Loud PSU after build?

[DenverAU]

I have just recently built a PC (https://au.pcpartpicker.com/list/wDwVMc) and everything seems to be working fine on the technical end. I have a slight problem though. The PC noise seems to be quite noticeable when its idle and nothing is running. I've spent some time listening to it, and it seems like the loudest part is coming from the power supply. The noise isn't mechanical, I'm 80% sure its the PSU fan.

Is my PSU faulty or have I likely done something wrong? I have also seen in reviews that the GPU I have can be quite loud, but I'm relatively confident that it's not contributing to all the noise.

I'd really appreciate the help, even if you link me a resource that you'd think that would be helpful (I cant seem to find any info that is specific to my situation).

Thanks

 

Update: a sound recording of the sound is attached (online link: https://voca.ro/4BSk3Z1lK13) 

New Recording.m4a

Edited August 28, 2020 by DenverAU

[Cyracus]

the noise, high pitched or low pitched? High pitched buzzing from gpu or psu is typically coil whine.

[DenverAU]

It is a constant low pitch, but there is a faint lighter pitch if you listen carefully. However the lower pitch is much more noticeable  

[DenverAU]

3 hours ago, Cyracus said:

the noise, high pitched or low pitched? High pitched buzzing from gpu or psu is typically coil whine.

Here is a recording of the sound

 

(https://voca.ro/4BSk3Z1lK13 in case attachment fails)

New Recording.m4a

[Cyracus]

Sounds to me like there could be an obstruction inside (inspect with penlight from rear, don't open, danger shock hazard inside psu) if there's debris attempt to dislodge by turning the psu over and around and any which way, and convince it to fall out the fan area. (it could just be the whoosh of the fan blowing past the components, they too are an obstruction after all)
The high pitched noise sounds like coil whine to me, you could give the psu warm air to suck in while it's at low load to speed up the fan without changing other operational parameters, if the whoosh gets louder but the whine stays the same then it's not the fan. If you put it under a load with sporadic power draw and that high pitch warbles it's definitely coil whine.