| tomtommorrow |
There have been many discussions on the quest to acheive high end audio through the PC employing an array of techiniques and design. I am not an electronics expert but I do know quality audio when I hear it.
I just purchased the Pionner VSX-55TXi receiver and DV59-AVi multi-format disc player and found the ilink audio technology included with these products to be outstanding.
Question: Has anyone seen or heard of a way to send audio from a PC to an ilink or firewire equipped receiver through the firewire port of the PC?
It seems fairly clear from many of the other posts that there are 2 fundamental problems with PC audio.
1. DAC by the sound card whether using analog or digital out. If you have spent time and money on a custom or commercial DAC then why have your sound card involved at all?
2. Jitter. Without getting into the details of jitter ( of which I know little about), I think it would be safe to say that if the 1's and 0's of digital audio are not being delivered on the right clock then you are probably going to have some sound degredation.
Avoiding these 2 problems will enable PC audio to do what it does best. Managing large volumes of WAV files ( can we please stop the charade of pretending MP3's or any other compressed format "sounds just as good").
Pioneer, Denon, and Yamaha I believe are the only companies currently offering ilink/firewire audio. Due to copyright issues all three companies are very ambiguous about using the PC with their products.
Using the firewire port of your PC to pass pure jitterless digital audio to an external DAC seems to be the answer that many people are looking for and posting about. |
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| emuman100 |
| Transmitting digital audio by S/PDIF will sound the same if it's being transmitted with ilink or firewire. There is no difference. I take the coax output from my sb audigy and convert that to TTL, then the TTL gets converted to RS485 by a MAX3443 RS422/485 tranceiver. This differential signal gets transmitted via twisted pair with absolutely no noise pickup and very little reflection. Jitter is not even noticable with a CS8420. The differential signal gets received by another MAX3443 and converted to TTL. This TTL signal is converted to coax levels and is inputted to my DAC that uses a CS8420 and a CS43122. jwb did a damn kick *** job on the design. You get the same audio quality with any digital transmission. Most S/PDIF receivers reclock and jitter is not a problem. |
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| MWP |
| quote: |
DAC by the sound card whether using analog or digital out. If you have spent time and money on a custom or commercial DAC then why have your sound card involved at all? |
Because a DAC is only one part of the PC -> Audio conversion.
DACs by the normal meaning recieve either I2S or SPDIF formats.
There has to be somthing in the PC to transmit I2S or SPDIF... that is what a soundcard does.
| quote: | | Using the firewire port of your PC to pass pure jitterless digital audio to an external DAC seems to be the answer that many people are looking for and posting about. |
Nothing is "jitterless" all you can do is try and reduce it and the effects of it.
Stay away from any product/manufacturer thats branded as being such as its obvious marketing hype.
In the case of Firewire (and maybe ilink, i dont know the details about this interface), itll still be up to the transmitting unit (PC) and the reciever on how jitter free the signal is. |
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| Giorgio |
By the way, the jitter in a (GOOD) audio card can be lower than in an good average transport...
The electric and magnetic noise caused in power supply lines by a transport are really VERY bad.
I have an old portable CD player, and, especially if you use a smallish PSU, tracking the input voltage level you can see it moving continuously and instantaneously between 6 to 11V....
You can imagine how fast and how much current absorption does change in any CD transport, and which can be the effects on surrounding circuits, especially if there is a single PSU...
Kind regards
Giorgio |
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| lucpes |
| quote: | Originally posted by tomtommorrow
Avoiding these 2 problems will enable PC audio to do what it does best. Managing large volumes of WAV files ( can we please stop the charade of pretending MP3's or any other compressed format "sounds just as good"). |
MP3s or any other form of lossy compression are more or less ****, agreed, but there are lossless formats around (decoding is bit-to-bit identical with the original wav): http://flac.sourceforge.net/ or http://www.monkeysaudio.com/ . |
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| lucpes |
| quote: | Originally posted by Giorgio
By the way, the jitter in a (GOOD) audio card can be lower than in an good average transport...
The electric and magnetic noise caused in power supply lines by a transport are really VERY bad.
I have an old portable CD player, and, especially if you use a smallish PSU, tracking the input voltage level you can see it moving continuously and instantaneously between 6 to 11V....
You can imagine how fast and how much current absorption does change in any CD transport, and which can be the effects on surrounding circuits, especially if there is a single PSU...
