Cyrus, If you are choosing a tube like Sophia or Takatski, you would have an assurance that these tubes would be fine in your amp since they were designed with the same filament current draw of 1.2 amps and other operating points as the Western Electric 300b. If you choose Elrog, EAT or EML, I would suggest contacting both Audio Note and your chosen tube manufacturer to make sure that tube will function with no issues in the Kegon. Audio Note may have real world suggestions as to which highend tubes they like with this amp especially if you are using Audio Note speakers. Regards Jet.
