How to Eliminate Relay Noise in Audio Systems > 자유게시판

Relay noise in audio applications can be a annoying problem that injects disruptive electrical noise into your audio output. This transient artifact typically occurs when electromechanical switches activate or deactivate, causing rapid current surges that interfere with low-level signal stages. While relays are useful for switching high-power signals, their physical switching mechanism makes them highly susceptible to voltage spikes.

To eliminate switching artifacts, start by selecting an appropriate relay technology. semiconductor switches are often a preferred solution for audio because they have zero mechanical components and transition without arcing, reducing the likelihood of voltage spikes. If you must use a mechanical relay, select one with a optimized winding design and consider using a damping network—a simple resistor and capacitor in series—across the relay coil to dampen the back emf generated during switching.

Additionally, ensure proper grounding and shielding. Keep relay power and control lines away from low-level input circuits and use braided shield cables where possible to reduce RF coupling. Place the relay as far as practical from mic and line-level inputs, and consider adding a small ferrite bead on the relay power line to attenuate RF emissions.

Power supply filtering is also vital. Use bypass capacitors near the relay’s power input and consider a isolated audio power source for the audio section. Finally, implement digital timing delays if the relay is controlled digitally, so that switching happens during silent intervals in the audio signal.

By combining these techniques—selecting the right relay, filtering transients, isolating signals, and synchronizing with audio silence—you can effectively suppress switching artifacts and maintain clean, professional audio quality.