(1) Tested Balanced GE 6GU7 Tube General Electric 6GU7 Twin Triode Tube

(1) Tested GE 7AU7 Tube Date Code 57-39 General Electric Twin Triode Tube

(1) Tested Sylvania 6GU7 Tube Date Code ad AFJ Sylvania 6GU7 Twin Triode Tube

(1) Tested GE 6ES5 Tube with Box Date Code JE General Electric Triode Tube

(1) Tested GE 6AS11 Tube Date Code JZ General Electric 6AS11 Dual Triode Tube

(1) Tested GE 6J6 Tube Date Code 56-22 General Electric Medium Mu Twin Triode

(1) Tested Balanced GE 6GU7 Tube Date Code RE General Electric 6GU7 Twin Triode

(1) Tested GE 6CN7 Tube Red Letter Date Code 61-26 General Electric Diode Triode