As we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality is its filtering stage. The recommended components for this stage are two ferrite coils (the two coils with a black rubber protection on the pictures below), two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor, yellow component on the pictures below) and one MOV (Metal-Oxide Varistor, yellow component with black rubber protection in Figure 10). Very low-end power supplies use fewer components, usually removing the MOV and the first coil.

The transient filtering stage from this power supply is flawless. The big metallic piece that looks like an ordinary AC connector is in fact a complete line filter. This is the first time we’ve seen a PC power supply using such component. This power supply has one extra ferrite coil and two extra X capacitors but no Y capacitors. We wouldn’t worry about this for two reasons, first the presence of the line filter, which has these components inside, and secondly because after the rectification bridge this power supply has one more X capacitor and two Y capacitors.

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Figure 6: Transient filtering stage (part 1).

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Figure 7: Transient filtering stage (part 2).

In the next page we will have a more detailed discussion of the components used in the EliteXStream 1000 W.