Jitterless pc audio

[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.

[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.

[MWP]

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.

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.

[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

[lucpes]

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 crap, 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/ .

[lucpes]

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...

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 , because most switching PSUs for PC's use crap 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.

[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/pioneer...k_pqls_dia.jpg . Here is the thread about it http://www.avsforum.com/avs-vb/showt...27#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.

[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

[arniel]

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

[capslock]

The e-mu 1010 based card have an input for an external clock...