Standalonel DAC and 5.1 audio

sk88

This may be a dumb question. Since I am going to store all my music (flac) on my PC, I am looking for a DAC that would connect the PC to my audio system (not sure what it is going to be yet). Most of the DAC take input from a combination of usb, optic, coaxial or analog. The output are just two channel analog.

My question is, if I play 5.1 surround on the PC into the DAC, would the DAC somehow "destroy" 5.1 (since it outputs only 2 channels) or would it maintain the 5.1 encoding and send it to the audio system for decoding into 6 channels? Does it matter how I would connect the DAC to the PC?

falconcry72

A standalone 2-channel DAC will not be able to read an incoming 5.1 channel signal. It will not output any audio.

What are you trying to accomplish here?

Is there a Surround Processor or AVR in the mix here? You could connect your PC to the standalone DAC via USB for 2-channel audio, and then connect your PC to the Surround Processor via a soundcard with a SPDIF output for 5.1 channel audio.

EndersShadow

falconcry72 wrote: »

A standalone 2-channel DAC will not be able to read an incoming 5.1 channel signal. It will not output any audio.

What are you trying to accomplish here?

Is there a Surround Processor or AVR in the mix here? You could connect your PC to the standalone DAC via USB for 2-channel audio, and then connect your PC to the Surround Processor via a soundcard with a SPDIF output for 5.1 channel audio.

^This is the only way to get what you want, otherwise if you use a DAC with optical out, your not really getting as much in return.

zingo

Do you have many 5.1 audio files on your PC?

Tbone289

EndersShadow wrote: »

^This is the only way to get what you want, otherwise if you use a DAC with optical out, your not really getting as much in return.

Well, yes, the only way to get what you want is to separate your sources for 2-channel (stand-alone DAC) and 5.1 channel. However, there are choices other than using SPDIF from a soundcard for the 5.1 source.

mantis

No DAC takes analog in.

EndersShadow

mantis wrote: »

No DAC takes analog in.

ignore me, mis-read

nwohlford

A DacMagic will pass a 5.1 signal from its digital input to its digital outputs. (The analog outputs are muted when it receives a 5.1 signal.) I have never tried this with a 5.1 from USB, so I am not sure how feasible it is. I am curious now and will have to try it out.

sk88

To answer the what I am trying to achieve question -

I see my future not owning much cd or dvd alike anymore. I see I get audio or video either through online purchases/downloads or via internet streaming services. In any case, that means I'll rely on a PC/laptop as my main media server and streaming device.

With that said, I do want to make sure I enjoy high quality sound from this system that I am trying to create. And I hope I can use it for pure audio (2-channel or with surround) or video with sound (movie). I understand sound effects in movies generally don't require high sound quality. However, the convenience to use one system for dual purposes is very attractive.

Back to audio, I tried several audio recordings done in 5.1 surround in flac format and I played them on my PC. I can see that they are turly 5.1 music but due to my current system I can only hear in 2 channel stereo. I imagine a symphony heard in 5.1 must be so much better than in stereo (the sound field and separation). So my first question here is what would I need to ahieve 5.1 sound? A home theater AVR with built in DAC and decoder seems to be an easy answer. If it has pre-outs then optionally connect to separate power amps seems to be a better answer. If this is correct, a separate DAC doesn't seem to have a place here.

Putting 5.1 or 7.1 aside which are all digital surrond format transported via optics, HDMI or coax, I read that Dolby Surround (3ch), Dolby Pro Logic (4ch) and Doby Pro Logic II (4.1) are all analog surround format and are all done via two discrete channels (the 4-2-4 process) transported via RCA or XLR. It means to me that via the left and right analog ports, we should be able to transport those surround sound to a decoded (like an AVR such as my old str-gx800es) and get multichannel output.

So, my second question here is if I play one of those analog surround encoded music on my PC and I send the audio output via let's say USB to a DAC, and then the DAC hands off two analog channels to my AVR, would my AVR still see the multichannel encoding?

EndersShadow

If you are doing streaming/downloading for music, your going to get compressed file types and the DAC really wont live up to its full potential. Thats the rub of the situation.

Amazon, iTunes, ect offer low bitrate music for download. There a few places that offer high rez file types and some streaming services that are higher quality (MOG is the only one I am aware of).

If your using MOG then I could see a DAC as an option, but if your thinking Pandora to a DAC its simply not going to be a good return on your investment. Same with music.

sk88

I wonder how people do with high rez multichannel music, either from their collections on a hdd or dvd-a, sacd?

EndersShadow

sk88 wrote: »

I wonder how people do with high rez multichannel music, either from their collections on a hdd or dvd-a, sacd?

I believe most use a CD player for DVD-A and SACD and either use multi-channel analog outs or HDMI when possible.

BlueFox

NAD makes a DAC with an HDMI input, so you can use your Bluray player to play Bluray music disks. However, I think it only handles two channel over HDMI.

sk88

Keiko wrote: »

I've owned an aios for about a year now and use it primarily for storing lossless flac files on a 2TB HD and playback through my rig.

It does look like a small gem. Can't even buy a barebone motherboard with that price.
One of the amazon reviewer mentioned that "my surround processor wasn't able to detect digital audio from the AIOS no matter what I did. Even though I set both HDMI and SPDIF output to RAW, my surround processor only played audio in Prologic mode from the AIOS".

I wonder if you have tried and does it really not work on passing digital surround over digital output? And what's the 6 RCA ports on the back? The picture is not so clear.

sk88

Keiko, thanks for following up on this. I think I may just use a laptop for this function running as a media server. I just need to figure out how do I connect it to a 5ch amp or something.

sk88

This 2 year old link shows some hope for me.
http://www.avforums.com/forums/laptops-netbooks/1279148-5-1-surround-sound-dd-dts-laptop-av-receiver-step-step-guide.html

sk88

Another FYI, laptop running JRiver bitstreaming 7.1 audio to AVR over HDMI maybe what I am looking for. Since it's bitstreaming, all the sound qualities are not altered by the laptop (it's all digital). The D/A conversion would be done by the AVR. I am sure it'd be the same on playing 2ch audio.

http://yabb.jriver.com/interact/index.php?topic=74018.0

I think I've answered my own question. An external DAC that people commonly talked about is only for 2ch audio - which may carry audio surround channels but they are not true discrete channels. For digital surround such as Dolby TrueHD or DTS-HD, those are true discrete channels and they must be handled digitally which means only through a digital interface such as HDMI.

slider2828

Take a look at Audio-GD.... they have some pretty highly regarded DAC5.1