LA2 (no, not again!) Negative Feedback

[CJ]

I now am running my LA2 with a 6SN7 driving a 6SN7 for the line amp. It sounds wonderful. Larger current requirements brought the B+ way down to the point where I only had 50 volts on the plates of the voltage amp, due to the 68 K voltage dropping resistor in the power supply, so I stuck a 10 K in there.

My question is, now that I am running a tube with an amp factor of 20 instead of the stock amp factor of 100 with the 12AX7, should I change the negative feedback network to match up with the 6SN7 voltage amp a little better.? Is so, what should I do, just play with the resistors a bit or leave it alone.
Thanks!

here is the circuit:

 

[PRR]

If it sounds wonderful, why mess with it?

10K seems low even for 6SN7. On paper, go back to 47K or 100K, then reduce the cathode bias resistors. That fouls your feedback, though: I'd leave the first stage running at whatever bias it wants to sit at, and just optimize the second stage so the plate sits at 1/2 to 2/3 of B+.

 

[CJ]

The 10K is in the power supply. I am still using 100 K plate resistors.

I drew in the 10K 2w in the above schematic - R16.

Also, I seem to get more bass with the 6SN7. Can not figure out why. Maybe feedback, or maybe the higher current in the voltage amp?

I will tweak that second stage. Thanks!