Hi Look up the Kube-1 and Kube-2 on the Kef website and the specs for both show Amplifier requirements: 200W built-in Class-D There is nothing at all about a Kube-1.5 which is mentioned in the What HiFi? review of the KHT2005 HD1 speaker package here , a package I'm considering buying secondhand. Doing some Googling I'm pretty happy that a Kube-2 is indeed 200W but for the Kube-1 some results say 200W and some say 150W. Do both exist and could that be true of the 1.5? Also, is there a direct correlation between what is printed (underneath power socket) next to the input voltage/frequency for power and the built in Class-D amp? Not always easy to see but images online for the Kube-1 can have 150W or 200W. I've been sent a picture of the Kube-1.5 in question, believed to be 150W but it shows 100-240V - 50/60hz 200W Thanks for any thoughts.