(!!!) 12AU7 RCA tall gray plates "D" getter used/good 1953 (9.2/9.8ma)
(!!!) 12AX7=ECC83 Mullard UK "long plates" with "D" getter used/50-60% (0.6/0.7ma Gm=900/1000 - low Gm) (mC1 series)
(!!) (Best Pair) 6J6A Tungsol NOS "D" getter 1961 (9.4/10.5ma and 9.0/11.4ma)
(!!) (Best Single) 12AU7A Tungsol tall ribbed plates NOS "O" getter halo 1960 era (9.8/9.6ma)
(!!) (Best Single) 12AU7A Westinghouse gray plates "O" getter halo 1960's NOS (10.6/11.2ma)
(!!) (Best Single) 407A Western Electric NOS 1979 (47/26 and 50/26)
(!!) (Good Value Single) EL84 Zenith Holland "D" getter used/65% 1959 (35ma)
(!!) (Good Value Single) EL84 Zenith Holland "D" getter used/very good 1958 (41ma)
(!!) (Recommended Pair) 6J6A Tungsol NOS "D" getter 1961 (7.5/8.8ma and 7.8/9.2ma)
(!!) (recommended single 1957) CV455=12AT7 Mullard "D" getter like new 1957 (12.4/8.6ma)
(!!) (slightly microphonic) 12AU7A Raytheon black ribbed plates "D" getter halo black coated glass 1951 (8.8/9.6ma)
(!!) (slightly microphonic) B309=12AT7 GEC UK black plates "D" getter NOS 1950's (9.6/10.8ma)
(!!) 12AT7 Brimar black plates NOS/70-75% 1955 (5.6/5.8ma)
(!!) 12AX7A Westinghouse pinched plates "D" getter used/good 1960 era no printing (Gm=1450/1650)
(!!) 6BL7GTA GE NOS "D" getter 1958 (43ma/53ma)
(!) (Best Value) ECC81=12AT7 Siemens Halske Germany "D" getter 1960 era used/good (8.8/7.5ma)
(!) 12AT7 Mullard Heath "D" getter used/good 1959 (6.4/7.6ma)
(!) 12AT7 Mullard Heath "D" getter used/like new 1960 (8.0/9.6ma)
(!) 12AT7 RCA black plates NOS D getter halo 1950's, slightly microphonic (13/16.4ma) (high Ma and Gm)
(slightly microphonic tube) 12AT7 Brimar UK black plates "D" getter halo copper grid posts used/good 1955 era (7.2/8.4ma)
