I recommend you try some combinations and let your ears decide. Here are some general preferences. All equipment should be on the same phase of the AC. Digital gear should be on a different dedicated line than other sources and the pre. Amps should be on their own dedicated line.
You 4 plug outlet is probably 1 line. What makes you think it is dedicated? Look to see if all circuts are on the same phase in the main panel.
So, your best solution is not obvious and will take some trials. I suggest you start with the amps on the 4 plug outlet, the Hydra on the 4 plug outlet, and the transport/pre/dac on the Hydra. That puts everything in phase, and gives some conditioning to the source and pre.
Have fun...