(!!!) (Best Value Single) ECC82=12AU7 Philips Holland branded SONOTONE NOS 1960 (10.0/9.2ma)
(!!!!) (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 (10.4/11.4ma and 10.0/11.0ma)
(!!!) (Recommended Single) 12AU7=ECC82 Mullard UK branded Philips NOS 1969 (9.0/9.2ma) 1-2% section balance
(!!!!) (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 Single) 12AU7=ECC82 Mullard UK ribbed plates NOS 1972 (12.2/13.6ma) (same Gm) (smooth rich sound)
(!!!) (Good Value Single) JAN-6189=12AU7WA Sylvania NOS 1960 era in white box (8.6/10ma)
(!!!!) (Best Overall Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (11.2/11.7ma) 1-2% section balance
(!!!!!) (2nd 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 1959) ECC82=12AU7 Miniwatt Holland "D" getter 1959 (ct3-delta9I) (11.2/11.4ma)
(!!!!) (Single 1955) 12AU7 Brimar UK NOS gray ribbed plates "D" getter halo 1955 (8.2/10.4ma)
(!!!!) (Best Single #3) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (12.0/10.2ma)
(!!!!) (Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (9.8/8.6ma)
(!!!!) (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
(!!!!) (BEST Pair) 5963=12AU7 RCA NOS ribbed plates 1965-1973 (12.4/12.6ma and 11.4/11.6ma) (Highest mA and Gm)
(!!) (BEST GE Pair) 5963=12AU7 GE branded RCA NOS ribbed plates 1978 (13.0/11.4ma and 12.6/11.4ma)
(!!!) (Best Single 1967) ECC82=12AU7 Philips Holland NOS 1967 (11.2/10.6ma) (same Gm)
(!!!!) (Recommended Single) 12AU7=ECC82 Mullard UK ribbed plates NOS 1970 (10.4/8.6ma)(smooth rich sound)
(!!!) (Recommended Pair) 5963 gray plates NOS 1967-1973 (9.4/9.09ma and 8.4/9.0ma)
(!) ECC82=12AU7 Valvo Holland used/good 75-90% 1968 (7.8/9.0ma)
