(!!) (slightly microphonic) B309=12AT7 GEC UK black plates "D" getter NOS 1950's (9.6/10.8ma)
(!!!) (Best SIngle 1950's) 12AT7 Brimar UK black plates "O" getter halo NOS late 1950's (11.6/12.8ma)
(!!) 12AT7 Knight by Mullard NOS 1966 (8.8/9.4ma)
(!!) 12AT7WC Raytheon NOS black plates triple mica 1975 (7/11ma)
(!!) 12AT7WC Raytheon NOS black plates triple mica 1975 (7.2/7.4ma)
(!!!) (Best Value Single 1958) 12AU7=ECC82 Brimar made for Arkay England ribbed plates 1958 (8.2/10.8ma)
(!) 6189=12AU7A GE NOS 1975 (9.6/10ma) 1-2% section balance
(!!) 12AU7A RCA CANADA NOS "D" getter halo 1950's tip is chipped (10.0/10.4ma)
(!!) 12AU7A RCA clear top used/good 1960's (7.4/8.6ma)
(!!) 12AU7A RCA clear top used/good 1964 (8.2/8.6ma)
(!!) 12AU7A Toshiba Japan rebranded Raytheon gray ribbed plates NOS 1970's (10/11ma) (same Gm)
(!!) (Best Value Single) 12AX7 Telefunken Germany <> bottom ribbed plates used/good 1960 (0.8/0.8mA and Gm=1400/1400)
(!!) 12AX7 Telefunken Germany ribbed plates used/good 1960's smeared printing (Gm=1300/1700 and 0.9/1.4ma)
(!!) 12AX7A Westinghouse pinched plates "D" getter used/good 1960 era no printing (Gm=1450/1650)
(!!) (SINGLE) 12BH7 CBS branded Arcturus Black Oval Plates large "U" getter NOS 1950's (10.2ma/13.0ma)
(!!) 12BH7A Philco Sylvania gray oval plates "O" getter halo used/good 1962 (6.5/7.3ma)
(!!) 12BH7A RCA gray plates used/good 1960's (8.0/11.2ma)
(!!) 12BH7A RCA gray plates used/good 1970 era (8/9ma)
(!!) 12BH7A Sylvania rebranded Westinghouse NOS pinched plates 1960's 1% section balance (7/7ma)
(!!) 12BH7A Westinghouse black plates "U" getter used/good 1950's (6.2/7.2ma)
