In Merlin Blencowes's preamp book, in the grounding chapter, he talks about using balanced RC filtering in the power supply to reduce noise. This would create a new ground reference after the power supply ground that would be elevated a few volts. As anyone tried this or does anyone know of any designs that incorporate this concept? It would require isolating pots from the chassis and if used more than once, at each dropping resistor, carefully grounding each stage of the amplifier to the proper location. I am throwing a basic schematic up here, as an illustration, the values are random, so don't pay any attention to them.