Hi, I have a Harmon Kardon Citation V that I rebuilt with McShane kits that I need some ideas/help on how to properly do the ground scheme to get things quiet. So far my efforts have resulted in different levels of hum. I've read and read theories on how to wire it but I get confused implementing the ideas as described and feel that i'm going in circles at this point. How should the RCA inputs be grounded with isolated jacks? What parts of the power supply should be grounded to each other and then to maybe a star or bus? Should the power supply join a star ground connecting to the rest of the amp and what parts of that should be joined before they go to the star?
Anyway, the parts of the amplifier that need to be grounded are the power, the two inputs, two driver boards, the power tubes which stock are separated into grounded pairs, bias supply, two 33ohm resistors going to the heaters, and a added circuit for DC heaters for the 12BY7's. I have the power chord grounded to a bolt of the power transformer. Any guidance, help, thoughts, encouragement are greatly appreciated.
Below is a Citation V's schematic. It looks like that it's based on a Mullard 5-20 type circuit.
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Dan