Best way to decode DD 5.1/ DTS without receiver?

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NerevarReborn

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Jul 10, 2012
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Hey!

I've been searching the internets for answers to my questions for some time now, but all my findings have been very inconclusive.. Either it seems I'm trying to do something that no-one else in the world has ever wanted to do before, which would be pretty weird, considering what it is, or the answer must be so obviously simple that I'm completely missing something. That would also be strange in this case, since I've been into HiFi and home-cinema audio for over ten years, and like the technical side of it. I'm also good at my PC-stuff, been building my own for many years, and am just as interested in that.

Anyhow, firstly, what I'm trying to do, and I can explain why I want to do this in just this way later:

I want to take a digital surround audio stream, either Dolby Digital or DTS (needs to support both, and work with the newer HD-formats) from for example an Xbox or TV-box. Not sure here if I need PCM, or only AC3? This over an optical cable. Into either some dedicated decoder, or into an optical input on my PC. Decode the signal, and get the surround outputted via preferably RCA connectors, but 3,5 mm jacks would also work. Then into my analogue 5.1 input on my amp, and onto my speakers. So:

DD/DTS - Optical - PC/Decoder - Analogue 5.1 RCA or 3,5 mm - Amp - Speakers.

Now, I have an optical input on my Creative Sound Blaster Z, but that only supports stereo audio, and can't decode DD/DTS. Seems a few older Sound Blasters and a few other sound cards may support decoding, but I still haven't seen any solid answers as to what will work, and without loads of tweaking with different software and stuff, without severe lag in the audio-stream. Dedicated home cinema surround-processors are awesome, and do exactly what I need, but they are very expensive, since they are almost always high-end, and many times cost as much or more than the flagship surround-receivers... Also, they have limits, they do get old. And computers are a lot more flexible and easier to adapt to new technologies, be it a new connector or audio format. So I'd rather invest in my PC for this as well.

If you need to know why I have to have analogue 5.1, it's pretty simple, my amp is not a home-cinema receiver, but rather a complex balanced stereo-amp, in pretty much the upper HiFi segment. Balanced meaning, to simplify this, that it separates the signal all the way, effectively doubling the components in the amp. So in balanced 2-ch mode, there are 4 power-amps in use. The manufacturer then had a genius idea (that never caught on with others) to add one more extra power amp, and 5.1 analogue inputs. And the ability to switch between unbalanced 5 channel mode and fully balanced 2-channel using the remote control. So in a way what it is is an integrated balanced 2-channel HiFi amp, that plays in the league of the pros, but it's also with the press of a button a very competent 5-channel amp, without any digital processing.

But enough of that, there are others who want analogue surround solutions for different reasons, so I know I'm not completely alone in this.

What would I need to make my PC a working digital audio decoder, using external sources? Seems odd that it should be so hard to find this in 2014, but oh well..

All help would be greatly appreciated! Hope you made it through all that text... =)
 
i find it suprising that you didnt think of this since you're into hifi and pcs...

but what you're looking for is basically a DAC.

this can be either external like this one (cant vouche for the quality of this particular one though) http://www.ebay.co.uk/itm/Digital-Dolby-DTS-AC3-Optical-to-Analog-5-1-Stereo-Surround-Audio-Sound-Decoder-/251027680843 or this one http://www.amazon.com/KEEDOX%C2%AE-5-1-Channel-Theater-Decoder-Digital/dp/B008XF7IHW

or a soundcard with optical inputs which support 5.1 over optical. however, these are hard to find anymore (some people blame DRM). i think some older cards like this http://www.newegg.com/Product/Product.aspx?Item=N82E16829271002 support it however they might not support the latest formats.

this could also be a 5.1 processor which is what you mentioned before. this is pretty much similar to a receiver but without an amplifier. they are expensive though however since they are made for "high end" audio what did you expect? http://shop.emotiva.com/collections/processors/products/umc200

i've heard that some video recorders used for computers will accept a hdmi signal (direct from your console) then export it via hdmi to your monitor and allow you to play through your speakers (so you could use the 3.5mm jacks to go to your amp)

there was also talk about a soundcard with hdmi in support in the past but i think that project was busted and the company folded.

