(!!!!) (Recommended Pair) 12AX7 Telefunken Germany <> bottom ribbed plates used/very good 1960 era (1.0/1.2ma and 1.0/1.1ma) 1-5% matched (highest mA and Gm)
(!!!!) (Good Value Single) ECC83=12AX7 Amperex Bugle Boy Holland "long plates" and "D" getter used/good 1958 (1.1/1.1ma and Gm=1350/1350) 1% section balance
(!!!!!) (BEST PHONO PAIR) ECC83=12AX7 Siemens Halske Germany branded SONOTONE NOS 1962 (1.6/2.0ma and 1.6/1.7ma) 1-3% matched (Aesthetix, EAR, Lamm, VTL, Jadis, Nagra)
(!!!!!) (2nd Best Phono Pair) ECC83=12AX7 Siemens Halske Germany branded SONOTONE NOS 1962 (1.1/1.1ma and 1.1/1.3ma) 1-2% matched (Aesthetix, EAR, Lamm, VTL, Jadis, Nagra)
(!!!!!) (Best Value Pair) 12AX7=ECC83 Philips Holland like new 1968 same date codes (1.5/1.7ma and 1.7/1.8ma) (Highest mA and Gm) 1-3% matched
(!!!!!) (2nd Best Pair) ECC803S=12AX7 Telefunken Ulm Germany <> bottom NOS 1961 (1.2/1.3ma and 1.2/1.4ma) 1-2% matched (Nagra, Lamm, VTL, Aesthetix, Diva)
(!!!!!) (Best Pair) ECC803S=12AX7 Telefunken Ulm Germany <> bottom NOS 1961 (1.4/1.45ma and 1.5/1.6ma) 1-2% matched (Nagra, Lamm, VTL, Aesthetix, Diva)
(!!!!) (Best Value Single) ECC803S=12AX7 Telefunken Ulm Germany <> bottom NOS 1961 1-2% section balance (Gm=1550/1600) (1.1/1.1ma)
(!!!!) (Recommended Single) CV4004=12AX7 Mullard box plates NOS 1981 (Gm=1500/1600) (0.9/1.1ma)
(!!!!) (Recommended Single) CV4004=12AX7 Mullard box plates NOS 1981 (Gm=1500/1600) (0.9/1.2ma)
(!!!) (Good Value) 12AX7A RCA gray ribbed plates "O" getter halo NOS 1974 (0.8/1.0mA and Gm=1350/1550) (Fender, McIntosh)
(!!!) (Good Value) 12AX7A RCA gray ribbed plates "O" getter halo NOS 1973 (1.0/0.9mA and Gm=1400/1550)
(!!!!) (Best Pair) ECC83=12AX7 Tungsram Hungary branded IEC Mullard NOS 1982 (1.5/1.4ma and 1.5/1.4ma) 1% matched
(!!!!) (Slightly microphonic Single) CV4004=12AX7 Mullard box plates NOS 1981 (Gm=1400/1500) (0.8/1.1ma)
(!!!!) (Best Single) CV4004=12AX7 Mullard box plates NOS 1981 (Gm=1500/1600) (1.1/1.4ma)
(!!!) 7025 RCA ribbed gray plates used/good 1960's (Gm=1350/1600 and 0.6./1.1mA) (V1 guitar amp)
(!!!!) (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
(!!!!) (Recommended Pair) ECC83=12AX7 Tungsram Hungary branded IEC Mullard NOS 1982 (1.5/1.6ma and 1.4/1.7ma)
(!!!!!) (Best Siemens Pair 1968) CV492=ECC83=12AX7 Siemens Halske Germany NOS 1968 1-2% matched (1.2/1.3ma and 1.2/1.3ma) (best in phono stages and high end preamps)
