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Posted by zarniwoop on February 15, 2005 at 15:44:48:
What I meant was that the splitter's grids are meant to be at +100VDC because they are originally direct coupled from the SRPP stage. Having them near ground would be okay except that the common cathode resistor is 15K (iirc). So you are running the splitter into cutoff because its not biased correctly.. not enough current. You could separate the cathode resistor into a large "tail" resistor and a small bias resistor and connect 1M grid resistors to the junction. Otherwise, to keep that 15K resitor like it is, you would need to connect it to a negative rail instead of gnd.
Other than that, I'm sure the foreplay has enough gain to drive the amp minus the front-end stage. And I probably wouldn't run DC out on ICs either (just make sure you know what you're connecting it to).
re heater current: sorry.. meaning: running other tubes that draw more heater current. 6n1p's, 6bl7's... etc.