Low power tube amp for Sonus Faber?

I have set up a pair of 40 watt single ended tube amplifiers to a pair of the Sonus Faber speakers. The customer was thrilled. I think you will love it.

I use a 45 watt/ch tube amp with my SFGH’s...a superb match. However, the answer to your question involves many variables. The size of your room, the particular tube amp you are going to go with...and it’s ability to drive lower impedance loads, the quality of the particular tube amps transformers, the type of music you play, the loudness that you like...and on and on. IME, Elipsa’s will typically respond well to an amp upstream with some good power...so 30watts/ch might not do it for you, but again...many unknowns and variables.Best answer is to borrow/demo the amp you are considering and see for yourself.

specs on your speakers 91db SPL (2.83 V/1m) 4 ohm load
i am using the mastersound compact 845 on a pair of rosso fiorentino volterra speakers
with specs 87db spl (25.83v/1m)  6 ohm  3 ohm min.
my room is 12"x15"x8"  i get plenty of volume.
the mastersounds have great transformers.

ei001h
Low power tube amp for Sonus Faber?
Mastersound 845 compact for my SF Elipsa SE.
It uses 2 845 Valves, single ended at 30W per Channel

https://www.stereophile.com/images/archivesart/1207SFEfig01.jpg
" the speaker is still a demanding load for the partnering amplifier, with an impedance magnitude that drops to 2.5 ohms throughout the upper bass (fig.1). There is also a punishing combination of 4 ohms magnitude and –50 ° electrical phase angle at 70Hz that will suck gobs of current from the amplifier".


No No and No, from 70hz through to 180hz the bass power region you need an amp with current, at 70hz especially it could be lower than 2ohms EPDR as seen by the amp.

They will work and sound ok, but the bass will be nothing like it could be.

Cheers George

maybe look at the mastersound evolution 845 amp.