Hi Lowrider,
Yes, the "dielectric constant" of the insulating material(s) surrounding the conductors in a cable, and particularly the constant of the dielectric material that is between the inner and outer conductors in the case of a coaxial cable, will affect the speed with which the signal propagates through the cable. For various types of coaxial cable that velocity may range, roughly speaking, from perhaps 60% to 90% or so of the speed of light in a vacuum. And that variation can affect the lengths that will be optimal in a given application.
As can many other variables, including the almost always unspecified risetime and falltime of the signal provided by the particular component which drives the cable (risetime and falltime refer to the time it takes for the digital signal to transition between its two voltage states), the impedance accuracy of the two connected components as well as of the cable, the jitter rejection capability of the DAC or other component receiving the signal, the susceptibility of the two components to ground loop issues (which can also be affected by how AC power is distributed to them), and other unpredictable, system-dependent, and probably also listener-dependent variables.
All of which is why I have said in a number of past threads that the recommendation of 1.5 meters (or a bit longer), or alternatively a very short length, should be viewed as providing the best odds of being optimal, but one that will not necessarily be optimal in many cases.
Best regards,
-- Al
Yes, the "dielectric constant" of the insulating material(s) surrounding the conductors in a cable, and particularly the constant of the dielectric material that is between the inner and outer conductors in the case of a coaxial cable, will affect the speed with which the signal propagates through the cable. For various types of coaxial cable that velocity may range, roughly speaking, from perhaps 60% to 90% or so of the speed of light in a vacuum. And that variation can affect the lengths that will be optimal in a given application.
As can many other variables, including the almost always unspecified risetime and falltime of the signal provided by the particular component which drives the cable (risetime and falltime refer to the time it takes for the digital signal to transition between its two voltage states), the impedance accuracy of the two connected components as well as of the cable, the jitter rejection capability of the DAC or other component receiving the signal, the susceptibility of the two components to ground loop issues (which can also be affected by how AC power is distributed to them), and other unpredictable, system-dependent, and probably also listener-dependent variables.
All of which is why I have said in a number of past threads that the recommendation of 1.5 meters (or a bit longer), or alternatively a very short length, should be viewed as providing the best odds of being optimal, but one that will not necessarily be optimal in many cases.
Best regards,
-- Al