hi i have the SHERWOOD RD-8108R receiver and the gigaworks g500 pc speakers. i have a 3.5 mm at 1 end and 2 rca at the other end right and left. when i plug the 3.5mm end in to my sub and 1 of the rca to my pre amp an my amp i just get a humming sound i have tried both rca connectors both the same.but if i plug the white 1 into my pre amp and the red 1 to tape play it works.what i want to know if this is safe to do am i breaking my SHERWOOD amp by doing this will this be using more power from my amp thanku for any help.