(!!!!!) (Best Mullard Pair) 12AX7=ECC83 Mullard UK ribbed plates NOS 1970-1974 (1.2/1.3ma and 1.2/1.1ma) (same Gm)
(!!!!!) (Best Pair 1961-1963) 12AX7=ECC83 Philips Miniwatt Holland NOS and like new 1961-1963 (1.1/1.2ma and 1.2/1.2ma) 1-3% matched
(!!!!!) (Best Pair 1971) 12AX7=ECC83 Philips Holland ribbed plates "O" getter halo NOS 1971 same date codes (1.4/1.4ma and 1.5/1.5ma) (close Gm)
(!!!!!) (Best Single) ECC82=12AU7 Telefunken Diamond Bottom <> smooth plates NOS 1962 (11.0/11.3ma) 1-2% section balance
(!!!!!) (Best Tungsram Single) ECC83=12AX7A Tungsram Hungary branded RCA NOS 1970's (Gm=2000/2300) (1.7/1.8ma) (Highest mA and Gm)
(!!!!!) (Nice Single) ECC82=12AU7 Telefunken Germany <> bottom ribbed plates used/good 1957 (8.5/8.2ma) (strong Gm)
(!!!!!) (Recommended Pair) JAN-CTL6SL7WGT Tungsol NOS brown base gray ribbed plates 1961-1965 (2.1/2.2ma and 2.1/2.3ma) (low noise - very smooth sound) (phono grade)
(!!!!!) (Recommended Single) ECC83=12AX7A Tungsram Hungary branded RCA NOS 1970's (Gm=1700/1900) (1.0/1.4ma)
(!!!!) (Best Pair 1974) 12AU7=ECC82 Mullard Philips UK ribbed plates NOS 1974 1-5% matched (9.8/9.4ma and 9.5/10.5ma) (Rogue, Hovland, Audio Note)
(!!!!) (Best Pair) ECC83=12AX7 Tungsram Hungary branded IEC Mullard NOS 1982 (1.3/1.6ma and 1.4/1.6ma) 1-3% matched (high Gm)
(!!!!) (Best Pair) ECC83=12AX7 Tungsram Hungary branded IEC Mullard NOS 1982 (1.4/1.4ma and 1.4/1.4ma) 1-2% matched
(!!!!) (Best Pair) ECC83=12AX7 Tungsram Hungary branded IEC Mullard NOS 1982 (1.5/1.4ma and 1.5/1.4ma) 1% matched
(!!!!) (Best Value Pair #1) 12AX7A RCA gray ribbed plates NOS 1967-1973 (best tone) (0.9/0.9ma and 0.9/1.1ma) (Fender)
(!!!!) (Best Value Single) 12AU7=ECC82 Philips by Mullard UK ribbed plates used/good 1969 (8.2/8.2ma) 1% section balance
(!!!!) (Best Value Single) ECC83=12AX7 Tungsram Hungary NOS 1980 (Gm=1500/1800) (0.9/1.2ma)
(!!!!) (Best Value used) ECC83=12AX7 Fisher Mullard ribbed plates used/good 1964 (.8/1.2mA Gm=1400/1600)
(!!!!) (Best Value used) ECC83=12AX7 Fisher Mullard ribbed plates used/good 1964 copper grid posts (.7/.8mA Gm=1400/1500)
(!!!!) (Good Value Single) JRP-12AX7 Raytheon Black Plates NOS 1962 (Gm=1300/1500) (0.7/1.0ma)
(!!!!) (Good Value Single) JRP-12AX7 Raytheon Black Plates NOS 1962 (Gm=1300/1600) (0.7/1.1ma)
(!!!!) (Good Value Single) JRP-12AX7 Raytheon Black Plates NOS 1962 (Gm=1500/1700) (0.9/1.2ma)
