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, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil.

Even though this power supply has two X capacitors and two Y capacitors more than the required, it doesn’t have a MOV, which is a sin on a supposedly high-end product. On the other hand, the coils have a fair better construction than the ones usually used on the power supplies we review.

click to enlarge
Figure 7: Transient filtering stage (part 1).

click to enlarge
Figure 8: Transient filtering stage (part 2).

In the next page we will have a more detailed discussion of the components used in the BFG ES-800.