The Cal amp will drive the Confidence with ease. I'm using mine to drive a Mcintosh speakers set-up. Mcintosh LS360, CS350 center, WS350 surround. The LS360 is rated to handle 600 watts a channel. With two channel, the Cal amp clips at 750 watt. Also the power rating of 500 watts a channel is for distortion below 1%. If like most companies the amp had been rated at 1% the power rating would have been given as 700 watts a channel. For me the amp provides basically unlimited power. I can't sit in the room with it at full blast. With all of this power, the amp is still very detailed and delicate sounding. I believe that part is more surprising than the power.