The RM750x incorporates the NR135L 135mm fan. This is a rifle bearing fan rated at 0.22A. Corsair claim that a rifled bearing fan will provide longer life and quieter operation than ‘most’ ball bearing fans. The blades of this fan are said to be properly balanced to help prevent resonance at higher speeds. There is a little plastic flap over part of the fan, to forceably direct the airflow across the hotter running components.
This is a CWT design for Corsair, and the build quality is very high indeed. Soldering is without fault and the component selection throughout is excellent. The layout seems well thought out for surface cooling too.
Corsair make the point that they have invested a lot of time into ensuring these units do not exhibit any ‘coil whine’. This can be caused by poor winding of a transformer or coil. Also the conducting and insulating layers of a capacitor can vibrate excessively if the components are not wound properly. These vibrations can lead to audible noise that many people class as ‘coil whine’.
Corsair are using 105c rated Japanese capacitors on both primary and secondary stages. In the primary stage there are two different sized KMR series Nippon Chemi Con capacitors – one is rated 400v 470uF and the other 400v 390uF. This brings the total to 860uF.