(!!!!!) (Best E84L Matched Quad) E84L=7189 Siemens NOS 1977 rebranded for Radiotechnique France (RTC) 1982 (41.5ma, 42.5ma, 44.0ma, 44.2ma) (closely matched)
(!!!!) (Best Overall PAIR) E84L Siemens NOS 1978 rebranded for Radiotechnique France (RTC) 1982 (37.5ma and 40ma)
(!!!!) (Best Pair) 7189 Sylvania black plates NOS 1970 era (42ma and 46ma)
(!!!!) (Best Value PAIR) E84L Siemens NOS 1978 rebranded for Radiotechnique France (RTC) 1982 (35.8ma and 37.5ma)
(!!) (Best RCA Single) 7189 RCA NOS 1960's (45ma)
7189 Amperex Heerlen Holland NOS 1970 (44ma)
7189 Amperex Japan NOS misbranded 7189A NOS 1970 (48.5ma)
7189 Sylvania black plate NOS (80ma) (recommended for FIXED-BIAS amp only due to high current)
7189 Sylvania gray plate NOS (44ma)