What is "break in" and what difference does it make? In amps? Preamps? Speakers? More?

I suppose ignorance regarding the fact that interconnects ALL comprise an, "RLC" network, to some degee, is fairly widespread.      The, "C" is for, "CAPACITANCE" and- like any capacitor; the dielectric will take time to stabilize.      The higher the quality of dielectric, the longer the stabilization period.      I’ve always personally held that Dielectric Absorption has much to do with the way capacitors and cables sound.      Especially, given that the better the dielectric (ie: Teflon/Polypropylene/Polyethylene/etc), the lower the absorption figures will be.      https://www.sciencedirect.com/topics/engineering/dielectric-absorption      Of course, there are those that deny that science, with regards to the sound of a system.      https://www.elandcables.com/the-cable-lab/faqs/faq-what-is-capacitance

I suppose ignorance regarding the fact that interconnects ALL comprise an, "RLC" network, to some degee, is fairly widespread.

Dielectric absorption can be real and can also be completely unproven to make any difference at all in a given system, or the effects could be relegated to nano and pico volts of difference. Proving something has a mathematical difference is very very far from calling it perceptible.

Like vibration isolation devices, would be super easy to measure differences in actual reproduced sound, but strangely enough no one ever has.


In the end, if you personally can't hear it, it's worth ZERO dollars. If you can hear it, is it worth any dollars? That's still up to the buyer.


Best,

E

instead of calling it "break in" we should really call it "interval of stability". 
from the time an electronic component is made until the time it eventually goes out of service every single part in that component is undergoing physical and chemical changes.   
"interval of stability" is the time it takes for a newly made electronic component to reach a point in its life where it has reached a relative stability, that is where the rate of change has slowed to the point where it has become relatively stable.  

It should be mentioned that cables and electronics never completely break in as much as we would like to think so. The reason I say that is even when heroic means such as the expensive Cable Cooker are employed to break in cables the process should be repeated every year or whatever as the cables tend to revert back 🔙 to their former state over time. The music signal itself is not sufficient to do the job completely or to maintain that level of performance. By deduction, the lower signal cables and wires in the components behave similarly, and are probably even more resistant to complete and thorough break in.

Read my "Audiophile Law: Thou Shalt Not Overemphasize Burn In" at Dagogo.com

I am not interested in debating my findings.