Low power tube amp for Sonus Faber?

maybe look at the mastersound evolution 845 amp.

 The Sonus Faber Elipsa can sound beguiling with a tube amp. I own a pair of the Elipsa SE and drive them with an Audio Research Ref 110. They need high quality power to sound their best. A 100 wpc tube amp is about the lowest I would go. Without enough power, the bass will not be as crisp and well defined. Also it may impact the soundstage and they may sound a little closed in. The only way to know for sure is to hear the amp in your system. With the right amp and preamp these speakers sound amazing. Good luck!

My options are 845 compact or mc275. 845 evolution is not an option for me. 

I think MS is more high end than mc 275 (is this accurate ?) and I’m trying to stay away from Mcintosh. I’m currently using mc452 and c2600. 

@mboldda1 

how is your low end bass performance? 

@georgehifi 

I’m  not sure how to interpret those numbers. Also have an option to get an older Krell ksa300s, not sure if it’s superior to my Mc452. What do you think ? My plan is to have one SS and one tube for Elipsa. 

@ei001h  Also consider Lyric Audio.

Here is their Ti140 Mk2 integrated...

https://www.thecableco.com/used-components/used-amp/ti140-mk-ii-integrated-amplifier-silver.html

You will have ample power with 70 watts per side when using the KT150s. It allows for negative feedback adjustment and wide tube type (and variant) options.

I found it's performance to be superlative in conjunction with a power conditioner.

A lot will depend on your room size and listening habits.
The speaker efficiency is about 88 or 89 db 1 watt/1 meter; on paper the speaker is rated with the sensitivity spec of 91 db. But because its nominally 4 ohms, this means that the voltage into the speaker will be more than one volt; hence the lower efficiency.
With tubes, the efficiency spec is a lot more useful!!

30 watts won't be a lot of power on this speaker. I would consider something with more power. The low impedance dip in the mid bass is not challenging to most tube amps (including OTLs) so I don't think you have any worries there. I would shoot for an amplifier with 100 watts or so- you could get by with a 60 watt amp, but if you play tunes like I do, you'll be running the amp out of gas.