http://www.schematicheaven.com/ampegamps/m12_6v6.pdf Working on a friends Ampeg. On the plates of the PI are a 470k and 510k resistor joined together then fed to a .02 cap then on to a cap/resistor to ground. What does this do? Is it some sort of balancing thing? This is an Accordion amp with a separate channel for an instrument. No, it will not be used for accordion so Id like to eliminate this part of the circuit if its not geared towards guitar. Im guessing I should leave the resistor/cap-to-ground portion since its also attached to one of the PIs grids? BTW, so far, 5 of 5 tested Astron couplers are leaky.