I have extensive experience with the Cabasse Farella 401's with a Pass Labs Aleph 3, a SE DHT amp and P-P tube amps and while all 3 offer very good matches, the SE DHT amps and the 401's are an all around very good combo both musically and performance wise. However, the 401's are a little light in the lower registers but at the same time pitch resolution is very good and this leads to the "bright" description many find when the 401's are poorly matched and this includes system cabling. When carelessly paired with mediocre SS amps and budget cabling, the 401's are ruthlessly revealing and thus the speaker is blamed.
I did find that removing the passive crossover from the 401's and mounting them externally improved the resolution of the 401's quite a bit and is well worth the effort and for full range performance, a musical/pitch articulated subwoofer is necessary as when paired with such a sub, the overall result is a music system that allows one to be drawn into the music and forget about the mechanical/electrical means by which the music is being reproduced.
I did find that removing the passive crossover from the 401's and mounting them externally improved the resolution of the 401's quite a bit and is well worth the effort and for full range performance, a musical/pitch articulated subwoofer is necessary as when paired with such a sub, the overall result is a music system that allows one to be drawn into the music and forget about the mechanical/electrical means by which the music is being reproduced.