(!!!!) (Best Pair) 6CA4 RFT East Germany (Funkwerk) NOS 1970's (50-50/40 and 50-50/40)
(!!!!) (Best Single) EZ81 GE Mullard Blackburn UK "O" getter NOS 1966 (57/40 and 57/40)
(!!!!) (Best Single) EZ81 Mullard Blackburn UK NOS branded Motorola "D" getter 1960 (57/40 and 58/40)
(!!!!) (Best Single) EZ81=6CA4 Philips Australia NOS 1974 (58/40 and 58/40) (similar sound to EZ81 Holland) 1% section balance
(!!!!) (Best Value Quad) EZ81=6CA4 RFT East Germany (Funkwerk) NOS 1970's (1 quad)
(!!!!) (Recommended Pair) 6CA4 RFT East Germany (Funkwerk) NOS 1970's (47-48/40 and 48-48/40)
(!!!!) (Recommended Pair) 6CA4 RFT East Germany (Funkwerk) NOS 1970's (49-49/40 and 48-49/40)
(!!!!) (SINGLE) EZ81 Bogen Mullard Blackburn UK "D" getter like new 1963 (56/40 and 57/40)
(!!!) (BEST PAIR) 6CA4 RCA NOS 1969-1970's (52/40 and 53/40 x 2 tubes)
(!!!) (BEST RCA SINGLE) 6CA4 RCA NOS 1963 (53/40 and 54/40)
(!!!) (Best Single) EZ81=6CA4 RFT East Germany NOS 1970's (49/40 and 49/40)
(!!!) (Best Single) EZ81=6CA4 RFT East Germany NOS 1970's (49/40 and 50/40)
(!!!) (Best Single) EZ81=6CA4 RFT East Germany NOS 1970's (50/40 and 50/40)
(!!!) (BEST VALUE PAIR) EZ81 Radiotron NOS made in India 1963
(!!!) (Recommended Single) EZ81=6CA4 RFT East Germany NOS 1970's faded printing (50/40 and 50/40)
(!!!) 6CA4=EZ81 GE NOS 1960's -1970's (52/40 and 54/40)
(!!!) 6CA4=EZ81 GE NOS 1980 (55/40 and 55/40)
(!!) (BEST VALUE SINGLE) 6CA4 RCA branded Tungsol NOS 1960's slightly tilted glass and top mica (52/40 and 52/40)
(!) (BEST PAIR) 6CA4 RCA NOS 1960's - 1972 (54-56/40 and 54-54/40) (Wright, Counterpoint, Cary, Zanden)
6CA4 GE branded Tungsol like new 1960's (55/40 and 56/40)