(!!!) (Recommended Single) 12AT7 Tungsol rebranded AKRAD "U" getter NOS 1956 (6.2/6.6ma)
(!!!) (Recommended Single) 5691 RCA red base black plates NOS 1957 (2.0/2.1ma)
(!!!) (Recommended Single) 6BX7GT GE "O" getter gray plates 1963 (71/76ma)
(!!!) (Recommended Single) 6BX7GT GE branded Westinghouse black plates NOS "O" getter 1962 (71/79ma)
(!!!) 12AX7=ECC83 Mullard UK "long plates" with "D" getter used/50-60% (0.6/0.7ma Gm=900/1000 - low Gm) (mC1 series)
(!!) (#1 12AU7 Raytheon from 1956) 12AU7 Raytheon gray ribbed plates super large "U" getter halo NOS 1956 (10.4/10.8ma) (High Ma and Gm)
(!!) (#1 5687 Tungsol used 1950's) 5687 Tungsol rebranded IBM bronze plates "U" getter used/very good late 1950's (32.5/39ma)
(!!) (#1 5687 Tungsol used 1961) 5687WA Tungsol bronze plates "O" getter halo used/very good 1961 (33.4/34.8ma)
(!!) (BEST PAIR) 811A RCA NOS and like new 1956-1967 same build (50/36 and 52/36)
(!!) (Best Pinched Waist 1956) E80F=6084 Philips Miniwatt Holland NOS Rugged Reliable Long-Life "Pinched Waist" with "D" getter halo 1956 (3.1ma)
(!!) (Recommended Pair) 6CS7 Sylvania NOS black plates "U" getter 1950's same build (19/11.6ma and 18/11.4ma)
(!!) (Recommended Single 1961) JLRV-12AT7WA=6201 GE Canada gray plates triple mica "U" getter NOS 1961 (9/12ma)
(!!) (Recommended Single) 6201=12AT7WA GE "5 STAR" NOS 1970 (7.6/7.0ma)
(!!) (Recommended Single) 6201=12AT7WA GE "5 STAR" NOS 1970 (8.0/9.2ma)
(!!) (Single) 6201=12AT7WA GE "5 STAR" NOS 1970 (6.0/7.4ma)
(!!) 5692 CBS Hytron brown base used/65% and 80% 1957 (6.6/7.8ma)
(!!) 6136=6AU6 GE 5-Star NOS 1956 (7.7ma)
(!!) 6BX7GT Sylvania "D" getter halo NOS 1950's (44/46ma) (close triode balance)
(!!) 6V6GT Sylvania chrome top NOS 1956 (41.6ma)
(!!) JTL-5687WA Tungsol bronze plates "O" getter used/good 1958 (30/30.5ma)