In the past, analog amplifiers were used in high output audio equipment to emphasize audio quality, but in recent years, digital amplifiers have improved in terms of audio quality and have become popular in home audio as well.
Due to the switching noise that occurs in digital amplifiers, noise that exceeds the EMC standards can be emitted into the space around the cable connected to the speaker. Noise suppression using capacitors and inductors is implemented to solve this noise problem.
* EMC standards: Noise regulation standards prescribed by various countries (examples include VCCI in Japan, the FCC in the United States, and the EN standards in Europe)
Murata is commercializing the NFZ series of audio line filters as noise filters that can suppress unwanted noise while maintaining audio quality. This section introduces noise problems in home audio and their solutions.