Newbie Can't Decide Which Tube Amp

Because of the low sensitivity of a sonus faber  and the low impedance i would recommend at least a one hundred to one hundred fifty watt tube amp with 4 ohm taps. You could try and find a good 6550 or kt88 amp from audio research, sonic frontiers, or rogue. You should be able to find an awesome used model in the 4k range of that power rating. The only upgrade you will need in the future will be good nos tubes and a good power cord but you can add those later. i am worried that a fifty watt amp will run out of steam even on the blues.

I'd go with the rogue sphinx and save some money. It's a very nice amp for only $1500. It's got everything you would ever need including headphone amp and phono. All analog, which to me, is important. Tubes combined with class D hybrid, and it looks great.

i have a triode corporation trv-35ser (35 w integrated with pre in, el34 tubes) driving acoustic zen adagio jrs (6 ohm, 88 db) in my second system, and it’s a very nice combo.  triode is a cool niche brand, and the price is within your budget.  they also offer the trv-88ser (45 w integrated, kt88s), also within your budget.

I run PrimaLuna amplification and a tube preamp with Sonus Faber speakers. Great synergy!

Carver 275-I have one and you won't look back at 2500.00