EL84 Shunt reg for pre-amp, 85A1?

[tubee]

I am rightnow changing my solid state TL783 regulated PS to a shunt regulator.

It uses a penthode, a BD139 transistor and 75V zener to function with some resistors.

I wonder if it would be possible to use a (OE3) 85A1 gas reference instead of the zener. zener is 75, gas ref. is 85 so that is no problem i guess. Only thing the 85A1 is igniting on about 125V, the zener starts to function immediate when 75V is reached.

But will first build the schematic with a zener see if it works. When i use the gas ref. i have to move the Xformer out of the cabinet for some space for the 2 gas ref tubes.

Any suggestions on the gas reference?

(will post schematic too)

 

[tubee]

Here is an example from my shunt reg. (tubecad)

But then a EL84 penthode is used, and a BD139 extra near the zener.