Understanding Jitter in PC Audio


I have a fundamental doubt on the PC audio as a source. IN a traditional CDT/Dac combination we have a clock signal coming out in the SPDIF signal. Apologies if it sounds too silly but am planning of builing an HDD based transport as an alternative to my classe CDT1 :). was planning on a USB output from a dedicated PC and then use a good USB to SPDIF converter.

My Understanding is that in case of a HDD based transport, the File is converted into an Async format (Lossless) . This is then played via a PC/Mac and when given out as digital out, the clock that is synched to is the machines own clock (Am I right ?)

a) does this impact jitter of the Lossless file in anyway ? also what would the difference between an I2S and an USB interface be in this case as the clock is not really the original clock ?
b) Can the original information without any timing errors be reconstructed from this using an external reclocker like the empirical audio device OR Monarchy ?
c) If the clock is not present will an external DAC just assume the input to be as per its own clock. (If the rip were done by CDROM using the same clock freq as a DAc give any added benefit)
arj

Showing 2 responses by shazam

Arj,

referencing your original question about I2S, if you have the patience to wait a few months, I think we will start seeing more products trying to use a native I2S interface. PS Audio's new Transport and DAC will be making an I2S connection using HDMI plugs/cables. My hope is that others hop on the bandwagon and begin using HDMI to transmit in native I2S format. Since HDMI cables and plugs are readily available for other purposes, the market barriers to entry are significantly lower for this application.

This would represent a major technology upgrade to one of the weakest parts of PC and digital audio. I have a hard time imagining everyone NOT jumping on this once industry heavies like PS Audio take the lead. I'm also betting (hoping?) custom shops like Steve at Emperical will be able to modify a SqueezeBox or Sonos with an HDMI I2S connection while we wait for manufacturers to ante up.

If the industry could standardize on HDMI components to transmit native I2S, we could kill off the crappy optical and SPDIF connections we use now and virtually eliminate the need for expensive re-clockers (sorry about that part, Steve).

My $.02. In a horrible economy, people aren't going to plunk down big money for something unless it makes a big difference for them. I think this could be it.