Using the right cable for spdif?


Pete Delaney

Please would someone clarify my thoughts on what's wrong here.

I am trying to output 5.1 digital from the spdif on my audigy2 souncard to the dvd digital input on my Sony strdb 930. I found a cable which starts with a 3.5mm jack and splits into 2 phono, I then found a 2 phono cable adapter which takes both phonos into a single phono. This effectively allowed me to connect from a 3.5mm spdif jack output on the pc into single phono digital input on my amp.

Well there's no sound going down the line from pc to amp when I play a dvd on the pc, part of me is saying I'm not blo*dy surprised!:blush:

The reason I'm messing is because I want to try home cinema on my Z1. However, I'm not willing to splash out on PC cable to transmit the picture to the Z1 until I know that I can also get digital output into my amp from the pc.

I don't fully understand what you can and can't use (in terms of types of cable and connectors) to transfer a digital signal into the amp so that I can have DD/DTS effectively coming from my pc and being decoded by the amp.

Would someone point me in the right direction please.....:blush:

All help greatly appreciated as frustration is setting in!
I am using exactly the same as you except for a slight alteration.

I have a 3.5mm jack to two phono cable, but instead of then getting an adaptor to take the two phonos to one, I just plug one of the phonos into the amp.

Works perfectly DD, DTS 6.1 ex es etc etc.

Its trial and error to get the right phono to start with but you only have a choice of two!

Although I have not yet been able to get any PC sounds through the amp like game sounds, music etc but thats a different story. Only DVD.

If the Audigy2 is the same as the Audigy1 that I have there's a setting in the SurroundMixer you need to set correctly so that it passes DD/DTS out of the SPD/IF un-decoded.
I've found the spdif box and checked it for output but still no joy.....:(
Theres also an audio box to check on my windvd software, checking it supposedly alows spdif output but I still get nothing...


You Know when you get really really frustrated and it reall hisses you off? WELL I'M IN THAT PLACE RIGHT NOW...

Damn pc/soundcard/cable:mad: :mad:

If my dvd player had arrived I probably wouldn't have started doing this ..... but no I ring up because it should arrive after 5 days and 10 have gone be told...oh it's sony there not making the 730 anymore and we are waiting for 40 units to come in....perhaps you'll get the player in a week or 2......I could have screamed they did not tell me it was not in stock and my credit card was debited over a week ago!!:mad: :mad:

In case your wondering I'm not pleased!!!

Going to get a beer.......MUST calm down, think calm thoughts....:(
There's also a checkbox marked "AC-3 Decode" in the "Settings" dialog of the "Speakers" section of the mixer. That needs to be Off.
Thanks KraGorn,

The ac3 unchecks itself automatically when I select spdif so it's not that.
I'm out of ideas. :( My Audigy 1 has a 'proper' phono coax SPD/IF so I've no experience using a 3.5mm jack. I assume it's a mono jack, since the SPD/IF only needs one 'live' wire .. I'm unclear as to why you're connecting two leads .. if it's because the 3.5mm jack is a stereo connection then I don't understand why an SPD/IF needs two 'live' wires. :rolleyes:
Not to wory KraGorn,

I've run out of steam myself, I don't think I'm going to solve this one quickly....
....thank you for your help though:)

I think I'll try again tomorrow, perhaps inspiration and a new day may help!

Now that I've calmed down I think I'll chill out with a 'cold one',
thank god for cold lager!:D :D :D

EDIT: Yes the spdif is mono, read the whole thread and you'll see how I arrived in this mess!
Thanks again KraGorn, your suggestions were appreciated:)

The best way to go is with a phono socket to 3.5mm mono plug adapter and then a digital audio coaxial cable (phono-phono) from the adapter to the amp.

What you have tried should work but you may have caused enough of an impedance mismatch for it not to.

I can supply all the parts you need for this but are you sure the SPDIF is a mono socket, I have supplied a lot of 3 way 3.5mm jack cables for people with sound card SPDIF. I don't know the pinout of the audigy myself?

I'm sending you a pm (private message) with regards to this.
I think the problem could be the fact you are using a stereo jack at the board end, I do believe the Audigy SB cards output jacks are mono configeration, it could just be the stereo jack is wired wierd....oooo that was odd! and not quite right as far as dimensions go on the pin, if its a cheap plug?
When I used a SB4.1 card in my HTPC I used a mono 3.5 to phono adapter, into 75ohm cable to the AMP, worked a treat, just as TVCables has suggested above.

Best regards David
I'm guessing my cable is wrong so I've ordered some stuff from Andy and some stuff from keene electronics. Infact everything I need for HCPC viewing should arrive tomorrow/friday. The fact that my jack feeds 2 audio cable suggests stereo, I think you are right Dave.;)


Cable arrived from Andy today (5m 75Ohm digital phono/Cheers Andy). I discovered I already had 2 mono spdif adapters:blush: they were in a bag of connectors I had bought from Argos ages ago:blush: :clown:


HCPC in time for the weekend as my monitor cable should arrive tomorrow

:smoke: :smoke:

Off to go and do a happy little Irish Jig:D :D :D
Glad that fixed it Pete, you do have to be careful with impedance for digital audio, also if the cable doesn't have enough bandwidth you will start to lose the edges of the signal and eventually it will just not work.....

Regards to all,

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