The chassis of the Paramounts needs to be grounded as in the instructions.
One leg of the output transformer should be grounded. It should be the leg that is going to the black speaker lead.
WARNING ! ! ! You need to check with your meter to verify that no leg of the transformer is grounded first. If you ground both legs it will smoke the transformer.
With the amp off measure resistance from the chassis (top plate) to the speaker outputs, either/both. There should be no continuity now. If that is right then you can run a wire from the black speaker output post to the ground lug next to the IEC power input module. (I had to look at the assembly manual) You should have an assembly manual to help you with this.
This wiring is on page 42 of the manual, bottom of the page.