(!!!) (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
(!!!!) (Recommended Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (9.8/11ma and 10/10.9ma) 1-2% matched
(!!!!) (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 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 (9.4/11.3mA)
(!!!!) (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)
(!!!!) (Recommended Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (10.4/11.4ma and 10.0/11.0ma)
(!!!!) (Single 1955) 12AU7 Brimar UK NOS gray ribbed plates "D" getter halo 1955 (8.2/10.4ma)
(!!!!) (Best Overall Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (10.8/11.2ma) 1-3% section balance
(!!!!) (Best Overall Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (13/12.8ma) (Highest mA and Gm)
(!!!!) (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
(!!!) (Single) CV4003=M8136=12AU7 Mullard branded Philips NOS 1975 (8.8/8.2ma)