We have been experimenting with tube amplification for CR1s, and I have to say, they can definitely sound amazing in a bi-amped configuration. We used a pair of BAT tube amps on the mid/high drivers and a Ciamara custom solid state amplifier (Class A/B, 350W at 8Ohm, Damping Factor >400) on the bass drivers. The combination was stunning. If you want to listen to all kinds of music, and not just the well-recorded stuff, tubes are a really nice addition. They mellow out some of the harsher recordings without sacrificing resolution. Obviously this is not easy to set up, as you need to gain level the amplification. The Ciamara amplifier has on-board trim for this purpose (we mainly use these in larger active sound systems). I highly recommend giving this a shot ... Next experiment will be to play around with tube amps from Audio Research and Thrax ...