[PFKDMIAC]

I was hoping there may be a way to do PC audio that would be better. I am looking for ideas,

 

[Prog Rock Man]

Maximise the music manager's and computer's digital volume and control the volume from the amp.

 

[Roseval]

[size=medium]The rate at which SPDIF sends the bits is used by de receiver to generate the sample rate.[/size]
[size=medium]As a consequence, the sound quality is as good as the quality of the clock of the sender.[/size]
[size=medium]Low quality=fluctuations in the RMS=lots of input jitter.[/size]
[size=medium]Some try to solve this by using a top pro-sound card like Lynx or RME to get best possible quality SPDIF out of the PC[/size]
[size=medium]Toslink is great as it completely separates the PC and the DAC electrical but again, the interface is often considered to be high on jitter.[/size]
[size=medium]USB in adaptive mode is much like SPDIF,  in this case the sample rate is derived from the rate the data is pouring in. Again this generates input jitter[/size]
 
[size=medium]USB in asynchronous mode simply inverts the relation.[/size]
[size=medium]Now it is the DAC doing the timing.[/size]
[size=medium]In principle the jitter is reduces to the intrinsic jitter of the DAC and the input jitter is eliminated completely. As the DAC is in control, the quality of the implementation at the side of the DAC is decisive, not the quality of the sender.[/size]
[size=medium]In practice asynchronous USB with a good clock is not enough.[/size]
[size=medium]Good implementations also decouple DAC and PC electrically by using optocouplers or transformers.[/size]
[size=medium]Indeed, Wavelength Gordon Ranking made asynchronous USB famous.[/size]
[size=medium]Today you see a couple of new DAC’s supporting asynchronous USB: [/size][size=medium]http://thewelltemperedcomputer.com/HW/USB_DAC.htm[/size]
 
[size=medium]There are also asynchronous USB to SPDIF converters available.[/size]
[size=medium]http://thewelltemperedcomputer.com/HW/Connect/Convert_connect.htm[/size]

 

[mattkosem]

Quote:

I was hoping there may be a way to do PC audio that would be better. I am looking for ideas,

I believe JKenny's mods to the M2Tech Hiface offer an I2S output.  There appears to be a new model from M2Tech that offers it out of the box, but I cannot find much info on it.  Properly implemented I2S to a DAC would improve your chances of a quality transmission, no?  It would avoid the issues that SPDIF has by skipping it entirely.  You'd need to find a DAC with an I2S input, but they appear to be out there.
 
--Matt

 

[paaj]

Even unmodded (not tried modded) the HiFace is a decent upgrade to the standard optical output on my Mac Mini. Very much interested in the newer version.

 

[jenneth]

Quote:

I believe JKenny's mods to the M2Tech Hiface offer an I2S output.  There appears to be a new model from M2Tech that offers it out of the box, but I cannot find much info on it.
 
--Matt

http://www.m2tech-hiface.com.au/index.php/hiface-evo

 

[audioengr]

 
Quote:

 I actually spoke to Peter about this. If you have a computer with an optical or digital coax out there would be no need to use the USB port and all that jitter is gone.

 
In your dreams.  The jitter from PCI card S/PDIF outputs is the worst I have measured or auditioned.  Even the most expensive ones suck IMO.
 
Best scenerio is to get the converter outside the computer and on its own power supply.  There are hundreds of posts on the forums of folks that have done this, with mods and otherwise.  Clean DC power is critical and clock quality is critical.  Many are using LI batteries.
 
Steve N.
Empirical Audio

 

[audioengr]

 
Quote:

 I believe JKenny's mods to the M2Tech Hiface offer an I2S output.  There appears to be a new model from M2Tech that offers it out of the box, but I cannot find much info on it.  Properly implemented I2S to a DAC would improve your chances of a quality transmission, no?  It would avoid the issues that SPDIF has by skipping it entirely.  You'd need to find a DAC with an I2S input, but they appear to be out there.  
--Matt

 
Certainly I2S connection has the potential for the lowest jitter.  This is why I design it into all of my products.  The problem is that simple DIY DAC implementations do not include a muting function, which is critical to avoiding loud pops.  This can damage tweeters, blow up amplifiers etc..
 
Steve N.
Empirical Audio