I think we'll wrap up the series on breakin today. We've covered some ground, I'll cover a bit more in this post. It's a subject we can always return to when the mood strikes.
I've found very few pieces of the hifi system puzzle that don't benefit from breakin; some more, others less. Readers write me and suggest their connectors break in and I have to question that observation; it's not one that I've experienced. But wires seem to break in and I've heard many a cable go from tight sounding to open and musical over a day, even a week. So, why should wires break in?
My guess on wires has more to do with the insulators and less to do with the wires themselves. I simply struggle with the notion that copper breaks in over time, but the insulators are easier for me to grasp. If you'll recall our discussion on capacitors, we learned that a capacitor is a sandwich of insulating and conducting materials. Sounds kind of like a wire, when you think about it (and I often do).
Insulating materials change the sound of cables in our music systems. When I immersed myself in the design of PS Audio's cable line, some years ago, I ordered a variety of cables with different insulating materials and constructs; and there were many: Teflon, PE, PE foam, PVC, XLPE, EPR, paper, even air. At one point, I had managed to get identical sets of copper interconnects, each with a different insulating characteristic and all sounded different, some dramatically so.
The whole subject of insulators started years ago when I had learned the best sounding insulator was air, and built a set of air-cables. These were simple twin-lead cables, separated with nothing more than masking tape. Their electrical insulating properties were achieved by distance (air) and no material we could find sounded better. They had no shielding, were susceptible to hum and RF, but when they worked, they were amazing.
So other materials, like those I just mentioned, are attempts at getting closer to the sound of an air insulator, while making a practical cable in a compact shielded form. Some of the best sound I found was from PE foam. PE is polyethylene, a low cost plastic that bags are made from. By injecting air into the plastic when it is being molded, a light foam is created and sonically we get closer to the ideal of air.
And every one of these materials sounded different than the other and, to the point of this post, each improved over time and with use in an electrical circuit.
My theory on all this is a simple one. We live in a physical world where nothing is constant and everything is impacted by the way it is treated.
Materials differ when an electrical signal is present and some of these differences change what we hear.
Not all of us have experienced break in. But for those that have, it is unquestionably happening to some degree in our systems.
For those that have not experienced it, the phenomena will remain a mystery, perhaps a source of endless ammunition for the cynic within us.