SPDIF from Realtek ALC269 audio chip (netbook)

[Rodeodave]

First off, the lenovo ideapad s10e is a great device for modding, not only because lenovo has training-videos online showing how to take the whole thing apart (plus a service manual). It could also be a really nice source for audio:

The audio chip it (and i think also the EEE PC) uses is the Realtek ALC269. General description here:

http://www.realtek.com.tw/products/p...n=4&ProdID=166

It seems like the chip has two S/PDIF outputs (quote:SPDIF-OUT support 16/20/24-bit format and 32/44.1/48/88.2/96/192kHz rate).
You can also find a datasheet and a reference design when you scroll down to the bottom. The reference design shows a coaxial (75R) and optical spdif-output.

The actual chip on the motherboard has nothing connected to the two spdif-pins, it seems, unless there are vias underneath the chip. (see picture)
The pins I'm referring to are 47 and 48, bottom left, lowest two in the vertical row.

I think there'd be enough space to fit a DAC plus a little headphone amp even inside the laptop's case (one could get +5V and +12V from the motherboard), the other spdif could be routed outside for an external dac.

So, my questions are:

Do you think that one needs to enable the spdif outputs? Realtek offers a "generic" driver for their audio chips, maybe it'd be enough to install these and one 'd get and option to enable them...

Does anyone have experience with this chip or a similar one, also not specifically mounted inside a s10e?

Maybe I'll find the time to stick a probe to the pins and just see if something comes up on the scope...greets, Dave

[wwenze]

"one could be used to connect a PC to high-quality consumer electronic products such as digital decoders and speakers, the other could provide a dedicated digital output to a HDMI transmitter"

And not all notebooks have SPDIF-out or HDMI. So you can be sure that it isn't connected on those that don't. They'd be connected on laptops that use them.

But... from my experience with Realtek onboards, I have to say that one can look elsewhere for good audio source. I don't understand how digital signals can sound different though.

Oh, my bro's laptop uses ALC268 i think, with SPDIF-out via shared 3.5mm optical minijack, verified to work. I'm using ALC888S SPDIF-out (also mini-optical) to my DAC. Both Acer laptops. So I'd say spend less time voiding warranty and get a notebook with SPDIF-out.

[BrianDonegan]

Do you think that one needs to enable the spdif outputs? Realtek offers a "generic" driver for their audio chips, maybe it'd be enough to install these and one 'd get and option to enable them...

I guess trying to get the S/PDIF outputs recognized and enabled through the drivers would be a good place to start to see if it is a doable project, just to be sure it's possible.

Assuming you can, soldering a lead on Pin 48 then through a small resistor to limit current output and you should be good to go. Mounting an external jack would be pretty messy.

[Rodeodave]

update:

I found a lenovo laptop, the y450, with the very same audio chipset (alc269) and it has hdmi and optical out.

specs here:

http://reviews.cnet.com/laptops/leno...-33631821.html

I'll try to install the audio-drivers from the y450 on my s10e and see what happens...

[Rodeodave]

Well, I tired both drivers, the 'generic' one from Realtek and the one supplied with the Y450, and unfortunately no digital output is showing up in the audio manager

Does anyone have another idea how to get this to work?

If not I'll maybe go with an internal USB DAC, still have some PCM2706 somewhere...

[phofman]

Originally Posted by Rodeodave

Well, I tired both drivers, the 'generic' one from Realtek and the one supplied with the Y450, and unfortunately no digital output is showing up in the audio manager

Does anyone have another idea how to get this to work?

If not I'll maybe go with an internal USB DAC, still have some PCM2706 somewhere...

Your HDA codec (ALC269) supports spdif output, but it has to be enabled and the PCM data redirected to its internal spdif transmitter. Generally the codec must be configured for this to happen which is the job of the driver. If your driver does not do that (highly likely, the notebook has no official SPDIF output), you may try to reconfigure the driver (some may offer some config ini files). Having the same HDA codec is no guarantee that drivers for different notebooks will work since each manufacturer uses a different setup of the Intel HDA controller and HDA codec (often even close models by the same manufacturer have a different setup).

The reconfiguration is feasible in linux where the HDA driver exports its configuration to user space (sysfs) and the developers have provided a rudimentary configuration utility.