The whole point of good electronics design is to produce a finished product whose parameters do not change over time (and that includes their "sound"). If there are changes, this is a defect in the design. Electronics design is all about stable circuit conditions - designers use all available means to insure that the design will not change over time. In addition, unlike a mechanical object where things like wear can be accounted for and taken into consideration, component tolerance change in electronics is by it's nature unpredictible - that is why designers (at least the good ones) go to great lengths to implement design practices that will result in a stable circuit.

In solid state gear, and especially very recent designs, the compoents that have any potential of change (like discrete resistors, and capacitors) are in the minority - if you look inside something like the 950, the vast majority of circuitry is composed of integrated circuits, and these do not "change" over time unless subjected to stresses beyond their limits.

In the days of tubes, there were an abundance of components, starting with the tubes themselves, that did change over time - they wore out as the emissive material on the cathode of the tube was used. In early solid state designs that used discrete transistors, there were still components like resistors and capacitors that had DC voltages across them - and this could cause small circuit parameter changes. However, in the good designs, design techniques like negative feedback assured that the circuit remained stable over time.

When I designed equipment for testing audio circuits and assemblies for Altec Lansing, I sure as heck made sure that my designs were stable!!

Unless you do some controlled experiments with new verses "broken-in" units, going by memory of what something sounded like is completely unreliable. Do you base your impressions of the sound of "broken in" equipment with identical speakers before and after break in? Did you use the speakers at all between the time the equipment was new and "broken in"? Speakers, being electro-mechanical objects certainly do break-in, especially from the time they are new until they have many hours of use on them. The suspensions (outer and the "spider") change their characteristics with use and the resonant frequency usually lowers over time. The magnets in speakers gradually loose their charge over time, and this causes both output and frequency response changes with use. Unless you take a brand new specimen of a component and one that is heavily used - "broken in" - and directly compare them at the same time using identical outboard equipment, there is no way to tell whether any changes have taken place with regards to sound quality (BTW, I have done this experiment with new verses used examples of the same component while working for equipment manufacturers). Unless you do objective measurements to confirm the existance or non existance of circuit parameter changes there is no way to accurately say that there are any changes that have taken place.

Audio equipment is not voodoo. Designing electronics gear is not like making wine where there are subjective and "mystical" elements to take into consideration. There are no mysterious parameters of the circuit that can cause magical changes in the sound - if there are sound changes, there is something in the circuit that has changed, and this can be quantified.

Of course, if you think you hear differences, then nothing I say will convince you otherwise.

One final thought - why should "breaking in" equipment always result in "better" sound - unless that result is expected before hand? If there was such a thing as "break in", don't you think that over time it would result in a degredation in sound quality, like mechanical and electro mechanical objects degrade over time? Why should electronic audio equipment be so special that it "improves" over time, like a grand piano or violin?

[This message has been edited by soundhound (edited April 03, 2004).]