers is often understated.
I listen to classical almost exclusively. Send me your phone number Ill send some videos of my system.