Jitter makes it’s way into things everywhere it can. Even the DAC receiver and buffering add jitter. Cables don’t produce noise, but ground-loops do and dielectric absorption in the cable can distort the waveform causing ISI (inter-symbol-interference). Reflection on the cable can cause a LOT of jitter, but this can easily be minimized by using at least a 1.5m long cable.
Ethernet signal integrity issues can easily be minimized using isolators and high-bandwidth cables of the optimum lengths.
Steve N.
Empirical Audio