Burn in for fresh builds?

Or buy really expensive amplifiers dirt cheap at
a pawn shop.
Since they are " pre" burned.

One of my Guilty or not so guilty
laughable pleasures.
Since I am located next to a high gambling area
and local shops are well stocked.

But 2 to 6 weeks no problem.
I stream Jazz 24-7
and go hard with electronic for
at least 3 hrs

my poor little technics is cranked right now

Overbiased class A/B is out of the question
for my listening levels and average temp.
 
...

On the other hand, the same thing will probably happen for resistors, diodes, or whatever, or not?
Resistors, diodes, inductors, etc., are solid material devices. Those materials do not change in any substantial way over time.

Some capacitors, particularly large electrolytics, are filled with various types of liquid pastes. Those materials dry out over time. Some dry out faster than others and good quality capacitors can last for many years. Cheaper ones probably not as long.
 
I believe and I am even concinced that amps and preamps ( solid state and Tubes) really need burn in.
This is my experience.
In 40 years of hi-fi and high end I have had many amps and preamps (new and self made) and I have allways noticed a better sound quality after at least 50 hours of music.
Just consider the burn in time of electrolityc capacitors that is something well known, but even resistors, wires and cables need time.
Besides electrolityc capacitors even all the other components change after burn in.
Why?
I really don't understand the reasons but it how it is.
All the best and good music.
 
...

If everyone (except for a few who cannot hear differences or cannot verbalize "audible difference", or even some who are partout against objectivity, or majority) hears a difference, it is objective.
If all participants who hear a difference describe it in the same way, categorize it in the same way, such as trial 1 = black or trial 2 = grey, it is objective.
If half of the participants prefer trial 1, black, and the other half prefer trial 2, gray, then it is subjective.

...
Your third sentence is in direct contradiction with the first sentence. So, this makes no sense.
 
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At this point we can consider the fact objective.
No. You can consider it an opinion held by you and your friends.

Humans are not rational critters. Especially not when in groups. Conformity comes into play. Have a look at Asch's conformity experiment from the 1950s. Philip Zimbado describes it well here and shows some or the original footage from the experiments:

Tom
 
Also: What happened to statistical analysis? There are statistical methods for analyzing the results of experiments with few participants. The Wilcoxon Ranked Sum comes to mind.

Arbitrarily deciding that if a majority hears a difference then there is a difference wouldn't fly in the scientific world.

Ideally you'd get at least 20 people together as you can then use the statistical methods that assume normality (so says the central limits theorem). That does make life easier in some respects.

Tom
 
If you cannot hear hear the difference after burn in or you don't believe in it I will not try to convince you or anybody else.
What method do you use to determine that the equipment is changing (why does it never get worse after burn-in?) rather than your ears getting used to the new sound, and how do you quantitatively evaluate the 'improvement' after 50 hours without recent comparison to a pre-burn in control listening test?
 
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If you cannot hear hear the difference after burn in or you don't believe in it I will not try to convince you or anybody else.
Cheers
The problem with your posting is this:

"Me and my friends have done together many listening tests over the years and we all allways heard the same imprvements after burn in.
At this point we can consider the fact objective."

No, I'm sorry but there is no way that what you and your friends think you have heard over the years can be considered as objective. It is clearly and entirely subjective.
You claiming it be objective does not change the reality.
 
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Even several good manufacturers claim that electronics need burn in.
Of course they do. The more people are exposed to something, the more they tend to like it. That's called the mere exposure effect. So by claiming that "maybe" the equipment just need to burn in for a little bit, the manufacturers increase the odds that you'll get over your initial buyer's remorse and like the equipment more. The manufacturer will have fewer returns that way, which increases their profits.

Tom
 
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If someone goes to the doctor with a stomach ache and the doctor orders every test known to man, and they all come back stone cold normal. Does this mean that someone doesn't have a stomach ache? No, it just shows that we don't know every aspect of human biology. We keep learning new things about human biologi/medicine and developing new instruments to help us study and diagnose it. Why would electrical engineering/science be any different? The notion that something that can't be measured doesn't exist is just plain wrong and if we all submitted to this kind of thinking, maybe the ruler would be our most sophisticated instrument.

Now, if you cannot hear and/or measure burn-in or whatever we should call, no problem. Don't run around telling the rest of us what we can or can't hear. We would never question your "stomach ache".
 
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You're missing several key points. The biggest one is that I'm not claiming that people do not perceive a difference after burn-in. I just doubt the perceived difference is due to a change in the stimulus that reached their ears. I'm just inviting people to think about all the other explanations for the perceived difference that should also be considered.

I'm also inviting people to apply more science before calling something a fact.

Tom
 
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Can someone with a distortion analyzer of any kind simply baseline their next fresh build ( without recycled parts ), take incremental measurements thereafter, and share the results pllleeeassseeeeee.

While it’s fascinating to see that some manufacturers direct resources at burn in for reasons beyond reliability they’re also businessmen catering to a paying clientele. Some of whom believe in burn in.

🙂