The Amperex PQ White Labels I have been using are very nice and may indeed be best for some systems, they seem to provide a very splashy, dynamic, exciting sound with a good amount of detail, no harshness and a quite natural sound. That said, last night my first listen to the Siemens early sixties cca's was something really special. There is a loveliness, control, evenness across spectrum, and a wonderful revelation of deep inner detail such as easily hearing the quailty of wood within a viola, violin, and cello sound. I became so enraptured with each genre I was sampling that I did not get to jazz, rock music, organ, and a few others but surely enjoyed classical piano, Jennifer Warne, Johnny Cash, and Scottish Fantasy classical string.