[c0mfortably_numb]

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Originally Posted by Sovkiller /img/forum/go_quote.gif What exactly burn in does? I mean that many of us believe in it, but I wouldl ike a more scientific explanation

Here is an article from Wikipedia on Burn in

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Originally Posted by Sovkiller /img/forum/go_quote.gif I have heard that the caps need time for fully charge, and settle the flow, specially big ones, but after being 6 month in the self not sure if the cap will still be charged and if still will retain the state they obtain during the burn in....and about the other parameters I'm not sure neither to what extend they really need time to settle, probably they will change overtime with the heat, flow of current etc...but that will haoppen everytime you use them, but not just for using them 200 hours and keeping them in e shelf after...any other ideas???

I'm sure after a few months the caps would loose allot of there charge, but I don't think there would a be a break in period again per-se, someone else more knowledgeable on this please correct me if I am wrong.

 

[Sovkiller]

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Originally Posted by c0mfortably_numb /img/forum/go_quote.gif Here is an article from Wikipedia on Burn in I'm sure after a few months the caps would loose allot of there charge, but I don't think there would a be a break in period again per-se, someone else more knowledgeable on this please correct me if I am wrong.

The wikipedia article does not explain the audiophile benefits of the burn in, I know that all manufacturers test the amps for some time before releasing them to the public, that will avoid further returns, problems, due to parts failures, etc...But that doesn't explain why after some use those amps are claimed to sound better...IMHE after the amp if turn on, and settle for 30 minutes (or even less) and all parts get the optimal working parameters, there is not more changes in the sound, at least not measurable, not sure if at the audiophile level will be, if all components are working properly of course...any more knowledgeable opinion? But please based on facts and with a scientific explanation, in other words, I believe in burn in becasue "I heard" this and that, that nobody can corroborate, or that could lead to a discussion due the lack of evidence are ruled out, for me at least, if there is scientific explanation behind...I would like to know what others think of the burn in in amps???

 

[nikongod]

it is my humble opinion that the burn-in of an amp is very conditional on parts.

some parts burn in more than others. some parts when not used will "un-burn" and require burning in again.

crazyness, eeh?

 

[IPodPJ]

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Originally Posted by Sovkiller /img/forum/go_quote.gif The wikipedia article does not explain the audiophile benefits of the burn in, I know that all manufacturers test the amps for some time before releasing them to the public, that will avoid further returns, problems, due to parts failures, etc...But that doesn't explain why after some use those amps are claimed to sound better...IMHE after the amp if turn on, and settle for 30 minutes (or even less) and all parts get the optimal working parameters, there is not more changes in the sound, at least not measurable, not sure if at the audiophile level will be, if all components are working properly of course...any more knowledgeable opinion? But please based on facts and with a scientific explanation, in other words, I believe in burn in becasue "I heard" this and that, that nobody can corroborate, or that could lead to a discussion due the lack of evidence are ruled out, for me at least, if there is scientific explanation behind...I would like to know what others think of the burn in in amps???

Yeah, I never really understood the concept of electronics burn-in either. With headphones, it's one thing. The rubber or whatever material surround used around the diaphragm, as in a speaker, can loosen up and sound better over time. But that may also be the way the maufacturer intended it to sound after it burned in. I remember in my car audio system, my Dynaudio speakers were claimed to require about 400 hours of burn-in time. And after about 400 hours or so, give or take some, they honestly sounded completely different, and MUCH more dynamic and livelier. But that was also told to me by someone who works at Dynaudio, and who knows their components very well.

With amps and cables, I'm not so sure I would really buy into this theory so much. I guess with tube amps it's perhaps true, but with solid state electronics I just don't see the flow of electrons getting better with burn-in time... if anything, I would expect them to get worse. After wires and silicon chips get hot, they degrade and break down over time. No electronic component will last forever (at least none that I've ever heard of). Sure, any part of a unit can be replaced or restored, but an entire unit itself lasting some ungodly length of time is rather impractical. I certainly don't expect any interconnect or solid state amp I buy to ever have any burn-in benefit, but I will expect it to get worse over time as the electronics get heated and used until their life is exhausted. Maybe being new to the audiophile I'm being ignorant here, but when I hear talk of cable burn in especially, it just makes me laugh. I would bet the only thing burning-in is your ears as you are getting more used to the sound your headphones produce with that particular piece of equipment. Until I see any scientific evidence to back up the fact that cables or solid state electronics are subject to benefit with burn-in time, I refuse to believe it.

