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I know that an 0A2 wil oscillate if too much capacitance is used shunting it. I use 0.01uF typically. What about an RC network after it. To provide a bit of filtering after the regulator, and to isolate channels, I'm thinking of using a 2.2k resistor and 22.5kuF cap for each of two channels connected to the CCS/SR consisting of two stacked 0A2 and a 10M45S. Each RC will see about 2.5mA. Will this cause instability?

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Walt

It seems that it's true that 0A2s are quiet IF fed by a CCS.
Since the circuit needs 300-310 volts.........bingo. Way simpler than a Camille circuit, and should be perfectly adequate.
But RC filtering afterwards helps with SS regulators, seems like it should also help with a hybrid circuit. As long as the 0A2 doesn't go crazy.

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Walt

Stuart,

Just a small amount of resistance is all you need, what you are proposing is overkill, and will greatly impact the regulation. Besides, you might run into light-of problems with the current being pulled by the charging capacitor. If I read this right, you are using it as a pre-regulator followed by another 0A2 shunt?

You might also want to try the Statistical Regulator of Martin Jones. A string of 5.8V or 6.2V zeners (alot of zeners). Fed with a current source he claims amazingly low noise.

David

David,

I'm doing a crappy job of communicating. Please see attached scribbling to understand what I'm doing.

I'll certainly make the 2.2k smaller,if it will not oscillate. Since this is a simple class A gain stage, I'm not too worried about B+ fluctuations because of high DCR. Still, if 100R or even less will keep the tube stable, I'll do it.

Thanks,

Stuart

Stuart,

Only need about 100 to 200 ohms. If you want/need to have separate supplies as you show, it is better to have two regulators rather than do what you are doing, which defeats the effectiveness of the shunt regulator (increasing regulator impedance).

David