the hum and the dark bars are audio and video ground loops most likely due to the coax connection. Try detaching the CATV coax and see if it goes away. If it does,then get an isolation transformer as Rex said.
HELP: How to get rid of AC hums and video noise
Hello Audiogoners,
I need help from members of Audiogon more experienced than I am with AC HUMMMMMMMS!!!
My video system is pretty standard: a SACD/CD/DVD player, an audio/video processor, a 5-channel amplifier, 5 speakers and a self-powered subwoofer. Plus of course the various power conditioners & transformers. Oh, I forgot. there are also the VCR, cable box, S-video enhancers and all kinds of wall warts associated with them. Well, maybe the darn thing is not that simple but I still think it is a pretty typical video system.
Anyway, each time I made anything that amounts to more than a minor change in this video system, I have to spend a lot of time chasing down those AC gremlins such as hums in the speakers and/or dark bars moving across the TV screen. Floating and reversing polarity of various AC plugs in even such a standard video system can be very time-consuming and frustrating--i.e. not always successful.
Is there a systematic method to chase down or prevent those AC gremlins?
Or is there perhaps a hum eliminator(like the Ebtech for music equipment) made for RCA connectors?
Any help to alleviate this frustrating experience would be greatly appreciated. THANKS.
I need help from members of Audiogon more experienced than I am with AC HUMMMMMMMS!!!
My video system is pretty standard: a SACD/CD/DVD player, an audio/video processor, a 5-channel amplifier, 5 speakers and a self-powered subwoofer. Plus of course the various power conditioners & transformers. Oh, I forgot. there are also the VCR, cable box, S-video enhancers and all kinds of wall warts associated with them. Well, maybe the darn thing is not that simple but I still think it is a pretty typical video system.
Anyway, each time I made anything that amounts to more than a minor change in this video system, I have to spend a lot of time chasing down those AC gremlins such as hums in the speakers and/or dark bars moving across the TV screen. Floating and reversing polarity of various AC plugs in even such a standard video system can be very time-consuming and frustrating--i.e. not always successful.
Is there a systematic method to chase down or prevent those AC gremlins?
Or is there perhaps a hum eliminator(like the Ebtech for music equipment) made for RCA connectors?
Any help to alleviate this frustrating experience would be greatly appreciated. THANKS.