also... optical is not the most ideal for audio. the only uncompressed sound is 2.0 over optical. 5.1 is going to be compressed over formats like DDL. you will get the best sound from hdmi. you can find boxes similar to the ones i listed in the first suggestion which can decode 5.1 from a hdmi signal and send it out via rca jacks and then output the video only signal to your tv. some even have two inputs. while i cant vouche for the quality its certainly one way to get it done. like these http://www.ambery.com/hdmulpmpsuso.html and http://www.allaboutadapters.com/hddodtsdihdo.html

its hard to really go against recommending a reciever though. you can get them for $200, they support loads of formats, can handle lots of inputs and can power speakers. if you are using a high end 5.1 amplifier then the only real choice if you want to keep on the same level playing field is a 5.1 processor however they are expensive.
 

finbarqs

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Jul 16, 2014
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I've been looking too, and apparently, only windows XP would allow it. It seems to me all you would need is a software to allow your sound card to decode.. The only problem with a receiver is that it's a receiver. Another power jack, and now you need to do away with your sound card gaming capabilities and have it "encode" into DTS or DDL. (which isn't bad, but it's not what games want)

So the best thing here is if the sound card offer DD/DTS Decode, so all you need is a cable to plug into your sound card and voila! game consoles rejoice with DD and DTS through your speaker system!
 

1031982

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Dec 14, 2014
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As far as I know, only one cards was ever able to do this,the Sound Blaster Audigy 2 ZS Platinum. However, they are all limited to DD 5.1 and DTS 5.1. The licensing for it was to expensive so Creative Labs discontinued the support in future cards, making any of then with the capability highly sought after, and expensive if found. This reason has never been confirmed or denied by Creative Labs, however other reasons have been denied making it most likely.
In addition, there is driver support for Windows XP through Windows 7. There is, and will never be official support for Windows 8 or any future OS's.
I have one, the card supports hardware decoding from internal and external sources from Dolby Digital, Dolby Pro Logic, Dolby Digital EX, DTS, DTS-ES, and DTS NEO:6 to analog.
I use mine to decide the audio from my XBox 360.
You need a PCI slot and an available 5.25 bay in front. You need the included program "Audio Console" to enable it.
 
It sounds like your amplifier is actually a 5 channel amp in which 2 channels can be "bridged" into one, rather than "balanced" which would describe the input type ( XLR connector) and to some degree the circuit design. You mention that you want to support HD lossless formats and these can only be output through HDMI. You will need either a surround sound preamp processor or receiver with 5.1 or 7.1 analog outputs to feed you amp. Trying to do this on a sound card would be more complicated (especially if the PC were a source as well).
 

NerevarReborn

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Jul 10, 2012
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This is an old thread. And yes, I had a surround pre-amp a long while. But for reasons wanted to try and get rid of it.

Anyhow, in my case this is no longer an issue, though the discussuion is welcome to continue for others who would like to have the holy grail of using a PC as a surround pre-amp. Even though it sadly seems close to impossible due to licensing and or limits due to latency.

My balanced HiFi-amp (around $3.500 new like 6-7 years ago) is now scrapped for parts due to some microscopic break in the circuitry that could not be located and fixed, the old NAD surround pre-amp is in storage (simply outdated), and they have been replaced by a Yamaha mid-level surround receiver, that drives center and rear speakers only, and handles any digital signals, and a really brilliant little Norwegian stereo-amp that cost almost a third of my old balanced amp, but actually outplays it in most ways. With HT input, so works as a power-amp for the fronts when I'm in surround mode from the Yamaha. So I'm happy now, even though I was pissed off many times during that journey of realizing very expensive stuff can become completely worthless.
 
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