Optical Cable Question

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Don_S

Optical Cable Question
« on: 17 Mar 2018, 03:01 pm »
If I can see red reflected off the end of a cable does that mean there is a working signal?

I installed a new TV with an optical cable connected to my 2-channel amp with DAC.  I cannot get sound out of the TV.  My old TV worked fine in that configuration.  With the new installation the optical cable is severely bent because of the close fit to the wall.  I would have to take the TV off the wall to install a right-angle adapter.  Before I go through the effort, I would like to know if that would make any difference.  i.e. do I already have a signal or not?

The internal speakers on my LG OLED55C7P are almost useless.  As a temporary work-around I watch TV channels via a DVR with coax output to my amp.

Phil A

Re: Optical Cable Question
« Reply #1 on: 17 Mar 2018, 03:17 pm »
Have you checked the audio settings on the TV?

Phil A

Re: Optical Cable Question
« Reply #2 on: 17 Mar 2018, 03:17 pm »
Don't know if this is of any use but there are sites like this - https://www.doityourself.com/stry/5-common-optical-audio-cable-problems

Don_S

Re: Optical Cable Question
« Reply #3 on: 17 Mar 2018, 03:28 pm »
Thanks Phil.  Now I know I have a signal.  Figuring out the TV is ongoing.  It should be illegal to sell complicated equipment without a printed manual.  I hate scrolling through endless pages online and not being able to mark with a Post-it or highlighter.  I think it will be simpler to just send an email to LG tech support.  They do answer in about 24 hours.

John Casler

Re: Optical Cable Question
« Reply #4 on: 17 Mar 2018, 03:33 pm »
Is it possible to run the digital cable from the cable/sat box instead of the TV?

Don_S

Re: Optical Cable Question
« Reply #5 on: 17 Mar 2018, 03:40 pm »
Is it possible to run the digital cable from the cable/sat box instead of the TV?

John,  No box.  I am living FREE!  Antenna only.  :thumb:

I do not remember seeing coax analog outputs to use as an option. Very close fit to the wall so if I used them they would have to be the throw-away variety.  I need to open the manual I downloaded.

Phil A

Re: Optical Cable Question
« Reply #6 on: 17 Mar 2018, 03:45 pm »
John,  No box.  I am living FREE!  Antenna only.  :thumb:

I do not remember seeing coax analog outputs to use as an option. Very close fit to the wall so if I used them they would have to be the throw-away variety.  I need to open the manual I downloaded.

I took a quick look at the menu.  There is a button on the remote for settings and should be a way to navigate to audio settings.  Sometimes one has to change from internal to external speakers.

John Casler

Re: Optical Cable Question
« Reply #7 on: 17 Mar 2018, 03:48 pm »
Then chances are good, that your TV is either set to, or outputs "multichannel" digital and therefore the 2 channel DAC is not able to process.

As Phil suggests, you may be able to change that setting (if there is one) in the menu.

Don_S

Re: Optical Cable Question
« Reply #8 on: 17 Mar 2018, 04:02 pm »
Then chances are good, that your TV is either set to, or outputs "multichannel" digital and therefore the 2 channel DAC is not able to process.

As Phil suggests, you may be able to change that setting (if there is one) in the menu.

ARRRGH.  The curse of multi-channel. You and Phil may be on to something.  I was all over the TV setting menu trying to get it to work with my HT receiver which I was only using as a switching box before using the pre-outs to my 2-channel system. I did not see any place to select external vs internal or set to stereo. HT receiver had worked well with my old TV then started getting weird about connecting.  Did not work at all with my new TV even with multiple resets to factory settings on the receiver.

Both DVRs and the Bluray player work fine connected directly to the new TV via HDMI or through a simple HDMI switch box. So I know cables and all units work independently of the receiver.  At that point I put the stereo integrated with DAC back into use.

I sent an email to LG tech support.

srb

Re: Optical Cable Question
« Reply #9 on: 17 Mar 2018, 04:06 pm »
What model LG TV?

