In article <3f435c65$(E-Mail Removed)>, "Dave Catchpole"
<(E-Mail Removed)> wrote:
> "Sanjay Chakravarty" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > I bought this A7N266-VM mobo (I know its a dinosaur, but my kid is happy
> > playing games on it), and notice that it supports SPDIF on a 2-pin
> > connector. From what I understand, this needs to be converted to coaxial
> in
> > order to drive my AV Receiver system, right? Does anyone know the circuit
> to
> > do that?
> >
> > Regards
> > Sanjay
> >
>
> It's on an optional riser board.. an Asus dealer should be able to supply
> the necessary part...
>
> HTH
>
> Dave
Comparing the picture in the manual to this web page:
http://www.asus.com.tw/mb/mb_accessories.htm
it looks like the left most "SPDIF Out" module.
This page at Newegg has a couple of pictures on the "See it" link - they
are slightly different but presumably functionally identical.
http://www.newegg.com/app/viewproduc...82E16813131204
I don't think you can use the SPDIF signal directly from the motherboard,
because the signal has enough amplitude to drive the optical module.
There are several surface mount components near the coax jack of the
adapter, and their job is to "tame" the signal to a level suitable for
your receiver. According to one web page, around 0.5V peak to peak is
driven down the cable.
Cable: 75ohm +/-5% (l<10m) or 75ohm +/-35% (l>10m)
* Line driver:
* Zout: 75ohm +/-20% (100kHz .. 6Mhz)
* Vout: 0.4Vpp .. 0.6Vpp, <0.05Vdc (75ohm terminated)
* Line receiver:
* Zin: 75ohm +/-5%
* Vin: 0.2Vpp .. 0.6Vpp
HTH,
Paul