Which 12AX7 tubes for EAR 834P phono stage?

I am experimenting with vinyls, and acquired EAR phono stage for a starter. I've compared the sound of EAR against Camelot Lancelot, and Sutherland PhD on two different systems. To my ears EAR sounds lush and smooth, perhaps a little too much so. I would like more lively and dynamic sound, like Sutherland phono stage. Can I replace the tubes in EAR and make the sound to the direction of more lively and dynamic? Or do I need to look for a different phono stage? I'm currently using a Rega table with Benz Micro MC cartridge loaned from my friend. I will be using a B&O table with moving iron MMC 20CL cartridge when I have everything set up next week or so.