be quiet! PowerZone 650W PSU Review

be quiet! are using a 135mm SilentWings fan in this supply – model number BQ SIW3-13522-HF-26. This is the same fan featured in the 750W model of the supply although bequiet! say that each model in the range uses a different fan profile.

It is rated to a maximum rotational speed of 2,600rpm which produces 107.55cfm. It demands 4.32W of power and 0.36A current. These fans use a proprietary surface texture to reduce air turbulences. The company claim that every single fan they sell is tested and tared out individually. They spin the fan blade at very high speeds and then adjust the weight of the fan in areas to compensate for any imperfections. This is a similar principle when you get a new tyre fitted to a car or motorbike wheel.

be quiet! also have a system in place which spins the fan for three minutes after the system is shut down to help remove any excess warm air inside the chassis.

Stripping down this power supply takes a little extra work as the custom moulded plastic panels need to be removed first. Not a complaint, as taking the power supply apart will void your warranty anyway so don't do it. That is why we are here.

Soldering quality throughout seems reasonably good on the main PCB. The PowerZone offers OCP, OPP, OVP, UVP, SCP and OTP protection. The design uses aluminum, not electrolyte capacitors on the modular cable backplate. Aluminum capacitors offer lower equivalent series resistance.

The PowerZone power supply uses a DC/DC design to maintain tight voltage regulation. The 3.3 V and 5V voltages are generated from the 12V rail, after the main transformer.


The supply uses predominately TEAPO capacitors throughout, all rated at 105c. The primary stage capacitor is a 105c TEAPO model, rated 420V 330uF. There are different views on the quality of TEAPO capacitors,  I have seen a few fail over the years, but they are normally fine in well ventilated power supplies and there is no doubt that these will be better than cheaper 85c rated caps from the same company. That said, they certainly don't rate well when compared against the best on the market from companies such as Rubycon, Panasonic or Nippon Chemi Con.

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