(1) Tested Sylvania 6N7 Tube Date Code 3-26 Medium Mu Twin Power Triode Tube

(1) Tested Balanced RCA 6N7 Tube Date Code 922 Medium Mu Twin Power Triode Tube

(1) Tested Delco 6N7 Tube Date Code 213 Medium Mu Twin Power Triode Tube

(1) Tested Philco 6AT6 Tube Date Code 50-26 Twin Diode High Mu Triode Tube

(1) Tested Sylvania 2AF4B Tube Date Code XY Medium Mu Triode Tube

(1) Tested Philco 8FQ7 Tube Date Code N-41 Japan Medium Mu Twin Triode Tube

(1) Tested Sylvania 12AV6 Tube Date Code bh AUN 12AV6 Twin Diode High Mu Triode

(1) Tested Sylvania 6SR7 Tube Sylvania 6SR7 Twin Diode Medium Mu Triode Tube