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There's no reason not to replace PSU caps in a PC with better ones (Rubycon ZL 16V/3300uf or bigger if it fits) - it really helps :D, because most switching PSUs for PC's use **** taiwanese caps that go bad in two years or so, or local decoupling caps on the soundcard with SANYO OSCON for the chip / digital section and say Panasonic FC for the rest. But that's a compromise in relation with a good transport with properly built, separate PSs, lots of HF garbage inside the PC. |
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| Gordon McGregor |
I-link is definitely a jitterless connection, here is an example how it works in AV/C mode http://www.areadvd.de/images/pionee...nk_pqls_dia.jpg . Here is the thread about it http://www.avsforum.com/avs-vb/show...627#post2874627 .
In the end of this thread you can find some information about successful connection of 55TXi to PC, but it is not jitterless as AV/C mode can't be used, therefore it is not better then SPDIF, if not worse.
i-link is not jitterfree, that is true, but jitter is relative to the clock used for DACs, nothing else. So we can call it "jitterless".
SPDIF or current implementation of HDMI is not equal to i-link, as the sync frequency should be restored using PLL circuit. |
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| Progg70 |
Need I really take the SPDIF signal out from the sound card? Can’t I take the SPDIF signal directly from the DVD-rom.s connection?
I have a ASUS 16X with play buttons so I don’t need any computer to control it.
Progg 70 |
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| arniel |
| quote: | Originally posted by Progg70
Need I really take the SPDIF signal out from the sound card? Can’t I take the SPDIF signal directly from the DVD-rom.s connection?
I have a ASUS 16X with play buttons so I don’t need any computer to control it.
Progg 70 |
Just a guess, but I think the SPDIF output from the drive is likely only to work when playing Audio CDs, NOT DVDs/DivX files etc. which are decoded by the PCs CPU.
It's also a lot more flexible to use the soundcard's output as that opens up opportunities to take advantage of what PCs can offer e.g. DRC.
Arnie |
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| capslock |
| The e-mu 1010 based card have an input for an external clock... |
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| tomtommorrow |
This company has come up with a multi channel audio solution that utillizes the firewire transport. You can check out the data sheet and overview here http://www.oxsemi.co.uk/pages/ieee1394/index.html
I emailed the distributor for this chip and they sent me a sample. Looks like it might be a bit out of my league, but I am sure there is someone out there who would love to tinker with this chip. Good luck.
tomtommorrow |
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| Gordon McGregor |
The chip for i-link transfer is presented for a long time already, it is Ice-Lynx Micro (http://focus.ti.com/lit/ds/symlink/tsb43ca43a.pdf), manufactured by TI. It is not that easy to implement it though, as one have to get the licence from 5C to use it ... AFAIK.
There is no information anywhere that Oxford semiconductor's chips support A&M protocol and AV/C mode ... |
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| nuppe |
Hi
The TSB43CB43 version doesn't inlcude the 5C-cipher, so that could be used without a license. There is also a later model called TSB43CB43A, don't know what the difference is.
Another chip (that hasn't been released yet) is the Dice II.
It looks like an überchip from the specs, but i don't know if it includes 5C or not.
The Oxford datasheet says something about isochronous audio transfer, which in my ears sound like ICE 61883-6 support, but it is a little vague, it might not be a complete implementation.
About the cipher-stuff, could there be compatability problems not having cipher support? As i understand, you can't connect an output device with cipher to an input device that doesn't include cipher. Would this be a problem for pc-connections? Is it possible to stream unciphered audio from a computer?
I guess there has to be some way (maybe it's even the default mode)...
It would be a nightmare to make something as advanced as this on your own, just to find out you can't use it because of copy-protection.:smash:
Regards
Andreas |
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| jdybnis |
Soundcards aimed at the pro market have input for an external clock signal. Capslock mentioned e-mu. Lynx and RME are two other brands. If your DAC outputs a clock signal, you can feed the clock signal into the transmitting soundcard to control the overall rate of data it sends. Then use a FIFO buffer to reclock at the DAC independently of incoming jitter.
