[mythtv-users] Chaintech 7NIF2 Sound Problems

Dalen Kruse blacklion at blacklion.org
Wed Mar 31 09:48:04 EST 2004

Hmmm.....  A little strange that two people have this working fine with
full-duplex.  I tried the NVIDIA OSS drivers and ALSA drivers.  With both
drivers, I had my mythbackend giving me a message that my sound hardware
wasn't reporting full-duplex capability.  I'm not sure if it's a hardware
or driver issue.

Also, I've noticed on this list that there are two versions of this board.
 The "older" board with SPDIF headers on the board and a "newer" board
without the headers.  I have the newer board.  My board also does not use
the nForce2 MCP-T chipset for sound.  It has a separate CMedia chipset. 
Perhaps the older boards are using the MCP-T which has full-duplex
capability?????  I don't know.

What I do know is that my life has been much more enjoyable since I
disabled the on-board sound and started using a dedicated sound card. 

> I've got a 7NIF2 running full-duplex just fine.  I've got a TV Wonder VE
> in a custom (gutted component cd player) case with the audio output
> going into the line-input of the motherboard.  Volume control works
> perfectly.  The only problem I've had with the sound is a strange
> buzzing (live tv and recordings) that went away when I bumped up my mp3
> frequency to 48khz.  Now everything is working wonderfully in live tv,
> recordings, dvds, etc.
> Matt
>> This was my fear.  I've built this into a half height Case, and I'm
>> not having any luck finding a half height sound card.  so I'ts buy a
>> new case or buy a new card.  Thanks
>> Ben
>> Dalen Kruse wrote:
>> >I was having the same problems with that board.  What I found out
> (someone
>> >correct me if I'm wrong) is that the on-board sound does not support
>> full-duplex.  If your experience is like mine, it sounds great when
>> playing a sound file through XMMS or watching TV with XawTV, but
>> horrible when watching TV with Myth.
>> >
>> >There are three solutions to this problem.
>> >
>> >1. Make this machine a dedicated backend that only does the
>> recording. That way you don't need full-duplex sound.  The downside
>> is that you'll need another machine for a dedicated frontend.  Most
>> expensive option.
>> >
>> >2. Dump the bttv card and buy yourself a PVR-250 or -350.  The sound
>> is encoded directly into the MPEG-2 stream, so your on-board sound
>> doesn't need to do the recording.  Second most expensive option.
>> >
>> >3. You can do what I did.  Disable the on-board sound in your BIOS
>> and find yourself a separate full-duplex sound card.  I'm currently
>> using a SoundBlaster Live 5.1 PCI card and it sounds great.
>> Depending on where you buy it, this card can run you $35 to $50.  If
>> you do get a separate sound card, MAKE SURE it will do full-duplex.
>> BTW, stay away from CMedia chipsets.  The older ones (i.e. 8739)
>> supported full duplex, but cut the sampling rate in half so you still
>> had terrible sound.
>> >
>> >Hope this helps.  This was my most frustrating part of building my
>> Myth box.  It's running rock solid now and I'm very happy with the
>> results.
>> >
>> >--B
>> >
>> >
>> >
>> >
>> >
>> >>I know this isn't the alsa mailing list, but I know many people use
>> this
>> >> board in their Myth Boxes, so I thought I'd ask.  Is anyone using
>> the
>> >>onboard audio for sound capture.  I have this board with a bttv
>> card, and I'm getting horrible audio.  When I aplay /dev/dsp the
>> audio is really crackly, and it plays at a set volume.  Changing the
>> master volume doesn't affect the sound output at all.  Playing other
>> sounds works  fine.  Xawtv sounds fine and the volume controls work.
>>  It's only
>> >> the playing the dsp that doesn't work.
>> >>
>> >>The sound from the bttv card runs into the cdaudio jack on the MB,
>> and I'm using alsa 1.03 and the latest Nforce drives on Mandrake
>> 9.2.
>> >>
>> >>Has any one had similar problems?
>> >>
>> >>Thanks
>> >>Ben
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>> >>
>> >>
>> >
>> >
>> >
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>> >
>> >
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