Is Your HiFi System Humming? Do This First

Diagnosing Hum or Buzz in a HiFi System

The video provides a step-by-step guide to diagnosing and reducing hum or buzz in a HiFi system. It emphasizes that the cause is often a connection, grounding, cable, or placement issue—not necessarily a failed component.

Types and common causes

• 60 Hz hum (or 50 Hz in some regions) is a low drone, often associated with grounding issues or interference from other power sources.
• 120 Hz buzz is harsher and may be related to cables, shielding, or a component’s power supply.
• A ground loop can occur when connected components use different outlets and their grounds have slightly different voltages.
• Electromagnetic interference (EMI) can be picked up by audio cables, especially poorly shielded cables or sensitive turntable connections near power cords, transformers, or other electrical devices.

Troubleshooting guide

1. Check the volume control. If the hum changes with the volume, it may be coming from a source component. If it stays constant, suspect the amplifier or a ground loop.
2. Cycle through amplifier inputs. Hum on only one input points toward that source or its cable. Hum on every input suggests a broader system issue.
3. Disconnect all sources. Leave only the amplifier and speakers connected, then power the system back on. If the hum stops, reconnect sources one at a time to identify which component or connection brings it back. Connect each device’s audio cables first, then its power cord, listening after each step.
4. Check turntable connections. If hum occurs only on the phono input, make sure the separate ground wire is securely connected. A loose tonearm wire at the cartridge may also be responsible.

Suggested fixes

• Use one power strip or conditioner for the audio components to give them a shared ground point. The video identifies this as a common fix for ground-loop hum.
• Separate power and signal cables. Avoid running them alongside or bundling them together. If they must cross, cross them at right angles. Move wall adapters away from sensitive equipment.
• Try properly shielded RCA interconnects if a cable appears to be the source of the noise. Balanced XLR connections can also help reject noise when used in a fully balanced system.
• Consider an RCA ground-loop isolator if simpler measures fail. These use transformers to pass the audio signal while interrupting the ground connection and may be useful with devices such as computers or cable boxes.
• Consider a dedicated power conditioner or regenerator for stubborn cases. These are more advanced and costly options that may filter AC-line noise or isolate power sections.

The overall approach is to isolate the source methodically before buying equipment or assuming the amplifier is broken.

Other content mentioned

The presenter plans to offer a limited number of paid, one-on-one consultations for help with audio setups, turntables, speakers, and room sound. They also reference other guides on speaker matching and placement to help viewers troubleshoot systems and make buying decisions.

Main speaker

The main speaker is the Analogholic channel presenter; no personal name is given in the subtitles.