Physical explanation of amp's break in?

Unsound...We all agree that loudspeakers (and phono pickups) improve with use as the elastomers soften up.
As I mentioned, Taguchi was a disciple of W Edwards Deming, whose genius was not recognized here.

Dmitrydr...If there is a "high end" TV, it's Sony. You pay more for a Sony, and it performs better. But, they don't tweek each unit to make this happen. They tweek the design and the productiuon process so that EVERY unit that comes off the line is superior.

Everyone...How is the weather out your way?

Eldartford, I meant a difference between even very good mass-market product and hi-end. Among TVs I would think about Pioneer in this group, but not Sony. It's not just a matter of "better quality-higher price", it's matter of different markets: I guess under normal circumstances you don't come to Best Buy for your next amp upgrade? If you build a graph Price=F(Quality) on some stage it will go up much faster then before, i.e. a little increment in quality will cost much more money then similar increments before. Here comes audiohile's market. If you don't tweek the product, it'll be declined: as per the same graph, for normal practical approach it's worth to go a little bit down in quality for quite significant difference in price.

I guess it is clear that there is no need for another EE like me to comment on this, however I am about to. The thread has drifted to where it is hard to tell what the latest consensus is but if it matters at all, I think we tend to over-analyze burn-in a lot. I have done lots of research in system reliability (for aircraft systems mostly - they get picky about this sort of thing) and capacitors are by far the biggest problem and change the most. However, I hate to say it but the design uses a given value and not every component is matched when installed in your amp (and it drifts anyway), thereby making burn-in moot for amps and preamps. However, speakers are a different story...but that is for another thread.

As a final note, we don't actually understand everything in the universe, do we?? Some of you sound like you do. Each year I spend in EE courses (I am now at year 8), I realize how little we actually understand well - and that is the part that shouldn't be forgotten. Everything changes, nothing stays put. Arthur

Aball, back to an earlier question: when you say that capacitors drift, for a given type of capacitor, do they always drift in the same direction?

Aball: "However, I hate to say it but the design uses a given value and not every component is matched when installed in your amp (and it drifts anyway), thereby making burn-in moot for amps and preamps."

If i sum up your statement here, it reads as the following to me: "Components are typically not precision matched upon installation and will shift in value over time. Due to the shifting values, measured performance and possibly sonics may vary from the time that you first start using a brand new product till the time that it breaks down and needs repair". Does that sound about right ? If you are in agreement with that "interpretation" of what you said, would you say that most electronic components typically reach a plateau and stabilize in value for a period of time before reaching a point where decay starts to set in ?

Other than that, I agree with two of other points that you made that aren't really open to interpretation. The first one is that caps typically show the widest variance in measured value over time. I will also add that they typically display one of the highest, if the not THE highest, failure rates of any given component. The second point was "the more you know, the more you realize you don't know". I think that this saying is pretty self explanatory. Sean
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