This is nice because there is no soldering required on the soundcard end of the link. |
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| Gordon McGregor |
| quote: | Originally posted by nuppe
Hi
The TSB43CB43 version doesn't inlcude the 5C-cipher, so that could be used without a license. There is also a later model called TSB43CB43A, don't know what the difference is. |
"A" version has 5C encryption, it is the difference, as stated in the provided above data-sheet.| quote: | It would be a nightmare to make something as advanced as this on your own, just to find out you can't use it because of copy-protection.:smash:
Regards
Andreas |
It definitely is ... after Ice Lynx they use Rate controller chip, which is a microcontroller with unknown software ...| quote: | Originally posted by jdybnis
Soundcards aimed at the pro market have input for an external clock signal. Capslock mentioned e-mu. Lynx and RME are two other brands. If your DAC outputs a clock signal, you can feed the clock signal into the transmitting soundcard to control the overall rate of data it sends. Then use a FIFO buffer to reclock at the DAC independently of incoming jitter.
This is nice because there is no soldering required on the soundcard end of the link. |
I use Lynx L22 soundcard with that feature. The problem is that we can't get High resolution crypted signals as 24/192 DVD-A or SACD through SPDIF, as we can do using i-link ... |
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| jdybnis |
| quote: | | I use Lynx L22 soundcard with that feature. The problem is that we can't get High resolution crypted signals as 24/192 DVD-A or SACD through SPDIF, as we can do using i-link ... |
You can't decrypt DVD-A or SACD anyways so what's the point? You can get 2-channel 24/192 over SPDIF, and you can use multiple SPDIF outputs in parallel. |
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| Gordon McGregor |
| quote: | Originally posted by jdybnis
You can't decrypt DVD-A or SACD anyways so what's the point? You can get 2-channel 24/192 over SPDIF, and you can use multiple SPDIF outputs in parallel. |
Decrypt - where? Anyway I need something for that purpose, so what is the point to use SPDIF if I can use I2S after decryption? |
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| jdybnis |
Gordon,
I don't think we're both talking about the same thing. I'm talking about how to get a digital audio signal from a PC to an external DAC. Sorry if I repeat things you already know.
I suggest using a soundcard. It can be SPDIF, I2S, AES/EBU, USB, Firewire, or whatever, as long as you have a reciever for it on your DAC.
Firewire or another asynchronous solution would be optimal, but firewire is complicated to implement. Another optimal solution is to use SPDIF, I2S, etc. going from the soundcard to the DAC, plus a clock signal going from the DAC back to the soundcard. This sychronizes the soundcard with the DAC so you can use a FIFO on the DAC to reclock the audio signal.
This works with as many channels as your PC can output and your DAC can input. If you have a multichannel DAC and a soundcard with 6 channels of digital output (i.e. 3 stereo pairs) then you can play 5.1 audio.
If you want to play a DVD-A through your PC you also have to worry about decoding it, no matter what kind of interface you have between your PC and DAC. AFAIK there are no software DVD-A decoders available or hardware decoders availible without a license. But that is a separate issue.
-Josh |
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| jkeny |
Anybody point me in the right direction - looking for a way of outputting multiple channels of digital signal from PC to digital amplifier, something like pannasonic SA-XR*.
Audio on hard disk in lossless compressed format - Looking to implement digital crossover in PC (using Brutefir) and possibly later Digital Room Correction.
Two way speakers - so 4 channels of digital signal - didn't wan't to go through soundcaed DAC to analog then into panny digital amplifier through it's ADC then digital amp then out to speakers
Is there no way of outputting PCM (after brutefir has done its thing) through ethernet card and into dig amp (maybe patching into internals of panny to PCM channels after ADC?
John |
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| deandob |
John,
Have you found this thread yet?
transferring multichannel digital audio
For stereo, I like the idea of using a soundcard with clock inputs & slaving the soundcard clock from the DAC. Simple & effective to ensure a high quality transfer.
Regards,
Dean |
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| jkeny |
Thanks Dean - yes I read this already but it is too complicated for me and requires soldering skills beyond me.
I was hoping to avoid external DAC by using digital amp.
Is there no software that can route raw WAV audio (PCM) to ethernet card?
ALternatively what is the best hardware solution - medi centre controller?
John |
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| rfbrw |
| quote: | Originally posted by jkeny
<snip>
Is there no software that can route raw WAV audio (PCM) to ethernet card?
