Hummmm on Virgin feed.

[both.of.me]

First of all i would like to thank both.of.me for letting me post up using his account!

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Hi all,

I had Virgin HD installed 'tother day which i am pleased with.

Since then I have noticed what appears to be a mains humm via my speakers... My system is as follows:

Virgin V+ HD Box ---hdmi---> Panasonic G15 LCD ---RCA---> SONOS ZP90 ---RCA---> Dynaudio MC15 Active Speakers.

The virgin coax feed comes in from the road, into a splitter, then one goes to the modem, and one goes to the V+ box.

The humm is present whenever the V+ box is connected and only stops when i disconnect the virgin coax from the box, suggesting that the humm is coming from outside.

At the moment my only solution is to unplug the hdmi from the virgin box whenever i want to listen to music, or play xbox to stop the humm. I thought about connecting over component + rca's from the v+ box but this also seems to carry the humm.

Any ideas, or expertise would be gratefully received!

Thanks.

 

[PJPro]

I think you've got a gorund loop. You need to break that loop to prevent the hum. Posters on other forums seem to suggest a ground loop isolator should be fitted as part of the standard virgin media installation.

See this quote in reference to humming with an AV setup complete with a V+ box...

I have had an engineer out and they simply installed a ground loop isolator which according to the Virgin media engineer should have been installed in the first place.

I have no Humming at all now nothing else needed changing and the chap i spoke to on the phone booked me an engineer as soon as I mention the problem.

One way to confirm the loop would be to use an optical connection between the TV and SONOS. A quick google suggests this should be possible.

 

[micks_address]

what have you got everything plugged into for power? try plugging everything into the same powerstrip if you havent already and see if that makes a difference.. i had a simillar issue where a device with a two pin plug was causing the issue.. i had it plugged into the second socket on a two socket wall switch.. plugging into the powerstrip with everything else solved the issue

 

[both.of.me]

I phoned Virgin about this problem but quite rightly the operator said they didn't have enough knowledge on this to advise properly which was quite commendable. The only thing they could do was to book in a service engineer at the risk that if it turned out to not be their fault I could be charged £99!.....

"One way to confirm the loop would be to use an optical connection between the TV and SONOS. A quick google suggests this should be possible." This would have been the trick but... Sonos only has optical out

Overnight I have resolved this issue with one easy step! I have run a piece of speaker cable from the chassis of the splitter box to a nearby waterpipe...

"You need to break that loop to prevent the hum." Exactly!

Instantly buzz free, blissful.

Thanks for all the responses guys and I hope this could be of use to people in the future!