(1) Tested RCA 6AU6 Tube RCA Sharp Cut Off Pentode Vintage Tube (a)

(1) Tested Admiral 6AU6 Tube Date Code 939 6AU6 Sharp Cut Off Pentode

(1) Tested RCA 6CB6 Tube Date Code 504 Sharp Cut Off Pentode RCA 6CB6 Tube

(1) Tested Sylvania 6AU6 Tube Sylvania Sharp Cut Off Pentode Tube

(1) Tested RCA 6AU6 Tube RCA Sharp Cut Off Pentode Vintage Tube (b)

(1) Tested RCA 6AU6 Tube RCA Sharp Cut Off Pentode Vintage Tube (c)

(1) Tested Philco 6AU6 Tube Date Code 247 Philco 6AU6 Sharp Cut Off Pentode

(1) Tested RCA 6CB6 Tube RCA Sharp Cut Off Pentode Tube (b)