(!!!!!) (Best Siemens Pair 1972) E83CC=12AX7 Siemens Halske Germany NOS triple mica 1972 printed in 1976 (1.0/1.3ma and 1.1/1.3ma) (best in phono stages and high end preamps)
(!!!!) (BEST SIEMENS PAIR) EL84 Siemens Halske Germany NOS 1969 (47.5ma and 50.4ma)
(!!!!) (BEST SIEMENS PAIR) EL84 Siemens Halske Germany NOS 1969 (57.5ma and 60ma)
(!!!!) (Best Siemens Pair) EL84 Siemens Halske Germany used/test like new 1971 (48.2ma and 48.5ma) (High Gm)
(!!!) (Best Value Single) 12AX7=ECC83 SIEMENS HALSKE GERMANY like new 1966 (1.0/1.1ma)
(!!) (Best Single 1966) ECC83=12AX7 Siemens Halske Germany NOS 1966 (162 Series) (Gm=1500/1600 and 1.0/1.1ma)
(!!) (Good Value) 12AX7 Siemens Halske Germany rebranded "BOGEN" used/good 1960 (161 Series) (Gm=1400/1500 and 0.8/0.9ma)
(!) (Good Value) ECC83=12AX7 Siemens Halske Germany used/good 1960's in white box (Gm=1500/1700)