I want to put a simple "solo boost" ckt in my Home built JCM-800. I robbed a circuit from a Silver Jubilee for the heater rectification. It works, but I think I need to reference ground somewhere in the circuit because there is hum and when I touch the footswitch with my bare hand, the hum goes away.
I built the little daughterboard on the right side of the diagram and I'm using a Rat Shack solid state relay. Like I said, it works, but there's no reference to ground. The neg. side of the caps ties to htr B+, so that's not it.