The PSU is internal ? They just provide the wall power adapter. The adapter definitely isn't the issue, somethings broken internally in the unit itself.
But anyways I got the ifi phono preamp to replace it and it's working better and dead silent. It also feels more...focused, as it's built specifically to be a phono preamp, it has multiple gains depending on the cartridge used and a rumble filter. I have this plugged in directly to the Nad M10 and everything is working great. I can't say I notice an audible difference between sound quality between the two, maybe a bit punchier bass with the ifi ? Hard to say without doing direct a/b switching. Thanks for the help