SPDIF not working....

Your motherboard seems perfectly suited to pair with your Panasonic amplifier.

My first question would be, what audio are you expecting to be playing in 5.1? Movies and some television programs you may play on the computer are about the only content that will be pre-encoded to actually play with more than 2 channels of sound. Games, while they support surround, require real-time encoding be in place on the computer to translate the game's output to a surround signal which is then sent to your external audio equipment. In your case, you should be using DTS-Connect, as
that is what both your motherboard and amplifier support.

When attempting to use the SPDIF output of the motherboard, have you first configured the computer not to use the HDMI audio device?

I would stop worrying about your computer's BIOS in relation to your sound. It really isn't related to what you're trying to do.

One issue I believe you are facing is, your HDMI and SPDIF connector on your motherboard are two distinctly separate audio devices. When your computer outputs audio, it has to choose one of those two audio devices to send the sound to. If you are hearing your audio currently through your HDMI connected screen, you will not be getting the same sound through your SPDIF, as the computer is not sending the sound there. Duplicating the sound, or sending the sound to every output available at the same time, is not an option.

For your SPDIF to be active, you have to set that as your default audio device or alternatively, specify in each program (not always possible) to output to your SPDIF. Also, sometimes you must specify in Windows for that playback device that it is to output digital sound.

To address your concern that your Dolby light on your Panasonic unit doesn't light when using SPDIF from your computer - It shouldn't. SPDIF and Dolby are two different things. SPDIF is only the connection type. Dolby is an encoding type, so unless you are sending Dolby encoded audio, or having your Panasonic up-mix or convert to Dolby, you should be getting standard stereo. According to Asus's specifications page for your board, they do not provide Dolby support, so, that's not really an option, but that's also not a major concern. Asus has chosen to provide support with your motherboard for the DTS Connect format instead, which your Panasonic amplifier should handle fine. Instead of Dolby lighting up, you should see the letters DTS, when it is decoding DTS encoded audio content.

For your DTS to work correctly, you will need to ensure you have the correct, DTS enabled driver from Asus, which should provide an option for DTS Connect output via your SPDIF connection. Once you have that in place, have the SPDIF designated as the default audio device for Windows to be outputting sound to, and have ensured that it is sending digital audio, you should be set for playing games in surround.

Concerning your Sky box you use for TV working fine, that makes sense. TV signals have their audio already encoded into Dolby or DTS, so as long as the amplifier is seeing the audio, it will decode it, as it has the encoded audio data. Since computers do not automatically encode to Dolby or DTS by default, you won't get that feature unless you track it down and figure out how to turn it on. The default audio format for SPDIF or other forms of digital audio is simple stereo. Encoding Dolby or DTS is the method used to overcome this for multi-channel sound. Encoding generally carries a licensing cost, which manufacturers obviously don't want to pay needlessly, so often times you don't even have the option available.

On the previous PC that had the SPDIF working correctly, it's very likely somebody had previously configured it for SPDIF output, or had done so during any initial setup for you.

One thing to note is that, sometimes when you install graphics drivers or connect a new HDMI display device, the default audio device may switch from analog or the motherboard's SPDIF to the graphic card's HDMI audio device instead. Make sure you check in the Windows Sound Devices Control Panel section to determine where Windows is trying to route your sound.

Your HDMI audio options should actually be related to your graphics device in your computer. Oddly as it may seem at first, HDMI requires that the audio have a protected path so no nasty pirates can tap into it and make duplicates. While this may sound like a good idea on the surface, it's really only caused headaches for the users who just want to use it normally over the years. To provide the protected audio path, graphic device manufacturers have had to build audio devices into their graphics devices, which often results in pointlessly replicated equipment inside computers. Furthermore, you run into the problem that, your computer is usually only going to ever send sound to a single output device, so it causes confusion when a person doesn't realize the HDMI audio is actually a second audio device, not simply a different path for your primary audio device to pick from. Having been through your Sound Control Panel options, you've probably seen what I'm talking about - multiple devices to pick from.

Something you might try with your SPDIF output is going to the Supported Formats and testing each output type. There should be options for Dolby, DTS, and probably even Microsoft WMA. These tests are pre-encoded, so selecting one of those options and pressing the test button allow you to at least determine if your computer will pass pre-encoded sound through the device you're testing.

I appreciate your frustration with this project. Purchasing a sound card is not really the solution, as this is a configuration issue. After adding the sound card, you will be presented with the situation of having to correctly configure it for the output you are trying to achieve.

If I may ask, what Playback Devices are available to you under your Sound Control Panel configuration options? It may be beneficial for the time being to right mouse-click the device(s) we're not wanting to use and only leave enabled the one single device we do want to use. This can prevent the chances of sound being sent to the wrong device.

