Just a question about the discussion. SH, when you refer to "Industrial Equipment" what equipment specifically are you referring to? My first thought here is....maybe one doesn't critically listen to/evaluate "industrial equipment" so maybe subtle changes (break in?) wouldn't really be relavant or examined. Certainly in Audio, when we are all sitting in the quietness of our houses, listening rooms, studio's etc ..subtle changes might be noticed? Certainly not challenging the premise, just trying to understand all the points of view,

I am one of the loony audio geeks that swear I can hear a differnce in electronics as they age...for whatever reason.....and not always for the better. I'm sure it's my ears that deceive me....THOSE HAIRY BASTARDS!

Peace,

S

Actually not. As a scientist my goal is to seek understanding of variables and systems. It is then the goal of engineers to use that knowledge in design applications. Whether certain variables can be compensated for in actuality may depend more on factors such as economics or aesthetics than science. However, that seems a little off topic. It seems that much of our disagreement is about the philiosophy of science itself and the role of paradigm shifts and new ways of looking at the world in science.

FYI, my particular field is quite aways from audio electronics. I am an ecological geneticist and also teach biostatistics.

It is a catch all that includes anything not related to audio. One of the types of electronics I have designed was test equipment that tested audio circuitry (at Altec Lansing). This type of circuitry obviously must be a stable as possible, yet it uses the many of the same types of circuits and parts as the audio equipment in the home. Knowing what types of parts and circuits are subject to changes and which aren't is very important in this types of design, and knowing what to do about it.

Yes......and they do compensate. Truthfully, audio is such a basic (and old) type of disipline that it is very simple and a matter of course that potential problems from drift would be compensated for. No magic here. Maybe in very advanced circuitry well beyond the scope of audio using technologies that haven't been around for decades, but not audio. You can argue "what-if's" forever, but at some point reality sets in.

The disagreement is not on some theoretical or academic level - it is on boring 'ol rubber-meets-the-road practical engineering that is routinely performed, day in and day out. Your field is a bit far removed from designing audio equipment, and it is probably less mature, more complex and less well understood.

i think this topic has exhausted all interest on "break-in".

Who asked you? Go back to your room.

I agree completely.

Well said and I also agree completely :p

I'm not sure if it's theoretically possible, but the explanation I've heard from at least one high-end audio company is that their components need some time to break in because it takes time for all of the capacitors to fully charge. This at least seems scientifically explainable. Not sure if capacitors can, themselves, break in (have a higher total capacity after some amount of charging and discharging), but such action might explain an audible effect.

Not an engineer by a long shot--I'm just throwing a theory out there.

The capacitors charging would be part of the warm-up process, not really break-in, as they will charge up every time you turn the unit on or plug it in.

Capacitors that are in the audio path (as opposed to the power supply filter capacitors) can definitely change the sound of a component as they age over time, especially if they have a DC voltage across them as in a blocking capacitor. The problem is that capacitors have not really been used in this way since the widespread use of integrated circuits rather than discrete transistors - in other words at least since the 1970s. Vacuum tube circuits use blocking capacitors which may have hundreds of volts DC across them, and these capacitors can certainly influence the sound. In discrete transistor circuits that use blocking capacitors the DC voltages are much lower, but the capacitors still will change their characteristics over time.

In my tube amplifiers I use this aging effect to in effect "tune" the sound character of the amplifier to match the characteristics of the speakers. The use of oil capacitors in the circuit path is widespread in tube amps as a way to achieve this.

I would certainly say that components manufactured in the 1950s and 60s changed their sound from the time they were new, apart from the aging of vacuum tubes. Whether this would qualify as "break-in" is a matter of perspective.