<snip>
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And then what? Do you plug an RJ45 into your amp? |
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| jkeny |
| quote: | | And then what? Do you plug an RJ45 into your amp |
I think you can patch into PCM feed in panasonic all digital amp - just after the ADC for instance?
Why not think about it before writing it off so quickly
John |
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| jkeny |
Maybe I didn't think about it!! - PCM over ethernet would require an ethernet card at receiving end etc etc.
Has nobody done this? PCM signal from PC or (CD player) tapped into PCM signal input on digital amp?
john |
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| Gordon McGregor |
| quote: | Originally posted by jdybnis
Gordon,
I don't think we're both talking about the same thing. I'm talking about how to get a digital audio signal from a PC to an external DAC. Sorry if I repeat things you already know.
I suggest using a soundcard. It can be SPDIF, I2S, AES/EBU, USB, Firewire, or whatever, as long as you have a reciever for it on your DAC.
Firewire or another asynchronous solution would be optimal, but firewire is complicated to implement. Another optimal solution is to use SPDIF, I2S, etc. going from the soundcard to the DAC, plus a clock signal going from the DAC back to the soundcard. This sychronizes the soundcard with the DAC so you can use a FIFO on the DAC to reclock the audio signal.
This works with as many channels as your PC can output and your DAC can input. If you have a multichannel DAC and a soundcard with 6 channels of digital output (i.e. 3 stereo pairs) then you can play 5.1 audio.
If you want to play a DVD-A through your PC you also have to worry about decoding it, no matter what kind of interface you have between your PC and DAC. AFAIK there are no software DVD-A decoders available or hardware decoders availible without a license. But that is a separate issue.
-Josh |
Josh,
I was definitely talking about the different solution, If we need to transfer the digital data from PC to the external DAC without thinking about High-Res formats, your offer definitely makes sense.
Concerning mentioned here receiver, we still need to modify it to get the word clock output to sync the soundcard and that will require some soldering, AFAIK. |
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| jdybnis |
John,
A digital amp like the Panasonic IS a DAC. Just a very high power one. |
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| rfbrw |
| quote: | Originally posted by jkeny
Maybe I didn't think about it!! - PCM over ethernet would require an ethernet card at receiving end etc etc.
Has nobody done this? PCM signal from PC or (CD player) tapped into PCM signal input on digital amp?
john |
I would imagine lots of people have. They simply used the digital I/O available on many sound cards. |
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| xdissent |
| yeah.... i'd have to say its odd that no one has a real solution as simple as dig out to dig in. its kind of weird. an ethernet card wouldnt work... but not without a LOT of soldering and programming your own pic or similar microcontroller to decode the data. good idea though. what sucks is the really fast interfaces like firewire and usb 2 are really difficult to work with (*******s) and require a lot of processing on recieving end as well... you'd probably have just as good a shot trying the ethernet thing (realistically you wouldnt get as much data as fast though). its amazing how many times i've seen incredible daw's and banks of super expensive dac's being driven in and out of a sblive or equivalent consumer based sound card. what i plan on doing is tracking down one of those adat light pipe io cards and using my adat's for conversion into an analog amp. i like the dacs and the card is pretty cheap. if your dac or digi amp has light pipe in, this could be one option. there are some decent cards out there that dont use crappy interfaces, but they may not have analog out at all. |
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| rfbrw |
| quote: | Originally posted by xdissent
yeah.... i'd have to say its odd that no one has a real solution as simple as dig out to dig in. |
AES/EBU SPDIF
ADAT
S/MUX ADAT
More than enough for home use. |
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| John Hope |
Hi everyone
I looked into this Firewire issue with a view to getting SACD and DVD-A audio data to my digital amp and then extracting it into some sensible form like I2S/SPDIF/DSD that real audio people can understand!
Neither the TI Ice-Lynx chip nor the Oxford Semi chip are true 'drop-in' interfaces, and to implement what should conceptually be "piece of wire" becomes a ridiculously complex job.
What I thought of doing was this: I believe there are now commercial PC-sound cards which provide both Firewire and multiple channel SPDIF connectivity. (Top end Creative Labs?) So why not use a small PC (with sound card + DVD drive) as the 'player' in your audio system? It's not likely to be anymore cumbersome to use than a modern DVD-player with it's endless reams of menus and options and 'please waits'. You can probably scrounge up the PC for very little cost; the greatest outlay will be on the sound card.
John Hope |
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