Looking for opinions on this 6S19P tube based regulator

[jackinnj]

Is there a specific reason for leaving out C4 and reducing C47 from 470n to 47n? I thought that C4 and C47 contribute to noise reduction.

Omitting C4 was an oversight on my part. Putting it in reduces the impedance of the regulator by 6dB (a good thing).

I stepped the values of C47 and it seems to have no effect on output impedance.

Noise measurement in simulation with tube regulators is difficult. I suppose one could Merlin Blencowe's JAES article ("Noise in Triodes with Particular Reference to Phono Preamplifiers" https://www.aes.org/e-lib/browse.cfm?elib=17071) and incorporate it into the spice model, but it is easier to just build the device, then test. With most regulators, "gaining up" the Reference Voltage is the most important source of noise. A single 100V Zener's noise -- will have to measure that!

I think it's a nice circuit, it has good PSRR which is bettered by the input filter, and low output impedance.

(btw, Texas Instruments suggests measuring PSRR without the input filter, not an idea original to me.)

 

[Fully Articulated]

Just simulating this. (6267 is the equivalent of EF86). Output impedance is stable through a range of loads, PSRR -60dB. Note PSRR is measured without the input filter.

Wow, thank you very much for taking the time do this. I should really learn how myself.

Your results are very encouraging.

 

[jackinnj]

Wow, thank you very much for taking the time do this. I should really learn how myself.

Sim then test. if I can do it an my advanced age, you can too.