Rerouted the power and added shield to the signal across and back. Power amp is almost dead quiet with the gain zeroed, and that is with three stages between the pot and PI. Not so bad!
I am going to add swtiching for the last stage. There is no clean sound to speak of, not that I care much, just nice to have an option.
This has been a real success, even if a little problematic using old parts and some design elements of my mule without a real end plan. This place is my favorite place on Earth.
