Does the quality of a digital signal matter?


I recently heard a demonstration where a CD player was played with and without being supported with three Nordost Sort Kones. The difference was audible to me, but did not blow me away.

I was discussing the Sort Kones with a friend of mine that is an electrical engineer and also a musical audio guy. It was his opinion that these items could certain make an improvement in an analogue signal, but shouldn't do anything for a digital signal. He said that as long as the component receiving the digital signal can recognize a 1 or 0 then the signal is successful. It's a pass/fail situation and doesn't rely on levels of quality.

An example that he gave me was that we think nothing of using a cheap CDRW drive to duplicate a CD with no worry about the quality being reduced. If the signal isn't read in full an error is reported so we know that the entire signal has been sent.

I believe he said that it's possible to show that a more expensive digital cable is better than another, but the end product doesn't change.

There was a test done with HDMI cables that tested cables of different prices. The only difference in picture quality was noted when a cable was defective and there was an obvious problem on the display.

I realize that the most use analogue signals, but for those of us that use a receiver for our D/A, does the CD players quality matter? Any thoughts?
mceljo

Showing 3 responses by paulsax

keep in mind that while digital info is just 0's and 1's there also has to be a timing element that insures that the bits are in the correct place. Easy to get them in order but if your disk is spinning too fast then your read is too fast and such. Mind I'm not advocating anything as I am suspicious of so many things here but I could see timing perhaps being affected by cheap stuff. One problem with isolation is that there is a delay between setups and the listener often knows which is which. Any blind tests out there with multiple listeners and under statistical or sampling control?
Curious. In Jea48's linked article the implication was that the level of jitter was related to or at least different for different frequency levels of sound (presumably after the DAC). Someone straighten me out on this. It seems to me that the bit stream speed is independent of the bit content. If this is correct than should not the jitter be either constant of possible a function of the disc itself (like radial position or burn/pressing quality)?
let me ask a related but slightly different question. I read often of a player being colored. THere is a thread right now about a music hall player being slightly "forward" and "bright". All things equal and in a world where jitter is the dominate error (or am I misunderstanding the tone of this thread?) how does a "color" creep in? Jitter seems like a strictly time domain issue and the coloration of music would seem like a level vs frequency issue? If so that may imply that the DAC or perhaps some outside electronics issue outside of bit reading is at play. Is that a reasonable assessment?

Sorry about the dumb questions. I'm your boy for mechanical engineering / physics / material science but I'm just about the "bang the rocks together" stage with digital electronics!