Optical Cable Volume Fluctuation


Standard Member
Hi, I have a strange issue that searching has not given an answer to.

My 4 year old Panasonic plasma TX-P42C2B has an optical out. I have this connected to an Onkyo LS3100 2.1 system.

I have Sky+ (Not HD)(connected to TV via Scart) and last week had BT YouView+ (connected to TV via HDMI) installed. When the Onkyo was fairly new, the sound through Sky would fluctuate, sometimes a little, sometimes a lot. This fluctuation was while watching a single channel, not between channels and not between programmes. It would happen over periods of seconds.

More recently this fluctuation seems to have settled, but now the YouView+ seems to have a very significant volume fluctuation, to a point where you can hardly hear anything.

I also have a LG Blu-ray (connected to TV via HDMI) and Samsung HDD Recorder (was connected directly to Onkyo via a cheap optical splitter but since taken out as part of my troubleshooting) outputting through the Onkyo without fault.

Can anyone offer any advice or troubleshooting tips to help work out what this could be please, it is making it very difficult to convince the Wife to stop watching Sky so I can cancel the subscription!!



Active Member
You didn't report if the Blu-ray connected directly to the TV and/or the HDD recorder connected directly to the Onkyo had the problem.
No ideas what it might be but my troubleshooting effort would include
1. temporarily replace the TV with a known good one.
2. connect TV to the Onkyo using analogue phono leads (if TV has suitable sockets).
3. ignore the Onkyo and test-listen to the TV speakers directly

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