It also depends on the circuit, but I have also found the Siemens E88CC, Cca, late 50's, early 60's to be the most synergistic and musical sounding in my preamp. If you go with Siemens, try to find one date coded with A0 to A3. I have an A3 that is very magical. Even the Siemens of the same early 60's manufacture sound differently. Good luck.
