krell Ksa-50s and SF electa amator I,

Good match.

Hi, Alberto. Incidentally, a friend is solliciting amplification opinion for his EA II. Is your thread a question, or a suggestion?
I listened to EA II driven by Krell 100, YBA Passion, and Symphonic Line RG7 -- but not your KSA 50s. Pre and source were YBA. Cabling was ART and bearlabs. To my ears, the YBA gave the most (musically) involving results -- it made the amators "come alive" if you will. The RG7 came a close 2nd. By comparison, the sound through that particular Krell lacked vitality -- it probably didn't synergise with the speakers, the pre, or all; I cannot say.

BTW, SF offer own-brand electronics too. You may want to check those out as well.

This would not be my first choice. I own the SF 1's and think any 100w+ Goldmund and the GamuT D200 are wonderful. The Aloia's w/inductive power do remarkably well also. There are also several tube amps that mate very well. I am partial to the 845 based amps with the 1's.