Modification of the power module of the Ender 3 printer, which is as quiet as a whisper

The fan noise of the original Ender 3 power supply is a bit harsh, while the actual noise of my unit is only about 53 dB. Using the conventional method - installing other fans and pairing with a step-down converter to adjust the voltage - is certainly feasible... but if you simply use a step-down converter to reduce the supply voltage of the existing fan, it's not only cheaper and doesn't require additional modifications, but it can also deliver excellent quiet operation.

Now, my Ender 3 only makes 37 dB of noise, which is almost a whisper and so quiet that it's almost silent.