Are Sonus Faber Cremonas "Tube Friendly"?

Absolutely! The CREMONA's go fantastically with tubes! Try McIntosh or Graff f.e.
Good luck!

It would be best to have an amp with 2 ohm taps on the transformer. Or at least a Push-Pull amp with enough feedback for a decently low output impedance. According to the published charts, the Cremonas have 2.3 ohm dips at the bass frequencies and also large phase swings at the same area. This is the frequency range where the most power delivery is required, and is most demanding on the amp. Having to dump large amounts of power into the speakers to satisfy this demand, while reducing the damping factor significantly(due to the low impedance dip at this frequency)is not an ideal situation. I'd recommend an amp with an output impedance of lower than 0.5 ohms for this application. This will provide you with a damping factor of at least 4 at these difficult points, and help to ensure stability of the amp and control of the drivers.

IMHO.

The Cary will be fine. No worries. I bet it will sound great. Good luck.

Chris

I used a Cary V12R with Cremonas for about nine months until last week when I traded them for the Stradivaris. The Cremonas are great speakers and the Cary is a superb match. Used a CAT Ultimate pre amp and sometimes the AES 3 pre.Cheers.

The only "Cremona friendly" tube gear I know is VTL and Manley's. They use low output impedance transformers (0.7 Ohm secondary winding)
Be noted, that the bass can still suffer.