Question LOOKING FOR SOUND CARD With TRUE 7.1 SPDIF OPTICAL OUTPUT

[TRIBUNAL]

So, I have gone through 4 sound cards over the past month trying to find one that outputs TRUE UNFILTERED 7.1 surround sound through the optical SPDIF output. I would accept 5.1 if that's the only option? Most card advertise as 7.1 and 5.1 but when you install them the output is only Stereo through the SPDIF optical port. Apparently this has something to do with the quality of the port they use. I can't find the answer by reading product descriptions because apparently false advertising is legal now. I mean I am having to buy cards, install them, and test them just to find out they don't do what they say in their description, then return them... So I am looking to the experts for any help. If you don't have hands on experience dont bother replying because you can't go by what the companies say in the description. It's hard for me to believe that theres aren't any cards made that can do this, I was using a motherboard until recently that was 14 years old that had no problems doing 5.1... Thanks for the help and sorry for the aggravation.

 

[boju]

Dolby Digital Live encodes 5.1 on the fly but because optical is bandwidth constraint the maximum channels to be compressed to fit over the cable is 5.1. Has nothing to do with quality of optical port. Optical needs compression. Unfiltered or pcm, max 2.1 channels. It's why Hdmi is used for pcm 7.1 because Hdmi cable can carry the bandwidth.

See versions section and scroll down to Dolby Digital Live to get a description.
https://en.m.wikipedia.org/wiki/Dolby_Digital

Look for sound cards with Dolby Digital Live.

Example of one. There are others.

https://www.pccasegear.com/products/55091/creative-sound-blaster-z-se-pci-e-sound-card-and-dac

 

[TRIBUNAL]

Thank you for the help, Im in way over my head here, I read that part of wiki but... yea... The reasson I said quality is I read something about some manufactures using toslink and its limited so I assumed there was a better one..... So when you say optical has to be compressed, do you mean 5.1 and 7.1? Are you certain because I have used optical for 5.1 without an issue long ago. I would love to just use HDMI but this reciever and my last are limited to the quality of video resolution, i think 1080, so when I hook up my monitor to the reciever the resolution is trash. I wonder if they make a splitter that splits audio out of the hdmi so that I can keep the resolution... I dont know, I just wan this damn thing to work.
Heres an idea, what If I split the HDMI and sent one to the reciever and one to the monitor? that could work, sucks I wont be using optical but what can ya do...

 

[boju]

Only 5.1 encoded signal. Forget 7.1, if sound card advertises as such over digital spdif it's only virtual, pro logic etc.

In the past you probably had a dvd player which discs had compressed tracks on it already so avr just needed to decode it. That's what DDL does, encodes 5.1 (compresses) in realtime then the speaker system/avr decodes it as surround 5.1.

 

[boju]

Heres an idea, what If I split the HDMI and sent one to the reciever and one to the monitor? that could work, sucks I wont be using optical but what can ya do

Sorry im at work and kinda had to rush reading your last reply. Im on break. What gpu have you got? You can run separate cables, ie Displayport to Hdmi and use that for audio, or another Hdmi port from gpu if it had multiple. DP to Hdmi carries 7.1 surround audio no problem.