(!!!) (SINGLE) 12AU7 RCA tall black plates "D" getter used/good 1950's (9.8/8.2ma)
(!!!) (single) ECC81=12AT7 Philips Miniwatt by Mullard UK like new "o" getter 1957 (8.2/7.6ma) (Mitcham plant)
(!!!) (slightly microphonic) ECC81=12AT7 Miniwatt by Mullard NOS 1970 (9.6/10.6ma)
(!!!) 12AU7 RCA tall gray plates "D" getter used/good 1953 (9.2/9.8ma)
(!!!) 12AU7A GE "U" getter low hours/tests like new 1957 (10.0/8.8ma)
(!!!) 12AX7=ECC83 Mullard UK "long plates" with "D" getter used/50-60% (0.6/0.7ma Gm=900/1000 - low Gm) (mC1 series)
(!!!) 12SN7GTA Sylvania branded RCA used/good 1967 (10/12.5ma)
(!!!) 5881 Tungsol used/good 1957 (58ma)
(!!) (Best Single) 407A Western Electric NOS 1979 (47/26 and 50/26)
(!!) (Best Single) 5687 Tungsol rebranded CBS black plates "U" getter NOS 1950's (38/48ma)
(!!) (Good Value) EF86=CV2901 Mullard Blackburn UK "D" getter used/good 1959 (2.4ma)
(!!) (Recommended Single) 6350 Sylvania black plate NOS "U" getter halo 1957 (9/10ma)
(!!) 5Z3G Westinghouse NOS 1957 (59/40 and 61/40)
(!!) 6BL7GTA GE NOS "D" getter 1958 (43ma/53ma)
(!!) JG-12AY7 GE "D" getter 1956 used/good (2.1/2.3ma)
(!) (Best Value) 5Z3G RCA Victor NOS 1940's (48/40 and 49/40)
(!) (Best Value) ECC81=12AT7 Siemens Halske Germany "D" getter 1960 era used/good (8.8/7.5ma)
(!) (Recommended Single) 5Z3G FAA RCA NOS 1962 (56/40 and 56/40)
(!) (Slightly microphonic) JG-5814A GE NOS triple mica "U" getter halo 1956 (10.2/10.4ma) 1-2% section balance (high Ma and Gm)
(Best Single) EC90=6C4 Mullard branded Philips UK box plate NOS 1967 (11ma)
