[mythtv-users] SPDIF sound drop outs

[Peter Bennett (cats22)]

On 05/17/2013 08:17 AM, John Nissley wrote:
> On Tue, 2013-05-14 at 13:07 -0500, John Nissley wrote:
>
>> I am running Fedora 18 with the latest trunk version as of yesterday and
>> started noticing audio drop outs on my main frontend backend combo
>> server a few days ago.
>
> Just a data point: I run F18 also. I'm using the rpmfusion packages and
> I haven't updated for a while (don't want to touch the system until the
> Stanley Cup Playoffs are over). My SPDIF sound has worked fine. It may
> depend on what sound card you have.
>
> ------------------------------------------------------------------------------
>
>
> The sound is totally not working now so I have moved to the analog
> output.
> I am running Fedora 18 and I have been running this configuration for
> a few
> months without issue.  The only thing I know I did was update Fedora
> to the
> latest files.  I tried to go back to a previous kernel version but
> that did
> not help.  I am assuming this is hardware or operating system related but
> I just wanted to ask the list if there are any known issues in myth
> before I
> go through the troubleshooting tasks too deeply.  I only use this
> computer
> for mythtv so I will need to remove it from it's location to test if
> sound
> works with anything other than mythtv.  My analog sound ouptut works
> fine and
> it is just the SPDIF that is not working.  Maybe it is time to get off
> of the
> internal NVIDIA GF108 audio and pick up a sound blaster card or
> something.
>
>
What type of amplifier do you have? I have this problem with digital
audio going to a BOSE 123 system. I tried with both co-ax and optical
cables. The audio sometimes does not work at all, and I find by
switching the BOSE off and on again it starts working. Other times the
audio disappears for a time then comes back. Strangely it seems to
affect Live TV but not recordings.

Looking at the back of the BOSE I find that there are analog inputs as
well as digital inputs, all for "video 1", and no way of switching
between them. It seems the BOSE somehow tries to figure which is being
used, and I suspect that some tiny current fluctuation in the analog
circuit may be causing it to switch to analog mode. After my wife told
me she watched TV for an hour with no sound, I have switched to analog
inputs. Hopefully that will solve it.

My other frontend has digital optical audio going to an ONKYO receiver
and this works perfectly, the audio has never failed.

Peter