Boulder 865, Vitus SS-010 or Karan KA I 180& 8207;?

I can'nt comment on the others, but I tried the Karan K180 for over a year and could'nt get on with it. I found it quite dry, lacking tonality and a bit lacking in dynamics. It may just have been my system.
The Integrated I have just bought after some searching, may fit your needs, the Pathos Inpol. Only 50 watts, but Class A, very musical, dynamic, a lovely amp. Others I heard in my search that I liked, Ayon and Emille.

have not heard their integrateds but did hear the vitus monoblocks..sm-010 and they were superb..

never heard these amps with your speakers but I had the opportunity to listen to them in various combinations. Boulder is the one that I would pay attention ...

Used to have the Boulder amp driving my Memento and found the sound to be dry. You can look into Ayre or Krell which I think will match well with the Memento.

I tried the Boulder and the Vitus and the clear winner was...
... the Dartzeel CTH-8550!

In short: The Dartzeel give me the most natural sound, the Boulder could´t involved me really and bring me closer to the music. The Vitus had not enough power for my room and speakers (Ayon Eagle). Of course the Vitus is not bad but you will always have the feeling that more power would be better.

I don´t listen to the Karan but I read two weekls ago in an English forum that a user sell the Karan and go for the Dartzeel and is very happy.

Tom

The above post regarding the darTZeel sounds correct, as does the comment about the Boulder sounding dry. The darTZeel is the solution if you can afford it.

I finally went for the Esoteric C-03 + A-03 combo. Neutral, transparent and always in control with a touch of Class A-warmth. A great combination with the Sonus Fabers IMHO.