Beyond the source of (power) most electronic components are passive and possess the ability to influence energy, (later converted to sound.)  A basic power cord that everybody uses is a good example of a filter that changes the transient response of the incoming power. The A/B test that one could do is to wire an amp with similar 12-14awg romex. The transient response audible in the higher frequencies will decrease and the body of the tone will thicken,,, demonstrating that a cord doesn’t just diminish or accurately reproduce what’s behind it, but can technically evolve it!  The theory behind this?  Electricity does not flow at a constant rate. It can go as fast as 90% of the speed of light through one type of medium and then measure at 40% in a different medium. This is called velocity of propagation. A standard coaxial cable measures around 60% the speed of light.  If you have an additional theory, jump in!