Audio Research for Sonus Faber Extrema

Avico, you might try a used CAT preamp. Matching this to a ss amp like a Rowland or maybe a Plinius would yield I suspect a great sound with Extrema's.

Audio Research tries to get ss and tubes to be neutral. If that the sound you like then go for it. There goal is to try to combine them (sonically). Are they doing a good job at it? The best in the industry. Is it the rite sound? That for you to decide.

Avico, are you using 1 Meridian 557 amp or 2 557 amps.
If your using 1 557 amp, I say Forget getting a new preamp. Get another 557 amp and bridge them to 800 watts.
My friend is using 2 Meridian 557 amps bridged on the Sonus Faber Extrema.
We've ab/ed using 1 557 amp compared to using 2 of them on the Extremas.
When you use 2 and bridge them everything opened up.
The Extremas had so much more authority and naturalness in the midrange.
The Extremas need lots of power.
Now if you bridge them make sure you have the same version for the 557 amp.
I know their was a version 1 and version 2 for the 557 amp.
My friends system is as good as any system i'v heard.
The Extremas are incredible sounding.
The 557 amps bridged and tremendous sounding amps.