I note the replacement is 5mA while the original is .25 mA. Will that be a problem?The fan you have now is a: 40*40*10mm and so is the one I linked; comes with a 2 wire adapter.. should be pretty straight forward, these are standard sizes and Noctua makes nice quiet fans.
just make sure you get the 5v version and not the 12v if you buy elsewhere.
Try slowing down the fan speed as follows: You could try this ==>> here <<==. I cannot attest to them personally but the reviews are good and it would be quick, simple and cheap!I have recently purchased a Dahua NVR4108-8P-4KS2 and found the internal fan (Sunon) was too loud. As the NVR is in my study, I changed the internal fan for a Noctua 40x10mm A-Series Blades with AAO Frame, SSO2 Bearing Premium Retail Cooling Fan NF-A4x10 which has a noise level of 13dB. It was a vast improvement but the noise was still a little intrusive which may be partly caused by the flowing air as it goes through the case as well as the fan.
Has anyone managed to get the machine to be near silent? Is the fan necessary or can it be disconnected?
You could still try the cheaper kit for only 1.19 GBP, replacing the cable you tried with one of the five supplied. It may have a higher impedance resistor to slow it a bit more, you won't know until you try. But a word of caution: many 12 VDC fans won't start below 7.0 volts if power is momentarily removed, you must spin the blade once and you don't want that. The more expensive controller may prevent that.Thank you TonyR. The fan came with a kit which included a cable to slow the fan speed. It did make a difference but the air rush is still audible. Im going to wither have to get used to it or place it a bit further away from my desk.