Realtek On Board HD Audio - digtal out.

[davejberry]

Have a home built XP pc with the above soundcard (integrated) on a Gigabyte main board. I already stream lossless to the lounge via twonky media and a wdtvlive player. I also want to improve the quality of the music when I am working on the computer.

The Mobo has a digital out (coax & toslink) and can be activated in the realtek sound manager software. My question is, does this digital out by-pass all the windows mixer rubbish so i can connect to external DAC, amp and for better SQ or do i have to do something else to avoid windows' interference. If I have to do something else, can anyone enlighten me as I'm old and don't understand much about software / kernel streaming / ASIO ?????????

 

[davydmx]

Hey there,

yes, ASIO/kernel streaming/WASAPI (one of these) will be required to bypass windows mixer, but it means using media software other than iTunes, as iTunes doesn't work with any of these 'plug-ins'.(incidently, iTunes doesn't need plug-ins when used on Mac, as that's bit-perfect 'out the box')

I'd recommend Foobar, but others, such as J.River Media Center, can also utilise WASAPI, etc.

 

[Anonymous]

One option is to set up the system that you can also stream to/in the office - controlled by the computer. Can't you access twonky from there?

On the other hand I had no problems with XP and kmixer, as long as you make sure that system sounds are off, volume at 100% etc.

 

[Anonymous]

Dave,

Not sure which one of the Realtek chipsets you have on board (probably one of the newer ALC88x types).

I have the ALC888 on board with the SPDIF input/ouput selector via the Realtek HD control panel.

In theory, the ASIO4ALL driver should work with the Realteks and they do support Kernel Streaming and WASAPI so you can bypass the Windows Mixer.

However there is one small caveat and that is the driver. I have done several tests and so far i cannot get it to do unmolested 2 channel PCM via the SPDIF, although AC3/DTS passthru works. This means that even when Kernel Streaming in Windows XP, I can still here the speaker test noises coming through my external dac via SPDIF output. The driver seems to always send a front speaker two channel "DSP sampled mix" via the SPDIF out. The driver also accepts 32bit float PCM via kernel streaming and I can still here audio on the Quad 99CDP2 which accepts up to 24bit, so there is definitely re-sampling going on in the driver somewhere which is a shame.

It not a big problem for listening to CD sourced MP3 material as i also have an older £20 CMedia 8768+ PCI card that will do bit perfect SPDIF in/out with Drogberts Homebrew Drivers, however this is only 16bit, so I am currently exploring a better 24bit solution.

 

[Anonymous]

After having done some more stringent tests with an external decoder over the last couple of days, I can now be sure that Realtek ALC888 (and I would imagine most other ALC88x variants) are capable of bit perfect ouput via their SPDIF.

Providing the sample rate of the chip matches the PCM output, all effects switched off, and as a precaution all other mixer inputs muted, I was able to kernel stream in XP a 16bit 5.1 AC3 file disguised as a 2 channel WAV file to another computer with SPDIF capture facility.

Using GraphEdit on the capture PC I was able to connect the SPDIF in capture pin to AC3 Filter which correctly identified the hidden AC3 track in the stream.

As soon as I started messing about with effects or speaker testing (had to enable the wave slider to hear this) on the Realtek control panel on the other PC, the stream reverted to two channels of noise in AC3 Filter, as soon as everything in the control panel was reset, AC3 Filter reported a 5.1 channel which means the chip can send untouched PCM albeit at a manually selected sample rate.