Received my Snapmaker last week and after the first power up I was suprised how ridiculously loud the PSU is. Also designed (yet another) fan bracket for the exhaust fan without the need of modificating the back plate. Thought I might share with you::
Also made a short video for comparison of the stock fan to a Noctua fan if someone who hasn’t received the Snapmaker is wondering what everybody is talking about… 
After silencing the exhaust the PSU wasn’t as quiet as expected so I took a closer look at the power supply. Installed is a 350W “Great Wall” PSU, the venting holes made quite some whistling noise.
First i thought of printing a new cover but since it is a low profile PSU without much room to the top of the enclosure I wouldn’t be very comfortable with a (thermo)plastic cover so close to heat sources.
So instead I removed this venting hole part completely and sanded the edges down.
Now the whistling noise is gone but still have to replace the integrated fan to quiet it down to a reasonable sound level.