Whether you have your SPDIF connection attached or not should in no way determine settings available to you. While jack detection is sometimes possible with older analog connections, an SPDIF output has no such ability, therefore the computer has no way of knowing whether or not you're SPDIF connector has anything plugged into it.

Well, so far so good. We've established the correct sound device to be using under Windows and it is configured now at least for basic output. As for proper multi-channel support, we can continue to work on that.

It may help to reiterate what happens in a surround or multi-channel setup.

Digital audio over SPDIF is only ever two channel. It was designed quite a long time ago, when movie theaters were still looking into multi-channel sound for themselves. Imagining we would have this kind luxury in our homes and computers was just a distant forethought for dreamers. So, for now, imagine all digital audio output solutions from a computer as stereo. Once you have gotten that far, the audio solution in your computer is for the most part, done with it's job.

How then, do we have nicer, multi-channel setups now? Well, when multi-channel became something that could be consumed outside of the theater, smart people figured out that if they encode extra information into the audio streams available over the basic 2-channel setup, they could extract or decode this information on the other end. They were still living within the limits of their 2-channel audio distribution model, but now they had a method of encoding many more audio channels into those two, simple stereo channels.

For this to work, you have to have audio that is encoded. The two most common methods I'm familiar with are Dolby and DTS. They essentially do the same thing, so whether you're stuck with one or the other is hardly reason to concern. Also, the technical specs of each, while not identical, are not different enough to make a major impact either. Let the audio snobs say otherwise (most source material that people enjoy will be of such quality, the transport mechanism is hardly any influence [besides, at which particular bit-rate do cat meme videos truly become bearable!])

There really are two scenarios most people deal with, concerning the encoding of audio. Pre-encoded or live encoding. When you watch a TV show, DVD, Blu-ray, etc., the audio you receive is of the pre-encoded type, so it has all of the multi-channel sound already in it in such a way, as soon as the pre-encoded audio is sent correctly through your 2-channel SPDIF or coaxial digital connection to your receiver, voila, it just works. It's recognized, decoded, and sent to the correctly corresponding speaker.

In the case of computer video games, however, this really doesn't work. What we want is correct, positional audio, that supports a multi-channel speaker setup, but you can't do this with pre-encoded audio. Instead, the audio is generated by the game, with it's 3D position information, and then it goes to an encoder to prepare it for the final transport over the 2-channel digital audio output. Both Dolby and DTS have live encoders, and go by the names Dolby Digital Live and DTS Connect respectively. These are technologies that have to be licensed, otherwise they would likely be quite common. Because of this, instead of every game manufacturer or publisher licensing this technology, they leave it up to the consumer to instead acquire a single license, and then just apply it to all sound that is headed out of the computer. So, while your games may be generating the 3D audio, they don't encode it, so at best over digital, a game will stick you with 2-channel sound. What is needed is the encoder to act as mediator between the game and audio device in the computer, and encode the 3D positional sound for you.

That is where we're at. We need to figure out how to activate the live encoding on your system.

Back in the Properties, Sound Formats tab of your Realtek Digital Output sound device, you should test whether or not you are getting proper transport and decoding of DTS and Dolby by first clicking the DTS Audio option and clicking Test. Since this test is already encoded for you, it will help determine whether your receiver is actually decoding the signal properly. Selecting DTS Audio and clicking Test should cause your receiver's DTS light to come on, just as selecting Dolby Digital and clicking test should light the Dolby symbol on your receiver, provided it supports those formats.

If that's the case, the next thing to try would be, if you have available, DVD playback of a movie with 5.1 sound. In your DVD playback software, configure it to use SPDIF output for audio. This causes the player not to decode any audio but to instead just send the audio stream to your output, so your receiver can decode it. Playback of a movie with 5.1 audio should result in the Dolby or DTS logo on your receiver lighting up. Don't of course expect the menus or special features to be encoded. Usually only the main movie has the multi-channel encoded audio.

Hopefully you can perform a test or two and see your receiver kick into DTS or Dolby...

If your Panasonic unit supports both DTS and Dolby, might as well leave those checked.

Glad things are sorted and working. Nothing beats some good sound when watching movies and playing games. Makes the trouble worth while. Oh, and having a Panasonic unit myself, if you happen to have a selector button on the front labelled "DSP Sound Mode" or similar, this can force the receiver into Stereo mode instead of Surround, regardless of what the lights might be indicating. If you find your lights don't match what you're hearing, make sure the display doesn't say "Stereo" in eensie sized lettering instead of "Surround".

Here's a handy, Dolby Digital encoded test file that should work fine in Windows Media Player, if you find yourself in need to test whether your speakers are outputting correctly. http://www.tfm.ro/ac3/download/test_ac3.rar