more on power supply

The circuit is really simple (see figure).
These tubes are two of 7370 (40V version of 5687WA). Heater is connected to AC input along with 270R (for 117V AC), or 150R (for 100V AC).
It is strongly recommended that average output current does not exceed 20mA, because the average grid current is rated 6.6mA/unit (maximum).