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OK . . . So . . . Working Through This . . .

So I need at least a 15k load on each plate.

Then you said: "It is possible to eliminate the predriver, but the grid to plate voltage and grid to cathode voltages in the LTP should remain the same. With a 300 volt B+ supply, one alternative would be to connect the plate resistors to +300" . . .

The same voltages or the same ratio? If I have a B+ of 300v and 15k (or more) on each plate my voltage at the plate will obviously be less than 300v.


". . . tie the grids to ground via a 220K resistor" OK, that I get.

Then: ". . . and move the resistor in the cathodes of the 6SN7s to -115 volts."

I'm confused here. I thought the goal was to keep the voltages the same, why would I need to change the cathode voltage from +125v to a -115v? If that's what's needed though, what size resistor would I need?

And: " Yes, that would require an adiitional supply, but that would also allow you to use fixed bias on the 6B4s."

So just another R-C section or does this supply need to be negative voltage? Where would it be connected? to the grids? Also, would this require the use of fixed bias or could I still use cathode bias as planned?

Also :^) . . . regarding Dave Cigna's defense of the paraphase below, if the LTP has only half as much gain, how much of a problem is using a LTP likely to create since I'm already eliminating one gain stage by using only one 6SN7/two 2C22s per channel?

Thanks for all your collective wisdom and (especially!) patience guys! . . . Charlie




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