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Well, it wasn't a bad idea...
...but it wasn't a good one, either!
It turns out the only way I can use the pentode in a 6AN8 as a preamp is to run it with a much higher HT than I was planning to use - only way I could do this would be to use a higher-voltage PT and run the "power triode" from a much lower B+ *downstream* in the power supply. (With any quiescent plate voltage below 150V, the pentode's curves drop off the chart. Since I'd obviously need a HT of at least 250...
)
Time to find another candidate...or maybe just hang it up for this project.
For what it's worth, here's the schematic I was working with, with values for the relatively non-controversial parts - fairly self-explanatory. If anyone finds a tube that works for this, feel free to run with it, but please share!
...but it wasn't a good one, either!
It turns out the only way I can use the pentode in a 6AN8 as a preamp is to run it with a much higher HT than I was planning to use - only way I could do this would be to use a higher-voltage PT and run the "power triode" from a much lower B+ *downstream* in the power supply. (With any quiescent plate voltage below 150V, the pentode's curves drop off the chart. Since I'd obviously need a HT of at least 250...
)Time to find another candidate...or maybe just hang it up for this project.
For what it's worth, here's the schematic I was working with, with values for the relatively non-controversial parts - fairly self-explanatory. If anyone finds a tube that works for this, feel free to run with it, but please share!
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