(!!!!) (Best Single 1966) EZ81 Mullard Blackburn UK NOS branded Realistic Lifetime gold pins 1966 (56/40 and 57/40)
(!!!!) (Best Single) EZ81 Mullard Blackburn UK NOS 1959 (56/40 and 57/40)
(!!!!) (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 GE Pair) 6CA4 GE NOS slightly tilted glass 1% matched (55-56/40 x 2 tubes)
(!!!!) (Recommended Pair) 6CA4 GE NOS slightly tilted glass 1% matched (54-54/40 and 54-55/40)
(!!!!) (Recommended Pair) 6CA4 RFT East Germany (Funkwerk) NOS 1970's (48-49/40 and 48-49/40)
(!!!!) (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)
(!!!) (BEST PAIR) 6CA4 RCA NOS 1969-1970's (52/40 and 53/40 x 2 tubes)
(!!!) (Best Single 1959) EZ81=6CA4 Sonotone by Valvo West Germany NOS 1959 (54/40 and 56/40)
(!!!) (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 EZ81) EZ81=6CA4 RFT East Germany NOS 1970's (30 in stock)
(!!!) (BEST VALUE PAIR) EZ81 Radiotron NOS made in India 1963
(!!!) (Recommended Pair) 6CA4 Sylvania NOS 1970's (53-54/40 and 54-55/40 x 2 tubes)
(!!!) (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)
(!) (BEST PAIR) 6CA4 RCA NOS 1960's - 1972 (54-56/40 and 54-54/40) (Wright, Counterpoint, Cary, Zanden)
