Audiolabyrinth - S/PDIF and USB cables run the gamut and the price is no indication of the sound quality you will achieve IME. I make a S/PDIF cable that is closely matched to 75 ohms, uses silver and expanded Teflon and only costs $250. No customer of mine has found a better cable, and they have tried. Based on my experiments, I believe that it is the termination of the coax to the plug connector that is most critical, not so much the plug-jack interface. The termination of my 75 ohm cable to the 75 ohm BNC is virtually flawless.
The USB cable is another thing however. There are a lot of companies making exotic versions and most don't match the 90 ohm spec. With new XMOS-based USB interfaces on a number of DACs (I'm doing one as well), I have found that the cable makes an even bigger difference. The signal integrity and power delivery are both important for XMOS interfaces.
Gordon Rankin claims that the error rate is high on many USB cables, and this shows up in SQ degradation. I believe that the SQ is mostly impacted by the power in the cable based on my experimentation, at least for XMOS based interfaces. I have a software tool now that logs errors over USB that I can use to compare cables. I have several USB cables and I'll be testing these over the next month or so to see which ones cause a lot of errors.
Steve N.
Empirical Audio
The USB cable is another thing however. There are a lot of companies making exotic versions and most don't match the 90 ohm spec. With new XMOS-based USB interfaces on a number of DACs (I'm doing one as well), I have found that the cable makes an even bigger difference. The signal integrity and power delivery are both important for XMOS interfaces.
Gordon Rankin claims that the error rate is high on many USB cables, and this shows up in SQ degradation. I believe that the SQ is mostly impacted by the power in the cable based on my experimentation, at least for XMOS based interfaces. I have a software tool now that logs errors over USB that I can use to compare cables. I have several USB cables and I'll be testing these over the next month or so to see which ones cause a lot of errors.
Steve N.
Empirical Audio