An optimised power supply for a hi-fi system is essential for enjoying music without any loss of quality. For music to be produced, energy must flow. And in modern households, this energy is no longer the clean, sinusoidal standard it was in past decades. In fact, the domestic mains supply has evolved into a highly ‘active’ system. Switched-mode power supplies, LED lighting, routers, kitchen appliances, charging stations and, not least, photovoltaic systems cause disturbances in the grid. These negative grid interactions include, in particular, harmonics – that is, frequency components above the ideal 50-hertz fundamental frequency – which are generated, for example, by rectifiers as well as by frequency converters and inverters. These superimpose themselves on the mains voltage and lead to an increasing distortion of the sine wave. Also relevant is the so-called flicker effect, which is caused by rapid load fluctuations, for example in industrial applications such as welding systems or arc furnaces, and can manifest itself in the form of visible flickering in lighting. Furthermore, imbalances occur in the mains supply when high-power loads or feeders are operated in single-phase mode, such as instantaneous water heaters, hairdryers or photovoltaic systems. This uneven distribution can lead to a loss of sound quality. 

The power supplies of hi-fi components must therefore not only deliver energy but also combat a diffuse interference field. More sensitive circuits – such as those in D/A converters or preamplifiers – react to this with subtle but audible changes. The soundstage loses depth, fine details become blurred, and the overall sound image appears less defined. It is not a dramatic effect, but rather a gradual loss of precision – comparable to a slightly fogged-up camera lens. In higher-priced segments, manufacturers usually take measures to eliminate such interference. But other components can also respond positively in terms of sound quality when freed from DC components and high-frequency interference. 

If the DC components in the AC voltage are very high, a mechanical transformer hum is often audible, which can occur even in high-quality equipment. Yet the effects go beyond this. A faulty transformer operates less efficiently, generates additional vibrations and affects the downstream power supply. Here, too, it is not a matter of dramatic colouration, but rather a loss of calm, depth and authority in the soundstage that detracts from the enjoyment of music. Those who wish to do so may well put up with this, but for i-fidelity.net such a state is unacceptable, as it spoils our musical and sonic enjoyment. This is precisely where specialised power strips such as the Vincent PF-3 come into play. They filter out high-frequency electromagnetic interference whilst simultaneously and consistently eliminating DC components via integrated DC blockers.