[mythtv-users] PCI (or USB) soundcard that can passthrough SPDIF to surround sound amp

[Phil Bridges]

On Thu, Mar 20, 2008 at 11:03 PM, Kevin Kuphal <kkuphal at gmail.com> wrote:
>
>
> On Thu, Mar 20, 2008 at 9:58 PM, Phil Bridges <gravityhammer at gmail.com>
> wrote:
>
> >
> >
> >
> > On Thu, Mar 20, 2008 at 10:50 PM, Kevin Kuphal <kkuphal at gmail.com> wrote:
> > >
> > >
> > > On Thu, Mar 20, 2008 at 8:03 PM, Phil Bridges <gravityhammer at gmail.com>
> > > wrote:
> > >
> > > >
> > > >
> > > >
> > > > On Mon, Mar 10, 2008 at 10:00 AM, Kevin Kuphal <kkuphal at gmail.com>
> wrote:
> > > > >
> > > > >
> > > > > On Sun, Mar 9, 2008 at 12:54 PM, Rob Beard <rob at esdelle.co.uk>
> wrote:
> > > > >
> > > > > > Hi folks,
> > > > > >
> > > > > > I'm hoping someone might be able to advise me on an issue I have
> > > trying
> > > > > > to find a sound card.
> > > > > >
> > > > > > Basically I've upgraded my PC to a new Phenom 9600 with MSI K9A2
> > > > > > motherboard (the cheap version).  Now my old motherboard (an MSI
> P35
> > > > > > Neo2 with Pentium Dual Core E2160) had SPDIF output on the
> motherboard
> > > > > > which I was able to use an SPDIF header with to output AC3 and DTS
> > > audio
> > > > > > to my surround sound amp.
> > > > > >
> > > > > > The new board does have an SPDIF header on the board but it is
> only
> > > > > > 2-pin rather than a 3-pin header.  I have tried enabling the SPDIF
> > > > > > output in the Alsa mixer and sending the DVD audio to SPDIF using
> the
> > > > > > passthrough but I don't get anything (despite trying different
> > > > > > combinations of the 3 pins).
> > > > > >
> > > > > > So, after giving up on that I decided to look for a sound card
> that
> > > > > > would enable SPDIF passthrough.
> > > > > >
> > > > > > I've bought an external Sweex USB 5.1 Sound Card which has TOSLINK
> > > > > > in/out.  It's supposedly based on the CMedia CM106 chip.  This
> works
> > > in
> > > > > > Windows perfectly well as far as Windows sounds are sent over the
> > > > > > TOSLINK connection to my amp.  So far so good.
> > > > > >
> > > > > > I then reboot into Ubuntu 7.10 and although I can play sounds
> through
> > > > > > the analogue outputs on the card I can't get anything through the
> > > > > > TOSLINK connection, if I try SPDIF passthrough I get what sounds
> like
> > > > > > noise (a bit like if I was going to play a data CD in a CD
> player).
> > > > > >
> > > > > > I've also got a SoundBlaster Live 5.1 Digital (I think it's from
> an
> > > old
> > > > > > Dell) which I've tried connecting the digital out to my amp using
> a
> > > > > > 3.5mm to 2 x Phono cable and this doesn't seem to work either
> (I've
> > > > > > tried all sorts but from what I can tell it needs some specific
> > > commands
> > > > > > sending to the EMU chip?).  The analogue connection works but the
> > > > > > digital connection doesn't do anything.  I wasn't able to try this
> in
> > > > > > Windows as I can't seem to download a driver, just a driver update
> > > which
> > > > > > won't install!!!
> > > > > >
> > > > > > So I'm on the lookout for a new sound card which is supported by
> > > Ubuntu
> > > > > > 7.10 (or 8.04) AMD64.  I have an coax SPDIF to optical TOSLINK
> adaptor
> > > > > > (which does work - my amp has optical input) so either with
> optical
> > > > > > TOSLINK, coax SPDIF outputs or both would be ideal.
> > > > > >
> > > > > > Would something on the CMI8768+8CH chip (such as this:
> > > > > > http://www.ebuyer.com/product/106539) be suitable?
> > > > > >
> > > > > > If anyone has got any suggestions, or even knows how to get the
> SPDIF
> > > > > > output on a SB Live 5.1 Digital working then that would be ideal.
> > > > >
> > > > >
> > > > > I can *strongly* recommend two cards:
> > > > >
> > > > > TurtleBeach Riviera:
> > > > > http://www.newegg.com/Product/Product.aspx?Item=N82E16829118105
> > > > > AOpen Cobra AW870LP
> > > > >
> > > > > The first is a 5.1 with optical that *just works* out of the box
> with
> > > ALSA
> > > > > and passthrough (no crazy asoundrc files) and the second is a low
> > > profile
> > > > > card that works just as well in case you have a smaller case and are
> > > looking
> > > > > for that.  I cannot recommend the Riviera strongly enough for
> optical
> > > > > passthrough.
> > > > >
> > > > > Kevin
> > > >
> > > > Kevin -
> > > >
> > > > I also have one of the AOpen Cobra cards, and use the cmipci module.
> > > > I had this card working fine for AC3 and DTS files in a previous box.
> > > > I updated a frontend the other day to digital output (and 0.21) , and
> > > > put in this card.  I have digital audio working, but it's in stereo.
> > > > I have tried speaker-test, but I only get audio from the front left
> > > > and front right channels.  Is there any direction you can point me in
> > > > to get multi-channel working over the SPDIF?
> > > >
> > > >
> > > >
> > >
> > >  I never had to do much more than put in the card, set ALSA:default in
> the
> > > Myth config, make sure the IEC958 or whatever is unmuted in alsa-mixer
> and
> > > set Myth to AC3 passthrough.
> > >
> > > Kevin
> >
> > That's what I seem to remember, as well.  Argh.
> >
> >
> >
> >
>
> Try to upgrade/downgrade your ALSA drivers.  Maybe it's an issue with them.
> Also, in 0.21, check the upmix settings and be sure it is set to Stereo and
> Passive.  On mine, setting it to anything else was a disaster.
>
> Kevin

Thanks - I''l try that.

I re-emerged the alsa stuff (and, in the process, myth).  Now, it
looks like I'm getting the full AC3 track, but not DTS.