(!!!) (recommended Pair) 12AU7=ECC82 Mullard UK NOS 1963-1966 (10.8/10.2ma and 11.8/10.7ma) (Same Gm)
(!!!) (Best Value Single) CV4003=12AU7 RFT East Germany NOS 1974 (12.2/12.8ma)
(!!!) (Best Value Single 1958) 12AU7=ECC82 Brimar made for Arkay England ribbed plates 1958 (8.2/10.8ma)
(!!!) (Smooth Single) ECC82=12AU7 Ediswan Valve by Brimar England NOS ribbed plates large "O" getter halo 1962 (11.4/11.8ma)
(!!!) (Best Value Single) CV4003=M8136=12AU7 Mullard UK NOS large "O" getter halo 1962 dirt was over entire tube (10.6/11.0ma)
(!!!!) (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
(!!!!) (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 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 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 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)
(!!!!) (Recommended Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (8.6/11.3mA)
(!!!!) (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)
(!!!!) (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)
(!!!!) (Best Overall Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (11.2/11.7ma) 1-2% section balance
(!!!!) (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
(!!!!) (Recommended Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (9.6/10.8mA)
