What is the optimum rca digital cable length?????

The 1.5 meter "magical length" was probably devised by the manufacturers so that they could charge more for a longer length cable. What is the truism about wire, it accounts for 20% of the sales in the industry and results in 80% of the profit.

I have not heard any degradation in using .5m and 1m lenghts for digital audio. However, per Ethernet specs 1.5m is correct but that is a local area network.

Sean is absolutely correct. With perfect impedance matching shortest is best, as it usually is with all non-RF cables.
If the impedances are not perfect then I'm afraid you'll need about $50,000 of test equipment (an RF network analyzer) and the answer will be good only for your specific DAC and transport, and will vary if you change either. Not good, eh !?
It's probably easier to compare a few and pick one you like best.

Sean: One should not need a network analyzer to compare the results of various cables with a specific transport / dac combo. A decent quality scope with a high quality test disc containing multiple test tones / waveforms should allow one to visualize the various loading characteristics taking place.

The bad thing about this is that you might be able to find a cable that allows optimum power transfer with a high level of linearity that is not to your sonic preferences. Does one go with what they know is "technically correct" and hate their system or use what they like and regret not using what is "most accurate" ? I know which path i would take but i'd like to have the best of BOTH worlds : ) Sean
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