(!!!!!) (Best Single #1) 12AU7 Mullard UK "long plates" and "O" getter 1958 low hours/like new (10.8ma and 11ma) (High mA and Gm)
(!!!!!) (Best Single 1958 #2) 12AU7 Mullard UK "long plates" and "O" getter 1958 used/very good (9.4ma and 9.6ma)
(!!!!!) (Best Single) ECC82=12AU7 Telefunken Diamond Bottom <> smooth plates NOS 1962 (11.0/11.3ma) 1-2% section balance
(!!!!!) (Good Value Single) 12AU7=ECC82 Mullard UK long plates "O" getter halo used/good 1958 (9.0/8.8ma)
(!!!!!) (Holland Single) 12AU7 Pope Holland NOS 1971 dimpled disc halo (12/13.4ma)
(!!!!!) (Nice Single) ECC82=12AU7 Telefunken Germany <> bottom ribbed plates used/good 1957 (8.5/8.2ma) (strong Gm)
(!!!!!) (Recommended Pair) 12AU7=ECC82 Philips Mullard UK NOS 1966-1974 same build (10.6/10.3ma and 11.7/10.4ma) (close Gm matching) (Rogue, Hovland, Audio Note)
(!!!!) (Best CV4003 Quad) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (8.4/9.0, 8.4/9.0, 8.4/8.8, 8.4/8.8mA)
(!!!!) (Best Overall Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (9.6/9.6ma and 9.4/9.8ma) 1% matched (can make a quad with another pair)
(!!!!) (Best Overall Quad) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (8.8/8.8, 8.8/8.8, 8.6/8.8, 8.6/9.0mA)
(!!!!) (Best Overall Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (11.2/11.7ma) 1-2% section balance
(!!!!) (Best Overall Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (12.2/12.8ma) 1-3% section balance (highest mA and Gm)
(!!!!) (Best Pair #2) ECC82=12AU7 Philips Holland NOS 1971 (10.8/11ma and 10.0/10.4ma)
(!!!!) (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 Quad) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (8.8/9.5, 8.8/9.4, 9.0/9.3, 9.0/9.4mA) (Highest Gm 1-2% matched)
(!!!!) (Best Single #3) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (12.0/10.2ma)
(!!!!) (Best Single) 12AU7=ECC82 Mullard UK ribbed plates NOS 1972 (12.2/13.6ma) (same Gm) (smooth rich sound)
(!!!!) (Best Telefunken Single 1966) ECC82=12AU7 Telefunken Germany <> bottom smooth plates NOS 1966 (9.3/10ma) (High Gm)
(!!!!) (Best Value Pair) 12AU7 Philips Holland NOS 1971-1972 dimpled disc halo (10.2/10.6ma and 11.2/11.6ma)
(!!!!) (Best Value Single) 12AU7=ECC82 Mullard UK ribbed plates like new 1965 (10/12.8ma) (smooth rich sound)
