The NX-4090 from Nexus
The Nexus NX-4090 is a 400 W power supply compliant with the ATX12V 1.3 standard. It uses a 120mm fan that is extremely quiet in normal mode, but under maximum load a loud humming and "ringing" can be heard. This is attributable not to the power supply's fan but to its electronic components. The power supply features a 115V-230V switch - users should be sure to note its position before operating the device!
Careful! You must check the position of this switch prior to operating the unit for the first time