(!!!!!) (Best Single 1963) CV492=12AX7 Mullard UK NOS 1963 (161 series) (1.3/1.3ma) 1% section balance
(!!!) (Best Value Single) 12AX7=ECC83 Mullard UK ribbed plates used/good 1967 (1.7/0.8ma and Gm=2000/1600) (V1 guitar amp)