5814A RCA NOS 1970 era slightly microphonic (10.2/11.2ma)
5963 RCA Hewlett Packard gray plates used/good 1960 (8.0/9.2ma)
6189W GE JAN NOS 1973 mica flake inside tube (9.0/9.2ma) 1-2% section balance
6189W GE JAN NOS 1981 (8.4/9.0ma)
6189W GE JAN NOS 1985-1986 (9/11.2ma)
(!!!!) (Best Single) 5814A RCA COMMAND SERIES NOS black plates 1964 (11/11ma) 1% section balance
CV4069=12AU7 Brimar UK NOS with flying leads (no pins)
ECC82=12AU7 Siemens Halske "Long Ribbed Plates" and "O" getter NOS 1958 (10.4/11.8ma)
JG-6189=12AU7WA GE double mica NOS 1963-1964 (10.2/12ma)
JG-6189=12AU7WA GE NOS 1964 (10.2/11ma)
JG-6189=12AU7WA GE triple mica NOS 1963 (8.6/10.4ma)
(!!) (Recommended Single) 5814A=12AU7 Hyperlec Brive France (Holland clone) NOS 1970's rebranded National (10.0/11.6ma)
(!!!!) (Best Mullard Single) 12AU7A Amperex by Mullard UK NOS ribbed plates 1974 (10.6/11.6ma) (DAC, linestage)
(!!!) (Recommended Single) 12AU7A GE NOS 1965 (8.8/8.8ma) 1% section balance
(!!) (Best Value Pair) 12AU7A RCA MEXICO NOS "TOP GETTER" original boxes 1970's (9.2/11.4ma and 9.4/10.6ma)
(!!!!) (2nd Best Mullard Single) 12AU7A=ECC82 Mullard rebranded "GE" ribbed plates NOS 1966 (9.8/11ma) (smooth rich sound)
(!!!!) (Best Bugle Boy Single 1959) 12AU7 Amperex Bugle Boy England (Mullard) long plates with "D" getter like new 1959 (12.4/9.8ma)
(!!!) (Best Single) ECC82=12AU7 Philips Holland branded SONOTONE NOS 1960 (10.6/12ma)
(!!!!) (Best Single) ECC82=12AU7 Telefunken Diamond Bottom ribbed plates like new 1960 (10.6/10.2ma) (same Gm)
(!!!) (Good Value Pair) 12AU7A RCA clear top used/good 1960's (7.8/9.2ma and 7.6/8.8ma)