There is a reason that receivers do not have grounds. Ground Loops through the system. I would not use a XX/3 cord for any receiver or amplifier regardless of ratings. You are bound to run into ground loops whether it is right away or down the road. I had this problem a few years back that took forever to troubleshoot. System worked perfect when I haded it over to the client, then summer came and the A/C caused a big prob in the media room. Scrolling lines and hum throught the spks. Found one of my guys had not used the proper cord for the Denon rcvr. They had lost the original and ran to rad shack.