I have training in electrical engineering as part of one of my doctorates - I am a professor at a medical school. I am an experimentalist as well as a theorist.
My audio system is relatively expensive, all digital with a master clock. The power cord and the ground station made a huge difference, as did the power cord to the master clock and the BNC digital cable from the master clock to the DAC/CD/SACD/network player configuration.
My experience was that the line was quite noisy including injection of noise from the components, but now there is no noise and all recordings (streamed or from a hard copy) sound spectacular. I think that folks with very inexpensive audio systems may not experience the benefit of expensive cords and many who are critical of such upgrades do not actually listen to music with the same intensity that we do...
My audio system is relatively expensive, all digital with a master clock. The power cord and the ground station made a huge difference, as did the power cord to the master clock and the BNC digital cable from the master clock to the DAC/CD/SACD/network player configuration.
My experience was that the line was quite noisy including injection of noise from the components, but now there is no noise and all recordings (streamed or from a hard copy) sound spectacular. I think that folks with very inexpensive audio systems may not experience the benefit of expensive cords and many who are critical of such upgrades do not actually listen to music with the same intensity that we do...