(!!!!) (Best Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (10.2/11.2ma and 10.4/11.2ma) 1-2% matched
(!!!!) (Best Pair) ECC82=12AU7 Philips Holland NOS 1972 (12/12ma and 11.2/11.8ma) (Highest mA and Gm)
(!!!!) (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) ECC82=12AU7 Telefunken Diamond Bottom smooth plates NOS 1964 copper grid posts (10.6ma/10.2ma) 1-3% section balance
(!!!!) (Best Single 1956) 12AU7=ECC82 Amperex Holland "long-plates" large "D" getter with crossbar like new 1956 (9.2/8.2ma) (rare)
(!!!!) (Best Single 1965) ECC82=12AU7 Miniwatt Holland like new 1965 (9.4/9.4ma) 1% section balance
(!!!!) (Best Single) 12AU7=ECC82 Mullard UK ribbed plates NOS 1972 (12.2/13.6ma) (same Gm) (smooth rich sound)
(!!!!) (Best Single) ECC82=12AU7 Telefunken Diamond Bottom ribbed plates like new 1960 (10.6/10.2ma) (same Gm)
(!!!!) (Best Value Single) 12AU7=ECC82 Mullard UK ribbed plates like new 1965 (10/12.8ma) (smooth rich sound)
(!!!!) (Good Single 1950) 12AU7 Sylvania black plates "D" getter NOS 1950 (11/12.8ma)
(!!!!) (Holland Single) 12AU7 Philips Holland NOS 1971 dimpled disc halo (10.2/10.6ma)
(!!!!) (Holland Single) 12AU7 Philips Miniwatt Holland like new 1961 large "O" getter halo (9.6/11ma)
(!!!!) (Long Plate Single) 12AU7 Mullard Heath UK long plates "O" getter used/good 1959 (8.8/9.0ma)
(!!!!) (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)
(!!!!) (Recommended Pair) 12AU7A=ECC82 Mullard rebranded "GE" and "Zenith" ribbed plates NOS 1966 (9.8/11ma and 10.4/10.5ma) (smooth rich sound)
(!!!!) (Recommended Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (10.4/11.4ma and 10.0/11.0ma)
(!!!!) (Recommended Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (9.0/10.4ma and 9.4/10.0ma) 1-3% matched
(!!!!) (Recommended Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (9.6/8.8ma and 9.4/9.0ma) 1-2% matched
(!!!!) (Recommended Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (9.6/9.4ma and 9.8/9.6ma) 1-3% matched (same Gm)
(!!!!) (Recommended Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (9.8/11ma and 10/10.9ma) 1-2% matched
