Aboutcleggsan Expertise Consumer Electronics of all kinds. Audio, esoteric audio systems and components, video, tv. Digital equipment for consumer use. Ham radio and automotive electronics. Note: I give advice on tv repair based on general consumer electronics engineering experience but I am not engaged in actual repair of sets. MAKE SURE YOU GIVE THE MAKE AND MODEL NUMBER AND AGE OF THE SET.
Experience Electrical Engineering; recording, broadcasting, design, international standards, tv and radio theory and practice.
Organizations FELLOW of AES (Audio Engineering Society)
Senior Life Member of IEEE (Institute of Electronic and Electrical Engineers)
International Consulting Organization
Publications IEEE Spectrum
Various Consumer Electronic publications
Education/Credentials BSEE
MSCS
MBA
Awards and Honors Famous Engineer for Digital Audio
Question I have a Sony GX47ES receiver that is producing a significant speaker hum. I have just moved to a new (older) house and in setting up the stereo, I have been unable to eliminate this new hum. It is a constant buzzing hum. It persists when the volume is turned all the way down, and does not change in amplitude or frequency as the volume is turned up. The only thing that I have found that changes the hum is changing the source selection on the receiver. The CD, Video, Phono, Tape, and Tape monitor sources all result in a somewhat higher toned buzz than does the Tuner source.
I have isolated the receiver away from all other electronics except the power cord and the speakers. I have tried: several different outlets and surge supressors (the receiver has a two prong plug); attaching a ground from the speaker ground connector to a copper radiator pipe; different speakers and locations in the house... all to no avail.
Am I missing something? Could the receiver have suffered in the move? Might there be a power issue in the house?
Thanks.
Ted
Answer These hum problems are nasty things to track down. Causes are so diverse.
Here are some thoughts:
1. Try reversing the power cord plug. If you find reversing it has a big effect it means there is a grounding problem some where in the system.
2. Try disconnecting the speakers and then connect only one with the shortest possible length of wire (and no there connections to the system except for power).
3. Differentiate between hum and buzz. If it is 60cycle hum it will be a very low frequency. If there is more of a buzz sound to it, that is coming from a power suppply where the filter caps are bad. Replacing the lytic caps is not too expensive nor difficult to do. They could have come loose or failed if the unit has been in storage for a period of time.
4. I know of no house power systems that would cause this problem. (as long as the receiver remains isolated from other apparatus.
5. Make sure the hum is coming from the speakers? Just disconnect all speaker wires and listen for hum coming out of the cabinet of the receiver chassis! (Almost always loose laminations or internal parts within the power transformer - and the can really be loud sometimes!)
Here is a site that has further wisdom in tracking down sources of hum:
