@ Hifiman
I just sold a Modwright oppo 105d with the 9.9 power supply which I am sure is very similar. Forget the power cord. Swap out the rectifier tube with Mullard or a Phillips( for 50 bucks you can get a cover with a hole for the larger tubes) Bass response will really improve. I also had a Synergistic Red fuse in the PS and got a slight bump in resolution. I use upgraded PC also but your biggest bang is upgrading the rectifier tube.
good luck!!