Power Filters – Filter the power for cleaner, better sound

And isn't that what it is?

In reality, mains power is often not a completely clean and interference-free 50 Hz sine wave. The electrical network can contain many types of interference, “noise and distortion”, such as harmonics, which can be produced by, for example, LED lamps, switching power supplies and many other electronic devices. These harmonics can interfere with and affect the performance of the most sensitive devices. Direct current (DC) can also enter the mains power, for example, due to unevenly operating switching power supplies or poorly designed and/or defective power supplies. The DC component accumulated in the mains power can cause problems for devices with transformers. DC is not very common in a typical home network.

The electrical grid can also experience voltage fluctuations and sudden voltage spikes, which can originate from, for example, high-power household appliances, switching power supplies or even electric car charging stations. Radio and electromagnetic interference (RFI/EMI) can also be transmitted through the electrical grid.

The most common disturbances in the electrical grid are related to high-frequency harmonic voltages (so-called supraharmonics). The increase in disturbances is particularly related to the strong increase in high-power switching power supplies, such as electric car chargers and solar power plant grid feeders.

All of these disturbances in electrical current can degrade the performance of sensitive equipment and shorten its lifespan.

Power filters are commonly used in professional applications. In the studio or live sound, power filters are often necessary. Systems have many different devices connected to different circuits, and therefore interference, grounding and voltage fluctuations are common in these.

In hi-fi equipment, the problems can be of the same type, but the main focus is on how electrical grid interference directly affects sound quality – and how power filters and cleaner, less interference-laden power can potentially improve sound. And this is precisely the topic that is causing a lot of discussion.

So, help with filters?

Power filters reduce various types of disturbances in the electrical network through filtering and protection techniques. They use filters made of inductors and capacitors to suppress high-frequency disturbances, such as harmonics. The filters may also include electromagnetic interference (EMI) and radio frequency interference (RFI) filtering, which helps reduce “noise” from wireless devices such as Wi-Fi and Bluetooth devices. Most power filters also have DC protection, which prevents DC current from being added to the AC current.

Surge protection in power filters protects devices from current and voltage spikes. Some filters also have voltage regulation, which is intended to keep the supply voltage constant in situations where the voltage of the electrical network varies.