[cosmopragma]

I need a soundcard with excellent digital out for a jitter sensitive DAC.
I prefer optical, but coax is also an option.
I don't care about analog out or gaming capabilities.
It has to be better than the RME Digi 96/8 PAD I already own.
How good is your recommended soundcard compared to better CDPs used as transports?
What should I look for when I purchase a cable that doesn't add much jitter?
Thanks in advance.

 

[Mr.Radar]

An EMU 1212m with a modded 1010 (digital) card would probably beat your RME.

 

[Edwood]

Anyone measure the jitter from the outputs of these two cards?

-Ed

 

[dip16amp]

You could also put a Monarchy DIP between the DAC and RME card.
Or have a USB interface installed in the DAC.

 

[Alu]

A little, slightly modded transit

 

[Glassman]

much better approach is to mod the DAC itself so that it will output it's own S/PDIF stream, your RME will lock on it and send data to the DAC synced to it's own master clock

that's the only 100% jitter free transmission..

 

[Daroid]

The problem with "jitter" is that no-one here really measures anything, yet everyone wants to avoid it. It's all pure speculation, guesses and "words from the manufacturer's mouth". You might find this thread a help: http://www6.head-fi.org/forums/showthread.php?t=74074 (the info you want starts at the middle of page 1 or beginning pg. 2).

Do you have other requirements for the soundcard ? i.e. PCI, USB, FireWire etc. ?

 

[cosmopragma]

Quote:

Originally Posted by dip16amp Or have a USB interface installed in the DAC.

How does an USB-interface improve jitter? Does it contain something like resampling/reclocking?
BTW, I was told that there are four different USB protocols for different purposes, and that the relevant mode for time critical audio/video (isochronous mode) comes without a compared to traditional SP/DIF superior error correction.Basically in this mode corrupted data isn't transferred again.

 

[Alu]

So what would be worth more, modding the transit or modding the bel canto dac 2 on empiricalaudio? Or both?

EDIT: way off-topic

 

[dip16amp]

Quote:

Originally Posted by cosmopragma How does an USB-interface improve jitter? Does it contain something like resampling/reclocking? BTW, I was told that there are four different USB protocols for different purposes, and that the relevant mode for time critical audio/video (isochronous mode) comes without a compared to traditional SP/DIF superior error correction.Basically in this mode corrupted data isn't transferred again.

It would eliminate an external cable that would introduce jitter. It would also have to be a low jitter modified USB interface like the one Empirical Audio installs.

 

[dallasstar]

This:
http://audioen.terratec.net/modules....article&sid=23

Combined with this:
http://audioen.terratec.net/modules....article&sid=25

 

[uzziah]

strangely enough, scott nixon mentioned to me that his favorite spdif is the one on the asus deluxe motherboards. haven't got more of an answer than that yet, though

 

[thomaspf]

Has anyone here seen any publication on measured jitter performance of the empirical audio modded USB cards?

I don't even know what a low jitter USB interface is. USB is an asynchronous bus with retransmissions etc.

Then there is an off the shelf chip that is buffering the bursts of audio data and is trying to estimate the the actual data rate at which this is being send. The accurateness of the actual data rate depends on the system timer of your computer OS at this point with the USB audio chip providing some smoothing.

The chip manufacturer (TI) does not publish or claim any extraordinary jitter performance so it would be great if someone could show in measurement that adding an expensive clock to this chip does actually result in low jitter.

This expensive clock is still not being used to actually drive the conversion clock so who knows what happens in the actual DAC.

Cheers

Thomas

PS.: Looking at some of the prices for these mods you are probably better of following Glassman's advice and buy a DAC with master clock out and a cheap sound card with master clock input.

 

[cosmopragma]

Quote:

Originally Posted by thomaspf I don't even know what a low jitter USB interface is. USB is an asynchronous bus with retransmissions etc. .

Again, a rep of a company selling a modern DAC told me that it is common practise to use the isochronous mode in order to be compatible with the plug-and-play Windows USB audio device driver.There are ICs for that purpose already available, in that case from AKM IIRC.
Corrupted data aren't simply transferred twice (or more times if needed) since video applications need proper synchronisation.

That seems to be a typical Microsoft screw-up.
First of all, a delay of let's say 0,05 sec. ìs irrelevant for 2-channel audio.
Second, even a more sophisticated synchronisation scheme allowing nearly perfect error correction is easy to imagine. They just don't care for high-end quality, the simple isochronous mode works for the needs of Tom, Dick or Harry.
AFAIK, and that's not enough.

Well, I will get one of those AQVOX DACs for evaluation next week, but the original questions were targeted to a soundcard for a simple NOS-DAC.Very simple.I'm quite used to modern DACs with plentiful of features, resampling/reclocking, upsampling, oversampling, adjustable dithering and whatnot, but I'm just curious how a raw DAC sounds.Obviously a low jitter transport is paramount here, the modern DACs don't care much for transport or cable quality, but a simple DAC will.

 

[Adriel]

Quote:

Originally Posted by cosmopragma I need a soundcard with excellent digital out for a jitter sensitive DAC. I prefer optical, but coax is also an option. I don't care about analog out or gaming capabilities. It has to be better than the RME Digi 96/8 PAD I already own. How good is your recommended soundcard compared to better CDPs used as transports? What should I look for when I purchase a cable that doesn't add much jitter? Thanks in advance.

Get a Monarchy Audio DIP Classic if 16/44.1 is all you need. Look, Stereophile has many jitter measurements available online, for soundcards, cables, etc. It's not a "speculation". Here's jitter spectrum measurements done on an older version DIP:

http://www.monarchyaudio.com/DIP4.htm

I have the DIP Classic and recommend it. USB by itself does not guarantee anything in terms of sound quality. I have an Ego-Sys Waveterminal U2A USB, which supports kernel streaming. I use it to output optically to the DIP Classic, which then goes to my DAC of choice (SN DacKit w/3xdc power supply unit). The U2A is USB, but its sound quality is very uninteresting/bland/midfi, just like m-audio audiophile etc. etc. any other electronic musician soundcard with akm DAC chips blah blah. That's why USB or PCI soundcards should be used just as tools to get the sound to the DIP, through ASIO or kernel streaming etc.