 

[Sovkiller]

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Originally Posted by nikongod /img/forum/go_quote.gif it is my humble opinion that the burn-in of an amp is very conditional on parts. some parts burn in more than others. some parts when not used will "un-burn" and require burning in again. crazyness, eeh?

That makes more logic to me that the "eternal burn in", in which anything in physically changed inside the parts, IMO if it is real, once you stock the amps and let the parts rest, you are exposed to the same initial problems with the exception of the failure of course...

 

[recephasan]

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Originally Posted by smeggy /img/forum/go_quote.gif Given how much stuff gets returned, I'm always astonished how little b-stock/refurb is available. Look at any number of sites and you'd be hard pressed to find any mention of it. Just read Head-Fi for a couple of days and you see a number of posts mentioning items having been returned. Makes you wonder...

My Senn HD600 is B-stock, and it had gotten returned for a connector problem.
I checked with the factory and they told me B-stock Senns get the hermetic parts replaced (headband, pads) and the headphone gets checked.

If it gets sent back to a dealer, however, nothing gets replaced.

 

[PinkFloyd]

If, and it's a big if I was ever in the market for a shop bought amp I think I would actually prefer one that had a few hours on it. A component is most likely to fail during the first few days of operation which is why "brand new" is always a touch and go time.... you using the amp is effectively testing and ensuring all the parts are good to go. Years ago some manufacturers used to soak test their amps prior to passing them, Soak testing involved operating the amp in a room (a large oven) and subjected the parts to heat way above their working limits. If the equipment passed this rigourous 48 hour test then it got a "passed" sticker put on it, if it didn't pass the test the equipment was tested, repaired and then put through the soak test again... kept going through until it did pass.

These days amps are generally built and shipped and don't go through these rigourous (time consuming / costly) tests so any failures will take place in your home and, usually, within the first few days of operation. So, cutting a long story short, it's sometimes better to buy an amp that has a few hours on it as you know it's not going to fail.... I think some people may have called a soak test "burn in" and it's not the same "burn in" that people waffle on about here either...... soak testing (burn in) stresses the components beyond their tolerances and if they pass they're good to go......................

 

[Happy Camper]

IMHO- the electrical cir. gets it's largest path developed initially. Not every wire gets the same amount of current. Wire strands will not conduct equally. Not every solder joint conducts through 100% of the material. (path of least resistance) That device will conduct to its fullest with initial use being constant. If not used over time, the path will deteriorate or not be as open to current flow. The process would need to be done again. Each time operating with increased impedance. I would think a component used continiously will sound better than a seldom used one. So if the unit is used for a short period, then put on the shelf, it would not develop as good a sound as one that can be put through a full break in time.

I question whether high current burn in or low current burn in is best to start the life cycle. Do you turn the volume all the way, or low. For phones, full volume could be dangerous. For electronics, a stronger load would burn thru the most available material in the path. Of course this could all be BS. Would like to hear from the EEs on this.

 

[PinkFloyd]

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Originally Posted by Happy Camper /img/forum/go_quote.gif IMHO- the electrical cir. gets it's largest path developed initially. Not every wire gets the same amount of current. Wire strands will not conduct equally. Not every solder joint conducts through 100% of the material. (path of least resistance) That device will conduct to its fullest with initial use being constant. If not used over time, the path will deteriorate or not be as open to current flow. The process would need to be done again. Each time operating with increased impedance. I would think a component used continiously will sound better than a seldom used one. So if the unit is used for a short period, then put on the shelf, it would not develop as good a sound as one that can be put through a full break in time. I question whether high current burn in or low current burn in is best to start the life cycle. Do you turn the volume all the way, or low. For phones, full volume could be dangerous. For electronics, a stronger load would burn thru the most available material in the path. Of course this could all be BS. Would like to hear from the EEs on this.

It's all about chemicals according to one man here and here the lead free article is particularly interesting.

 

[nikongod]

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Originally Posted by PinkFloyd /img/forum/go_quote.gif These days amps are generally built and shipped and don't go through these rigourous (time consuming / costly) tests so any failures will take place in your home and, usually, within the first few days of operation. So, cutting a long story short, it's sometimes better to buy an amp that has a few hours on it as you know it's not going to fail.... I think some people may have called a soak test "burn in" and it's not the same "burn in" that people waffle on about here either...... soak testing (burn in) stresses the components beyond their tolerances and if they pass they're good to go......................

yes, when a failure happens it will likely be in the inital ownership stages.

BUT with newer design and materials (big emphasis on materials, ever see a cap from 1980 stamped 85/105*c?) failures are wayy less likely with newer parts.