Physical explanation of amp's break in?

Here's my last post to this thread.

I am not an EE, nor have i ever claimed to be. I will only add that i have almost 2500 posts on this forum and who knows how many at AA. Having said that, there have been less than a handful of those posts that an EE posted something contrary to what i had referenced when talking on strictly technical terms. To take that a step further, some of these disagreements have been due to poor wording on either my part or theirs and we really were in agreement when all was said and done.

As such, one does not have to have a piece of paper to tell you what they know or don't know. On the other hand, having that piece of paper simply means that someone knew enough to respond correctly to specific questions on tests. This does not give them practical experience when trying to design electronic circuitry or deal with real world problems and situations that arise in such circuitry.

My business partner, who does have his degree, has stated many times over that school taught him the basic fundamentals of theory but most of his knowledge of how things operate has come from hands on experience. My personal opinion is that many EE's will share that opinion as they are smart enough to realize that wisdom and knowledge come with experience. Anybody can read books ( as i did ) but applying that knowledge in a real world scenario is what seperates those that have "book knowledge" and those that can solve real world problems. Having said that, I don't know of any College that issues degrees in "common sense", "problem solving" and "application of knowledge". What College degrees do verify is that someone understands the basics of the subject at hand and that the College that issued the degree is willing to put their name behind that fact. What someone does with that basic level of understanding is up to them. Having that piece of paper does not necessarily mean that they know everything that there is to know about the subject at hand. It simply means that they knew enough to graduate. Mind you, one can graduate with an "A" or a "D-" average also.

Other than that, here's a thread on AA that discusses this very subject. An EE and i both come to the same conclusions there, much as what we have done on many, many hundreds and even thousands of threads.

Hasta la vista, baby.... Sean
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http://db.audioasylum.com/cgi/m.pl?forum=general&n=52730&highlight=EE+Sean&r=&session=

After reading a statement like this, "anybody that tells you that components don't break in or 'settle' is either UNEDUCATED [emphasis added] about the subject at hand and throwing out a guess at your expense (IF you believe them ) or knows better and is blatantly lying to you," is it unreasonable to ask the author about his education?

Personally, I wouldn't care if someone never got past grade school if he could reference test measurements or a controlled study to support his argument.

Paulwp, I hope you accept the fact that components do initially shift their values, in predefined tolerance range? You don't have to call it break-in and it doesn't automatically assume any sound improvement. But if the same kind of components will tend to settle in the same direction, and to achieve their natural point of settling after about the same hours of use, where do you see a contradiction that during design period an "already settled" prototype is evaluated and being worked on, so the aim of the designers is not how it sounds just assembled, but after known and measured period, specifically for the parts used?

No, I don't accept it as a fact, not do I deny it. Theories to justify the belief in burn-in are of no interest to me. I can't think of a less interesting subject actually, but I suppose I would pay attention to some test measurements. An amp had better perform to specs when first plugged in by the buyer. Then, so long as it continues to do so, it shouldn't sound different from day one. That's been my personal experience of using amps, though of course, I havent done a controlled analysis.

Take two identical amps. Do a DBT to verify that you can't tell them apart. Break one of them in. Then do a DBT to see if you can tell them apart. Do this with a significant number of listeners or a significant number of times. Come back and tell me the results.

Or, show me some bench test measurements in the range of audibility.

Oh, tube amps may change. I guess it takes tubes a few hours to settle in, and then they start downhill.

But, again, who cares? For me, it's like shoes. Do shoes break in? Of course. Should you go ahead and buy a pair that hurts hoping they will break in the right way? I never do. And I never keep a component that sounds wrong hoping it will break in.

Sim Audio amps all have a notoriously long break-in period, 600 hrs minimum. Also after you power them on from a cold state they take a couple of days to settle in. Look at it from the manufacturer's perspective. If it wasn't true and borne out by experience then why would they state it in their documentation again and again. There is no upside to fabricating something like this.