New Headset, solutions for optical for PC without it?

DHS Odium

So at PAX East I got a Tritton AX720 Headset. It's a 5.1 pair of headphones with a microphone built in. I would really like to use this thing.

It has a way to directly connect to my PC, through the pink mic port, and the green audio port. These are analog, and only give me stereo sound. Which is fine when I have my 2.1 sound system hooked up to the PC, but now that I have the means for 5.1 I'd like to try it out on some games.

The headset came with it's own amp, I imagine I'll get much better sound through the amp, even if it's only a stereo signal. The output choices when using the amp are limited - toslink/optical. There's a USB port but that's for the mic connection.

I have a Dell Inspiron 530 desktop, using onboard audio. There are six slots, the normal pink, green and blue, and then orange, black and gray. All are 1/8" jacks. I don't think any are those dual-use optical ports (like on my Macbook Pro 13"), and even if they were, I don't have the adapter.

So my question is this, how can I get optical on my computer? I've done research online, it's a Realtek ALC888 onboard chip, which supports S/PDIF, but it doesn't mean OEMs have to put it there, and I don't think Dell did. I took a quick look at the mobo and didn't see anything clearly labeled.

I have two spare sound cards, one is a Sound Blaster Live! Value, the other is a Turtle Beach Santa Cruz. The latter has a port titled "Versa" and sources online led me to believe this was a 1/8" jack capable of digital out. Problem is with my double-wide video-card, and wireless, I have 1 PCI slot free but it will block GPU fans. I might try to reorganize things to make room, but again, I don't have the adapter.

Either way it looks like I need to order something, whether it's an adapter for either 1/8" port, or the coax if I can find some solution with that. My videocard does have an HDMI port however, which I know carries digital sound - and the port does show up in the Sound options in Win 7 (x64). Is there some connector that has HDMI on one end, and digital audio on the other - using just the audio portion of the HDMI port? I've also seen USB adapters online that give a 1/8" toslink/optical/spdif jack, but I'm not sure how well they work.

Does anybody have any ideas?

Jeltz

Just an FYI in case you didn't know -- S/PDIF is usually stereo only. You can get 5.1 sound, but only if you are outputting an encoded DTS or Dolby Digital (DD) signal.

Lots of cheap sound cards come with S/PDIF outputs and these will happily produce a 2.0 stereo signal for your headset. If you are watching DVD movies, you can set the media player to "S/PDIF passthrough" mode, which will output the DD/DTS signal from the movie without decoding it first, and you'll get 5.1 sound. For games though, you'll only get 2.0 sound -- which is fine for a headset of course.

I can see from the specs that the AX 720 amp comes with a Dolby Headphone processor, so you may get some added benefits from using a DD 5.1 signal source. If that's your goal, you'll want a sound card with "Dolby Digital Live" technology, which encodes 5.1 sound from any source (including games) to a compressed DD 5.1 stream which can be outputted through S/PDIF.

I don't think there's an easy way to convert HDMI audio to S/PDIF. For one, the HDMI audio signal may be 5.1 or even 7.1 channels of uncompressed audio, while S/PDIF is limited to 2.0 channels in uncompressed mode. Secondly, the HDMI audio signal may be encrypted thanks to our friends in the MPAA.

You can get an expansion card for the SoundBlaster Live! with S/PDIF outputs, but that requires an additional free card slot and I don't think you can get DD Live on it. Don't know about the Santa Cruz.

To summarize:
If you're happy with normal digital stereo - get any cheapo PCI or USB sound card with S/PDIF. The USB adapter with Toslink that you mentioned would probably work fine.

It doesn't have to be a high end model as the sound quality of the digital signal won't be affected by any shortcomings the card may have.

If you want to fully utilize the Dolby Headphone processor in your amp, you need a card with S/PDIF and Dolby Digital Live. Check out the section on Wikipedia and google some of the cards mentioned there. Look for a USB model if you can't fit a PCI card in your computer. Here's what a quick search turned up for me:
PCI: Diamond Multimedia XtremeSound XS71DDL, Turtle Beach Montego DDL, ASUS Xonar D1
PCI Express: ASUS Xonar DX
USB: Sondigo Callisto Home Theatre Adapter, ASUS Xonar U1

Many PC soundcards output their optical S/PDIF signals through a 3.5 mm jack (like your Macbook I presume) in which case you'll need a 3.5mm-to-toslink cable, or a normal toslink cable plus an adapter.