[mythtv-users] Watch TV sends audio to PVR-350 audio-out, but recordings don't---any clues?

[f-myth-users at media.mit.edu]

    Date: Tue, 01 Nov 2005 15:16:07 -0500
    From: "Michael T. Dean" <mtdean at thirdcontact.com>

    f-myth-users at media.mit.edu wrote:

    >I have one more data point:  I took one of the recordings I made and
    >copied it to another machine.  (E.g., I just scp'ed one of the .nuv
    >files from /myth/tv elsewhere.)  mplayer plays the video just fine, and
    >-claims- that there's audio there (filter chain 48000Hz/2ch/16bit),
    >but I hear nothing.  Playing some other random .mov on the same
    >machine does give me sound.  So I'm beginning to think that there is
    >no sound actually laid down in the audio in the recording.
    >
    >The question is, why?  I would naively assume that using the same
    >tuner for both live TV and recordings should initialize it exactly the
    >same and lead to the same results, but this is clearly not happening
    >here.  So how do I even begin to debug this?  I see other people
    >who've complained about audio in recordings but not live, but my
    >situation is exactly reversed, and I don't have any good idea about
    >where to really begin as far as uncovering the cause.
    >  
    >
    Recording profiles?

    The LiveTV profile may be using different settings from the recording 
    profiles (Low Quality, Default, High Quality).

    Make sure you have 48KHz audio and that the volume is not muted/set to 
    zero in any of the profiles.

A good idea, but alas, I checked all four [default, live tv, high
quality, low quality] under the entry for
  mpeg-2 encoders (pvr-250, pvr-350) (myth-master-backend)
and they all say:

mpeg-2 hardware encoder
sampling: 48000 hz
type: layer ii
bitrate: 384kpbs
volume 90%