Having heard them both in my living room, I'd say the Cal Audio Ikon II by a wide margin. The Rega, which I borrowed from a friend, was extremely bland compared to the Ikon, by itself and also driving a Cal Audio Sigma DAC. The Rega (I love their turntables, btw) seemed to be playing the bits and bytes, but not the "music." Not so with the Ikon, which has soul. The tube DAC added a bit more warmth, but was not an essential addition.