The Marantz uses a C18 IEC without a ground. The three prong IEC is a C14 and will fit into the C18 socket. There will be no electrical issues.
2 prong power cable
Never paid much attention until recently but my Marantz PM11S3 has a 2 prong power cable. Anyone know of upgraded power cables with only 2 prongs. I'd like to replace the stock cable for one that will help with imaging and a nudge toward neutrality since the Marantz tends a teeny bit toward warmth. Thanks.