Edit: OLED55C7P

 :duh:

John Casler

Re: Optical Cable Question
« Reply #10 on: 17 Mar 2018, 04:18 pm »

Don_S

Re: Optical Cable Question
« Reply #11 on: 17 Mar 2018, 05:14 pm »
http://kr.eguide.lgappstv.com/manual/w17_mr/atsc/Apps/w3.5_mr_u02/u_enga/settings.html

See if this helps  Go to "SOUND OUT"

John,  The link was useful in me navigating my TV better.  TV was already set (not by me knowingly) to "internal speakers + optical".  There were also two other options that included optical.  None worked.  No mention of how many channels.  Can optical output be more than stereo?  That may not be the issue.

I suspect the DAC module in my integrated may not be working or a necessary part downstream of the DAC in the integrated is not working. I recently had repairs done to other parts. I checked the owner's manual and I am using the correct input selector.  Hey, I tried all of t hem anyway.

From the TV manual and TV screen settings.  No mention of coaxial outputs.

srb

Re: Optical Cable Question
« Reply #12 on: 17 Mar 2018, 05:56 pm »
When "Audio Out (Optical/HDMI ARC)" is selected, under Digital Sound Out settings you should be able to select Auto or PCM.  You want to select PCM.

Don_S

Re: Optical Cable Question
« Reply #13 on: 17 Mar 2018, 06:19 pm »
When "Audio Out (Optical/HDMI ARC)" is selected, under Digital Sound Out settings you should be able to select Auto or PCM.  You want to select PCM.

Steve,

It is set to PCM.  No other option available.

WC

Re: Optical Cable Question
« Reply #14 on: 17 Mar 2018, 07:00 pm »
Did you check your surround settings? You should be set to 2 channel. It looks like you should be getting PCM out, but the PCM audio could still be multichannel. It does not mention downmixing to 2 channel. Optical maxes out at 2 channel PCM. Multichannel PCM can be sent through HDMI.

Don_S

Re: Optical Cable Question
« Reply #15 on: 17 Mar 2018, 07:10 pm »
Did you check your surround settings? You should be set to 2 channel. It looks like you should be getting PCM out, but the PCM audio could still be multichannel. It does not mention downmixing to 2 channel. Optical maxes out at 2 channel PCM. Multichannel PCM can be sent through HDMI.

Surround is off.  In about a week I can swap in another integrated with optical in. That will tell me if it is a TV setting issue or the integrated optical input.

Thank you all for your suggestions and support.  You guys are great.

WGH

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Re: Optical Cable Question
« Reply #16 on: 17 Mar 2018, 08:10 pm »
Thinking about the other end of the connection, my DAC has 4 input settings: 2 coax and 2 optical. Check your DAC input switch?

Don_S

Re: Optical Cable Question
« Reply #17 on: 17 Mar 2018, 08:19 pm »
Thinking about the other end of the connection, my DAC has 4 input settings: 2 coax and 2 optical. Check your DAC input switch?

Done, done, and redone.  I even switched it off and back on. One of the first things I checked.

srb

Re: Optical Cable Question
« Reply #18 on: 17 Mar 2018, 09:35 pm »
A kinked or bent optic cable (particularly plastic fiber) will often let you see visible red light at the connector end (as can clear vinyl end protectors that some people neglect to take off), but often either can prevent signal lock.

Right-angle Toslink adapters and Toslink to Mini-Toslink adapters can also be problematic.

Don_S

Re: Optical Cable Question
« Reply #19 on: 17 Mar 2018, 11:35 pm »
A kinked or bent optic cable (particularly plastic fiber) will often let you see visible red light at the connector end (as can clear vinyl end protectors that some people neglect to take off), but often either can prevent signal lock.

Right-angle Toslink adapters and Toslink to Mini-Toslink adapters can also be problematic.

I was supposed to take off the end cover?   :duh:   :lol:

Steve,

I suspect you are correct. If the output does not work with a different amp I will try next week I will have to resort to a right-angle adapter and new cable. The cable I am using is plastic and severely bent.  Really dumb placement of the optical output on a skinny TV that is frequently mounted close to a wall.