[gregb]

The problem Geoff is the 80 tube will be at full conduction within a second or two of turn on and you could have 450 or more volts at the output of that tube untill the rest of the tubes start to draw current and pull that voltage down. Its not that there will be that high a voltage in normal operation. Its a safety thing so you arn't stessing the filter caps every time you turn it on and reducing the life expectancy.

Gregb