(1) Tested Sylvania 6ES5 Tube Date Code AAU High Mu Triode Tube

(1) Tested Philco 6AT6 Tube Date Code 50-13 Dual Diode High Mu Triode Tube

(1) Tested RCA 6AN4 Tube Date Code KJ RCA High Mu Triode Tube

(1) Tested RCA 6EB8 Tube Date Code AP High Mu Triode Pentode Tube

(1) Tested Sylvania 6T8A Tube Date Code ab ESO Triple Diode High Mu Triode Tube

(1) Tested Westinghouse 6EB8 Tube Date Code 69-22 High Mu Triode Pentode Tube

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

(1) Tested Philco 6JE8 Tube Date Code EBF High Mu Triode Sharp Cutoff Pentode