CABLE SURVEY

[krass]

Conclusion; a bad cable will have a negative influence on music because the timing can be out. The question remaining (I'm sorry but this is where you'll be disappointed because I don't have the answer) is how bad does a cable need to be before the timing goes out or how good does a cable need to be to get the timing 100%?

Pim

that's where I think there is misunderstanding, the accuracy of the 1 and 0 signal levels is unimportant in this discussion, as f1eng points out. The trigger thresholds have so much margin (from each other and from full scale 0.0 and full scale x.0) that the actual signal level fluctuations introduce no errors concerning bit change detection. For sure there is a rise time associated with every data bit change, but this is controlled by standardized interface specification of the driver and detector circuitry, embedded in every single device communicating digitally.

More importantly, even if there is an effect due to the rise time or clock out differences at the transmitter end, in most cases the clock errors etc are recovered further down the chain. If it wasn't like this then digital transfer just couldn't work reliably for any applications..... in the digital audio domain, the only aspect of audio data transfer that matters is where the final recovery of the clock associated with the audio data is made, the later the better (there are other discussions about power/noise transfer but I only talk about digital data transfer and recovery here)

So it is wrong to generalise about the effect of different cables on the final integrity and timing of digital data. Feel free to blame cables, wires, analogue circuitry etc on timing problems AFTER the final digital clock recovery. Before that, the choice of cable (assuming it meets the standard specification) can make no discernible difference to either digital integrity or final timing.

Taking asynchronous DACs as an example, the data is transferred asynchronously & buffered, with timing regenerated by the clock in the DAC, and the DAC outputs an analogue signal. There is nowhere in such a system where a normal digital cable can make any difference due to either timing or bit recovery integrity (though it is theoretically possible for such cables to introduce other problems, noise/power etc)