(!!!) (Good Value Single) GL-5751 GE "5 Star" black plates triple mica D getter 1954 used/good (2.1/2.3ma)
(!!!) (Recommended single 1954) 5670 GE triple mica with D getter halo NOS 1954 (7.4/8.2ma)
(!!!) (SINGLE) 12AU7 RCA tall black plates "D" getter used/good 1950's (9.8/8.2ma)
(!!!) (SINGLE) 5670 RCA NOS "O" getter triple mica 1960 era used/good (6.6/7.2ma)
(!!!) (SINGLE) 5751 Hitachi Japan glossy black ribbed plates triple mica double D getters 1960's (2.2/2.6ma)
(!!!) (Single) JG-5670 GE D getter halo 1956 like new (8.3/10ma)
(!!!) (Single) JHS-5670 Sylvania NOS 1966 (7.0/6.8ma)
(!!!) 12AU7 RCA tall gray plates "D" getter used/good 1953 (9.2/9.8ma)
(!!) (Recommended from 1950's) 12AT7WA Sylvania gray plates triple mica "D" getter halo tests like new 1950's (9.4/12.0ma)
(!!) (Recommended Single) E81CC=12AT7 Siemens Germany double mica NOS 1975 (11.6/13.6ma) (strong Ma and Gm)
(!!) (Recommended Single) JG-5751 GE gray plates double mica "O" getter NOS 1965 (2.1/2.1ma)
(!!) (Single) 6060=12AT7 Brimar Thorn UK square black plates triple mica large "O" getter halo 1957 used/good (7.2/7.6ma) (Premium low noise 12AT7)
(!!) (Single) 6060=12AT7 Brimar Thorn UK square black plates triple mica large "O" getter halo 1960 NOS (6.4/8.4ma) (Premium low noise 12AT7)
(!!) 5751 Sylvania misbranded 12AX7WA NOS 1960's (1.9/1.9ma)
(!!) 5751W1 Sylvania triple mica "O" getter halo used/good early 1960's misbranded 12AX7WA (1.8/2.0ma)
(!!) 5814A RCA black plates used/good 1964 (7.2/8.4ma)
(!!) 6350 RCA NOS triple mica "U" getter NOS 1960 era (12.8/13.2ma)
(!) (1950's Single) 12AT7WA Sylvania black plates triple mica "D" getter used/good 1950's (6.2/7.0ma)
(!) (slightly microphonic) 5751 Sylvania rebranded RCA black plates triple mica "D" getter used/good 1950's (2.0ma/2.2ma)
(!) (slightly microphonic) 6072 GE branded RCA triple mica black plates "O" getter halo 1960 used/good (2.0/2.0ma)
