battradio wrote:Separate the two ground lugs on the RCA connectors , and put all the grounding wires on one ground lug , solder a 10 ohm between the two ground lugs on the RCA connectors , this will raise the ground of one rca connector by 10 ohms above ground preventing a ground loop between the the signal source and the amp .
Mark
This is the way I have the amp now. So far it's working best. I still have a very low level hum that is constant and doesn't change with volume. Set up this way the hum is louder on one speaker than the other. I tried the board to ground with the inputs insulated from the chassis. This doesn't work, hum gets worse. I'm going to lift the input shielded cable ground from the input ground tab and see what happens.(shielded cable is only grounded at the input tab, not the board)
I have taken the amp apart and checked all solder joints. Checked hookups/different tubes more than a few times. :)