Huh, little dissapointed, but try some variations on the theme, for example little cap in front of the first choke... Obviously, I need at least 375 or (400V - "Guinevere"!) for 310V out (2A3/6B4G). In version II, I need about 430V (CLCLC), little first C, say 10-15uF. In the real experiments with 340-0-340V and CLC I get about 420V/100mA with GZ34.