(!!!!) (Holland single 1958) ECC83=12AX7 Triotron Holland "long plates" with "D" getter halo like new 1957 (1.1/1.2ma and Gm=1700/1700)
(!!!) (Best Value Single) 12AX7 Triotron by Philips Canada NOS 1963 (1.3/1.5ma and Gm=1800/1900)(same sound as Holland)
(!!!) (Recommended Pair) 12AX7 Triotron by Philips Holland NOS and Valvo Holland like new 1966-1968 (1.7/1.5ma and 1.5/1.5ma)
(!!) (Best Value) 5Y3GT Raytheon Japan by Hitachi NOS 1960's (56/40 and 53/40)
(!!) (Best Value) 5Y3GT Raytheon Japan by Hitachi NOS 1960's (57/40 and 62/40)
AF7 Miniwatt used/good 1930's
AF7 Triotron used/good 1940's
