12AT7 Mullard branded Amperex Globe Logo 1967 used/good (6.6ma/7.2ma)
12AT7 RCA Black Plates "D" getter used/good mid-1950's
12AT7 Siemens Halske Germany D getter NOS 1957 (6ma/8ma)
12AT7=E81CC=6201 Siemens triple mica NOS 1971 (12/15.8ma)
12AT7=ECC81 Mullard low hours/like new 1970 (8.0/8.4ma)
(!!) (SINGLE) M8162=12AT7WA Mullard UK copper grid posts NOS 1963 (9.2/13.5ma)
12AT7WA Raytheon black plates - triple mica - O getter halo 1960's mis-matched triode sections (7/12ma)
12AT7WA=6201 GE NOS gray plates 1965 (7.8ma/10.6ma)
12DT8 RCA black plates NOS 1970 (23.0/24.4ma) (highest Ma and Gm)
12DT8 RCA gray plates NOS 1970's (12.2/16.4ma)
12DT8 RCA gray plates NOS 1970's (12.6/14.0ma)
(!) (Best Value) 12AT7WA Raytheon black plates - triple mica - O getter halo 1965 era like new (8.5/9.2ma)
(!!!) (Recommended Single) 12AT7 Tungsol rebranded AKRAD "U" getter NOS 1956 (6.2/6.6ma)
(!!) (BEST VALUE) 12AT7 Telefunken Germany used/good 1965 (9.2ma/8.4ma)
6201=12AT7 GE "5 STAR" used/good triple mica "U" getter halo, copper grid posts, gray plates, 1957 (6.2/7.8ma)
(!!) (Recommended Single) 6201=12AT7WA GE "5 STAR" NOS 1970 (8.0/9.2ma)
6679 (see 12AT7)
(!!!!) (Best RCA Single 1964) 6201=12AT7WA RCA black plates NOS 1964 (9.8/7.4ma) (best tone)
(!!!!) (Recommended Single) 12AT7 RCA NOS 1965 (9.5/8.7ma)
(!!!) (Best Value Pair) JAN-12AT7WC GE gray plates NOS 1970 (7.0/7.6ma and 7.0/8.2ma)