The molecular level explanation of "cable burn-in"

I’ll make everyone mad.  The main cable doesn’t effect the product it serves.

Instead, a poorly insulated main acts as an antenna and transmits garbage from inside the component it serves under certain circumstances.

You can test this with a cheap main and a cheap interconnect from different devices.  Tape them together for a bit of a run.  You can definitely pick up a hum or hiss or pop. 

In the typical rats’ nest of wires  behind so many audiophile set ups, you’ll get plenty of touching wires with plenty of parallel runs.  Frequently you’ll get some noise.

Run your wires carefully, try not to let them touch, give everything space, and where they have to cross, do so at 90 degrees (or a sharp angle), and use nice, but not exotic, wires, and all such issues disappear. XLR/balanced wiring and components helps a lot, too.  
 

The most sensitive run is from your turntable.  Any issue there is multiplied along and it’s the weakest signal in the chain.  Run it balanced (or however one wants to describe it) if you can.

All the exotic wires, difficult to repeat issues, difficult to test, issues are explained by the above.

Source:  I was an electronic countermeasures officer in a rather long and unpleasant war, and would face things like components working differently when one was placed on top of the other and not the other way around, that no Raytheon engineer could explain but sure as Hell happened consistently. 

@dougthebiker 

“If you can't tell the difference between cheap and expensive cables, your system isn't very resolving or you've got the speakers in the wrong place”

Maybe.  Or the set up doesn’t have the interference the fancy cables are solving in another situation.  Or the components were designed to use the wires being used.

It’s all very situationally dependent.

My mom had alcohol issues and once used a zip cord on me. To her surprise the evidence appeared the next morning in the form of red welts. She put long sleeves on me and buttoned up my top button before sending me off to school.  These days I can appreciate a better cable in a different manner.

Seems as plausible as any other 100% subjective theory, which they all are.

@classicrockfan

Interesting topic.

I find that the technical explanation of "observable" phenomena can take the following path(s):

Nothing observable happened. Therefore every explanation to validate it is BS.

Something did happen. The entirety of supportive explanations are valid.

Something did happen. But, our attempts to describe what we observed are invalid.

The case above, it’s an automatic reflex to reject all of the explanations if some of the explanations are invalid -- in OUR view even though there is a (growing) body of evidence to show something is real here. Taking an example of an individual finding a mere 20% of the talking points to be "true", that means that the vast majority of the details are not true (in their opinion). What about the other 20%? Do we reject the premise entirely even though there are proven elements to the premise?

I find it interesting, that groups of people with pedigrees as long as their arms can reach totally opposite conclusions on many subjects; some a matter of life or death. So, it comes down to motivation. What’s in it for them?

Are they trying to save the world from bad sound? Trying into make a buck? Attempting to maintain their SGR (Smartest Guy in the Room) status? Just enjoying lively conversation? Every fiber of their being is wrapped around this, and the penalties for failure are severe? (job, status, potential prison sentence ...). And, yes, there can be multiple motives -- save the world from bad sound AND make a living in the process. These are not always contradictory but can be rather complimentary.

The atomic expansion theory states that all atoms in the universe are expanding at the same rate, so we don’t observe anything changing. Right? Wrong? I don’t know. It’s well above my pay grade. But, it’s fun to watch the really smart guys on both sides of the issue duke it out. With no clear winner.