(!!!!!) (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 1960's) 12AU7 Mullard UK NOS 1965-1966 same build (10.2/12.4ma and 10.6/12.0ma) (Rogue, Hovland, Audio Note)
(!!!!) (Best Single 1961) 12AX7=ECC83 Mullard UK ribbed plates NOS 1961 (161 Series) (1.1/1.1ma and Gm=1600/1700)
(!!!!) (Best Value Pair 1960) 12AX7=ECC83 Mullard UK ribbed plates used/good 1960 (161 Series) (0.8/1.0ma and 0.8/1.0ma) 1-2% matched
(!!!!) (Recommended Pair) 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 Value Single) 12AX7=ECC83 Mullard UK ribbed plates used/good 1967 (1.7/0.8ma and Gm=2000/1600) (V1 guitar amp)
(!!!) (Best Value Single) ECC82=12AU7 Mullard UK NOS 1973 (11.8/10.5ma)
12AT6 Various Brands NOS (4 in stock)
