cable break in

Not a joke.
Read any introductory book on Electro-statics and there you'll find an answer.

The break in period depends on the conductor, conductor geometry, and dielectric. Ask any good cable designer; pay very little attention to free advice offered by those who quote introductory books as their source.

Marakanetz: I haven't the knowledge to debate what you say, but again, the cable manufacturers state that it takes awhile (the break-in time) for the insulation/dielectric to react/respond to the current flowing in the conductor. And that after a time, the molecules in the insulation material (usually foamed Teflon these days) at the interface with the conductor are altered by the current flow in a way that creates even better dielectric properties than when new.

What I don't understand (assuming that's all true) is why it makes any difference to the Teflon which way the current is flowing, since it's non metallic. Probably has to do with Quantum Theory, of whaich my knowledge is rather shallow.

If you have a high-resolution system, you can definitely hear a difference in brand new, unbroken-in cables and cables that have been properly broken in. I don't presume to be able to explain the physics of exactly what's going on here, and it may vary considerably from cable to cable, given the great diversity of designs, but anyone who has had much experience in this realm can confirm this; it's definitely not audiophile neurosis or hocus-pocus.

Within the past year I had the experience of ordering a complete new set of Purist Musaeus cables (two sets of interconnects and one set of speaker cables). When I initially hooked them up, I was somewhat disappointed. The manufacturer stated that the cables required a minimum of 100 hours of burn-in. Well, I might once have been skeptical of such a statement, but I can confirm from personal experience that after 100 hours, this set of cables sounded quite audibly better--smoother, better balanced, with better resolution of detail--than it did when brand new. Later I ordered an additional pair of new Purist Audio Musaeus interconnects, and the same experience was repeated: they sounded quite audibly better when they had completed break-in. This experience has been repeated by so many audiophiles that it is commonplace and well accepted by those who aren't so blinded by theory or what some textbook told them that they won't believe what their ears tell them.

cable manufacturers as well as dealers interested to pitch their product. thus to explain rediculousely high prices, sound becomes better after a few hundreds of hours of using just exactly what you need to psychologycally train yourself for that.

i may recommend non-introductory books as well but they require a prior basic knowlege to understand all differences between conductor, dielectric and semiconductor.