(!!!!!) (Recommended Single) KT88 GEC UK used/tests like new 1960's (137.6ma, Gm=10,800)
(!!!!) (Best Pair) 6J5G ATES ITALY round black plate NOS 1950's (8.8ma and 8.8ma) 1-2% matched
(!!!!) (Recommended Pair) CV1067=6J5G GEC (M-O Valve) UK coated glass NOS 1950's (7.2ma and 7.2ma) 1-2% matched
(!!!!) (Recommended Pair) CV1067=6J5G GEC (M-O Valve) UK coated glass NOS 1950's (8.0ma and 8.0ma) 1% matched
(!!!!) (Recommended Pair) CV1067=6J5G GEC (M-O Valve) UK coated glass NOS 1950's (9.9ma and 10.4ma)
(!!!!) (Recommended Single) 5Z4G Brimar UK black plates NOS 1950's (54/40 and 54/40) (recommended for Audio Note)
(!!!!) (Recommended Single) 5Z4G Tungsram UK black plates NOS 1950's smaller getter (56/40 and 56/40) (G9 Audio preamp) (Best sub for Russian 5Ц4С / 5U4C Russian)
(!!!) (Best Single) 6V6G GEC UK branded Haltron NOS coated glass NOS 1940's (49ma)
(!!!) (Best Single) KT88 Genalex England NOS 1967 rebranded SC1000 Stromberg-Carlson (147ma)
(!!!) (Single) 6J5G Sylvania engraved base black oval plate used/very good 1930's (8.0ma)
(!!!) (Single) KT66 Osram UK brown base used/good 1950's rattle inside base (67ma)
(!!!) 5Z4G Brimar UK gray plates used/good 1960 era (60/40 and 62/40)
(!!!) 5Z4G Brimar UK gray plates used/good 1960 era (63/40 and 64/40)
(!!) (Best Single) KT66 GEC England NOS 1962 (76.5ma)
(!!) (slightly microphonic) B309=12AT7 GEC UK black plates "D" getter NOS 1950's (9.6/10.8ma)
(!!) KT66 GEC UK used/good 1962 missing guide pin (79.6ma)
(!) U19 GEC UK NOS 1960's (1 pair)
(Display Tube) KT66 GEC 1960's (WEAK TUBE: LOW Ma and LOW GM) - for display purposes only
(Display Tube) KT66 GEC 1971 purple gas - for display purposes only