Is there a clear and logical scientific reason why components work better Whe. 'burned in' and does this mean they deteriorate from optimal state shortly after having been burned in?
Do components work better when burned in?
Burning in works because after a time, excluding the first hour electronics are turned on when they are new or the first five minutes after that when turned on from cold ambient temperature; and 24 hours for a new speaker to get used to moving the physical cones and their surrounds, the listener gets used to what their system sounds like.
The listener is by far the greatest variable in the system.
Is there a clear and logical scientific reason why components work better Whe. 'burned in' and does this mean they deteriorate from optimal state shortly after having been burned in?
(...) For example, I stole the pictures below from one of the many threads at diyaudio, on capacitor burn-in (off the shelf, one day, two days) http://www.diyaudio.com/forums/parts/81355-capacitor-burn-break.html
The subject of burn-in is deep, but here's a short and shallow summary. Electrical components will undergo permanent physical changes when voltage is applied to them and current flows, and this is a measurable effect. For example, I stole the pictures below from one of the many threads at diyaudio, on capacitor burn-in (off the shelf, one day, two days) http://www.diyaudio.com/forums/parts/81355-capacitor-burn-break.html
The same applies to warm-up, as the components settle when their temperature rises. For example, in amplifiers, the bias currents will settle; in loudspeakers, the voice coils will also change behavior (even worse here, they may deteriorate as the temperature rises even further than normal - simply put, their electrical characteristics change), etc.
The other side of burn-in is to catch early failures. Because of the effects of burn-in, any precise adjustments must follow that process, for best performance. Unfortunately, very few manufacturers do that, and it's disappointing. To give you a concrete personal example, when I got my XP-25 phono years ago, I sent it back within 10 days for re-adjustment. As the days went by, clearly the gain in one channel was higher, and clearly, the bass was ever so slightly different between the channels. Pass adjusted and sent it back at no charge.
Break-in is a phenomenon with dielectrics and speaker drivers.
Speaker drivers:
The surrounds are pliable, but until after are "worked", they become even more pliable. Sitting for long periods of time without usage stiffens these, so they need to be broken-in again, even older speakers. Also, shipping to shows subjects the drivers to changes in temperature and humidity, which can result in stiffening and the need for break-in again.
Electronics:
The dielectrics in circuit boards, cables and capacitors needs to "Form" when they are new. This process changes the molecular structure similar to the way the annealing changes the structure of metals or the right kind of light can change the energy level of some polymers. The Forming process applies electrical "stress" to the dielectric with voltage and current. Electrolytic capacitors have chemistry also that needs to form when they are new or have sit on the shelf for a long time.
When electronics is shipped, changes in temperature and humidity can cause static charge to build-up in dielectrics, so they need to be "worked" again to dissipate/drain this charge. Electrolytic caps may change chemistry, so they need to form again. This is why even older electronics needs break-in when setting up at shows. The last day of the show is usually the best as a result.
Steve N.
Empirical Audio
+1
Part of that book.
Burn-in is a well documented process used during manufacturing for increasing reliability of some components. The physical changes in electronic components during the first tens or hundreds of hours are known, the only question is if they produce audible effects. As usual, the main question is on these thresholds and how we establish them - and here we do not have scientific answers.
. . .
Break-in is a phenomenon with dielectrics and speaker drivers.
Speaker drivers:
The surrounds are pliable, but until after are "worked", they become even more pliable. Sitting for long periods of time without usage stiffens these, so they need to be broken-in again, even older speakers. Also, shipping to shows subjects the drivers to changes in temperature and humidity, which can result in stiffening and the need for break-in again.
Electronics:
The dielectrics in circuit boards, cables and capacitors needs to "Form" when they are new. This process changes the molecular structure similar to the way the annealing changes the structure of metals or the right kind of light can change the energy level of some polymers. The Forming process applies electrical "stress" to the dielectric with voltage and current. Electrolytic capacitors have chemistry also that needs to form when they are new or have sit on the shelf for a long time.
When electronics is shipped, changes in temperature and humidity can cause static charge to build-up in dielectrics, so they need to be "worked" again to dissipate/drain this charge. Electrolytic caps may change chemistry, so they need to form again. This is why even older electronics needs break-in when setting up at shows. The last day of the show is usually the best as a result.
This is all fine but, the issue remains: Is any of it audible and can audibility be demonstrated under controlled conditions?
This is all fine but, the issue remains: Is any of it audible and can audibility be demonstrated under controlled conditions?
This is all fine but, the issue remains: Is any of it audible and can audibility be demonstrated under controlled conditions?
That is why we are stuck. You are right about the futility of changing most people's opinions but my criteria are pretty clear.I'm certainly not claiming this is definitive, but it is about what I expected and points to the fact a more in-depth test is warranted. I may do so one day, but I see very little benefit to doing all that work! I don't really care anymore if people want to believe in whatever, and the fact is presenting proof rarely results in people changing their opinion anyways.
Sure but that indicates that the test is refutable and inadequate.Those who don't believe will simply claim the test is not valid and then we'll argue about that.
This is all fine but, the issue remains: 1. Is any of it audible and 2. can audibility be demonstrated under controlled conditions?
Sure but that indicates that the test is refutable and inadequate.
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