Choke input filter?

[Blair]

How big does an input choke have to be?

For example, if I were to take an original ST-70 PA-060 power transformer into a 5AR4 into the original C-354 choke, would there be any issues?

How much capacitance can be added after the choke on a choke input PS before damaging the 5AR4?

Also, it looks like the rule of thumb like the 1.414 multiplier of your secondary is .9 X secondary voltage for a choke input. Is this about right?

Thanks!

Blair

[kheper]

The c-354 would be a mistake; It may buzz and provide poor regulation. A special choke is needed. Some of the higher quality Hammonds are fine, however.

See the link for the math, behind the estimated voltage output.

http://tubes.nekhbet.com/#fulwc

[Blair]

Thank you for the link! Bookmarked!

I have bigger chokes and potted chokes. It is for a preamp, so I figured I might get away with it. I even thought about encapsulating it in resin in case it did buzz, but if I need a beefier choke, then I need a beefier choke:)

Thanks!

Blair

[battradio]

I would go with a choke input , then a as much as 2000uf that would get the voltage down to about 300 volts .