My power supply recently died so I bought a Cloudray supply. Installed and it made a noise when under load / powering the tube; the noise got louder the more power was applied and it requires more power and more passes to cut the same material I was previously cutting. I have a video of the noise but can’t seem to upload.
It’s an electric noise not sure how to describe
You should have cloudray replace it. It shouldn’t make noise and loose power… 
Sorry I forgot to mention, cloudy have replaced the supply; both supplies I have make exactly the same noise. I am going to run the machine in pitch black later to see if the supply emits any light where it shouldn’t
Are/can you monitor current through the tube?
I have a basic ammeter / electric tester?
My machine has a digital meter on the power supply and I have added a 30ma meter on the deck.
Considering the supplies have been replaced, I don’t really know what other item would cause a noise.
There’s always the possibility that you got two bad lps
I’ll have to think on it… 
You may have a shielding / insulation issue with the High Voltage lead coming off of your laser PSU. This would cause arcing to the machine chassis. If this is the problem, your original PSU may not have been bad (or this killed it and will kill the new ones as well).
Maybe your issue resembles what is described in one of these posts: