Realtek onboard SPDIF no sound output (for HDMI passthrough).

Forums › Home Theatre (including HTPC and EPG Collector) › Realtek onboard SPDIF no sound output (for HDMI passthrough).

Skolink

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#93039 11-Nov-2011 17:38

Just wondering if anyone else has the SPDIF output working on their motherboard with a Realtek chipset?
I have a Gigabyte GA-MA78GM-S2H with Realtek audio codec ALC889A.
I have the SPDIF output header plugged into my GeForce 9600GT which is in turned plugged in to my monitor via DVI and the TV via HDMI.

I know the graphics card SPDIF pass through -> DVI-HDMI -> TV work, because I used an older CD-ROM drive with SPDIF output and a Play button, and I heard the music on the TV while viewing the windows desktop.
I have checked the polarity of the motherboard SPDIF header with an LED.

I'm wondering if there should be a 'digital out' audio device also listed? I checked in BIOS and the only option is to enable or disable onboard audio.

I might resort to making an RCA-2pin header cable, which I would plug into the rear SPDIF output and feed it back in through a hole in the case to the graphics card.

hairy1

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#544344 11-Nov-2011 17:53

I had this same problem with my motherboard. It simply stopped working one day. I believe it was either a video driver update or sound card driver update from windows update. After hours of cursing and trying restores and driver roll backs a complete windows reinstall fixed it. Curses!

My views (except when I am looking out their windows) are not those of my employer.

Skolink

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#544390 11-Nov-2011 20:31

Thanks for the reply - your comment re OS installation reminded me that I hadn't tried Win7 since I discovered that I had the cable plugged in to SPDIF *in* on the mobo header.
Lo and behold there is an extra audio device! and it works!! Kinda weird it didn't show up before.

Strange that only the ticked sample rates work. Also with 48kHz unticked, rather than getting silence, I get the error box below when trying DTS Audio or Dolby Digital or WMA Tests.

Even worse if I select 48kHz here, and press Test, the TV looses video signal briefly!

But I'm stocked that the hardware is proven working. I'll persist with WinXP (for a while) since now I know it is just a driver/OS issue.

Skolink

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#544393 11-Nov-2011 20:35

Just realised why it probably doesn't work in WinXP. The "Output Sampling Rate" is fixed at 48kHz (see first post). Should my Samsung Series 5 LCD support 48kHz?

Skolink

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#544402 11-Nov-2011 20:52

Aaha! This also explains why in WinXP the TV often looses video signal - whenever windows makes a sound - at 48kHz! I had thought the cable or the TV was slightly faulty.

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#557820 14-Dec-2011 11:52

hairy1: I had this same problem with my motherboard. It simply stopped working one day. I believe it was either a video driver update or sound card driver update from windows update. After hours of cursing and trying restores and driver roll backs a complete windows reinstall fixed it. Curses!

It has now stopped working in Windows7. Now for 'hours of cursing and trying restores and driver roll backs'.
*Sigh*. I only use it occasionally, so there are about 2 weeks of updates that it could have been (incl Service Pack 1).

hairy1

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#557838 14-Dec-2011 12:20

If you get it sorted let me know. I tried the OEM video and sound drivers from the vendors and didn't find a fix except for full reinstall. Good luck.

My views (except when I am looking out their windows) are not those of my employer.

Skolink

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#566054 8-Jan-2012 13:01

Sorted (with Win7 that is). Turns out it was the TV, not Windows.

If, on the TV, you set the name of an HDMI input to "DVI PC' it disables the audio!! Samsung could have at least called it 'input type' rather than 'name', or put that setting on the audio settings menu. Idiots. I don't recall changing the name of the input, but I must have.

When my brother came over with his laptop, I discovered that it was only the HDMI input that the PC was plugged into that had no audio, so I thought it must be faulty. Of course I had tried swapping around the inputs with the TiVoHD back when I originally got the HDMI sound working.

It still doesn't explain why it wouldn't work in XP, or why 48kHz sample rate doesn't work, but at least I now have sound.

I would say to Samsung; KISS!