Hi Peter,
Nicely built........
Try this: Disconnect the earth wire of ONE of the two RCA input sockets. Just one, either L or R, not important. Try it - it may work.
BTW, are the earth connections to the speaker binding posts insulated from the panel?
If not, then this could be your problem. There may be a black washer I can't see, but check if there is a connection to the metal of the panel.
Hugh
Nicely built........
Try this: Disconnect the earth wire of ONE of the two RCA input sockets. Just one, either L or R, not important. Try it - it may work.
BTW, are the earth connections to the speaker binding posts insulated from the panel?
If not, then this could be your problem. There may be a black washer I can't see, but check if there is a connection to the metal of the panel.
Hugh