Enermax NAXN 850W Modular Power Supply Review

As soon as you open the power supply, the first thing you will notice is the fan. This is a Globe 1500RPM PMW fan that operates very quietly- it is impossible to hear unless you put your ear to it! The fan employs Enermax’s ‘HeatGuard’ technology which means that the fan stays on for between 30 to 60 seconds after the computer has shut down to dissipate heat that is left inside the unit.

The NAXN uses a fantastic heatsink design that increases surface area massively to give the fan an easy job. Also, there are more heatsinks than usual because components which would normally share a heatsink now have their own. Again, making the cooling more efficient.

The first stage inside a PSU is the transient filtering. This is where the unit filters the AC power coming from the mains so there is less noise which is extremely important as it impacts the efficiency and safety of the later stages, which is partly the reason you see people investing hundreds of pounds in UPS systems which do a similar job. To do this, a system of capacitors, ferrite coils and a metal oxide varistor is used. The quality of this stage is determined by the number of components doing the filtering. Many generic units will only have a singular capacitor or won’t have a metal oxide varistor (MOV). The first part of the transient filtering has an MOV and two capacitors, there are more on the PCB but I had trouble determining the transient ones from the other components for this unit.

Capacitors are one of the more volatile components when it comes to electronics and can leak or even explode when mistreated or exposed to high temperatures. Ever heard a PSU die with a pop? Chances are- it’s a capacitor! The capacitors used here are 100% Japanese from Rubycon and are rated at 105C.

The modular daughterboard is safely insulated and has a great soldering quality. There are capacitors on this board to improve stability.

I have to add that this is probably the best interior build quality I have ever seen! The only PSU I have seen that comes close is the HX1050, Sirfa have really proved themselves here!