My odyssey to 5.1 digital surround sound (1 Viewer)

[milagroso]

Hello all,

I wanted to report from my odyssey and hope that it helps someone.

The target: Enjoy digital 5.1 surround sound.

Initial situation: New MoBo ASUS M4A78 Pro (replacing older broken Mobo), AVR Onkyo SR 606. Both are separated by a thick wall but connected via a ductwork completely filled with one thick 5m HDMI cable and one old fashioned audio stereo cable.

The problem: The ASUS mobo comes with an optical SPDIF out, but with no coaxial one. In my previous configuration I connected the coaxial out with the AVR and that worked perfectly. It's impossible for me to pass an optical cable through the ductwork.

Initial fallback: Use analog out. Resulting in surround 'only' on ProLogic level. Not satisfactory.

Trial 1: Get the SPDIF bracket from ASUS referenced in the manual. No chance. This product is available nowhere for months, neither in german computter shops nor on ebay. ASUS did either not respond or did respond in an unqualified way regarding availability of the bracket.

Trial 2: Use the HDMI-cable for the transmission of the sound. After 6-8 weeks I gave it up. For some reason the sound processor of the ATI 3200 onboard graphic chip required for this could not be extablished in a stable manner in WinXP. I tried different drivers in different versions from ATI and from Realtek, turned off the VIA onboard chip in the BIOS, googled and tried and tried and tried...

Trial 3 and solution: I soldered an electrical SPDIF interface in a DIY manner (1h). I took this simple schematics from here:

         100nF
  TTL ----||-----330ohm--+--------- coax S/PDIF signal out
  in                     |
                      100ohm
                         |
 Ground -----------------+--------- coax signal ground

After many years of abstinence the soldering was quite challenging to me... I connected my circuit to the corrsponding pins of the MoBo and the AVR and voila: With some luck I made no big mistake and now I can receive the digital sound of all those AC3 and DTS coded movies on my AVR.

Some lessons learned:

• Always make backups before starting experiments. I use a second partition on a second disk which gets a 1:1 copy of my current live partition. In the BIOS I switch between these two disks. In some cases my experiments left me with no sound device at all, which my WAF would not have accepted.
• Always try to understand the basics and architecture of the affected components. I learned a lot about sound devices, drivers, PnP - but as it seems not enough to make my HDMI cable transport the sound. It's easier to find tips (the 'how') in the internet than solid basics (the 'why').

regards from Stuttgart

 

[WhiteNinja]

Hi,

you could buy a spdif bracket on ebay: ASUS Motherboard SPDIF_Out Coaxial Audio Bracket Cable bei eBay.de: Sound Cards (endet 28.01.10 12:35:00 MEZ)

or you could use a converter like this: Optisch Koaxial Wandler inkl. Netzteil - Toslink in>: Amazon.de: Elektronik

Greetings,
WhiteNinja

 

[milagroso]

AW: My odyssey to 5.1 digital surround sound

you could buy a spdif bracket on ebay

Hello WhiteNinja,
You're right. However these offers were rare (I remember scanning ebay during a month or so) and then they cost the same or even more than the new bracket from ASUS.

or you could use a converter like this: Optisch Koaxial Wandler inkl. Netzteil - Toslink in>: Amazon.de: Elektronik

In fact this was my planned fallback solution, should my DIY not work.

Have a good time...