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Post by Deleted on Jun 1, 2013 10:23:22 GMT
You aggressive chap! You need to do some yoga. I practice Zen! Remember?
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Rabbit
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Post by Rabbit on Jun 1, 2013 10:28:12 GMT
Zen you need to do a little more of it!
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Post by Deleted on Jun 1, 2013 10:34:33 GMT
Zen you need to do a little more of it! ZenTech qualify?
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Rabbit
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Post by Rabbit on Jun 1, 2013 10:45:20 GMT
Translated? 'Then (zen) you need to do a lot more of it!!!
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solderdude
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Post by solderdude on Jun 1, 2013 11:18:26 GMT
Technically, BI is for REAL. You think the car engineers stupid? No they aren't stupid but it is made of lots of parts that are in contact or slide over each other and rotate e.t.c. a lot of components need to 'marry' which takes time just as polishing metals takes time. In headphones there are no friction components and that is a big difference IMO. Also, giant high voltage industrial traffos also need to be run in at lower voltage before the full blast during commisioning. Then the traffo engineers are also stupid? Again a non comparable thing as transformers are not 'run in' but tested for electrical leakage and with low power to see if it starts to 'spark' somewhere. Often they are also oil cooled which makes them 'dangerous' These large transformers literally explode violently when something is wrong with them and connected directly to it's intended voltages/power. So for that reason they slowly increase the voltage for testing. Like wise with EMC testing. We start with low voltages/currents and increase to the maximum needed slowly to avoid damage. It's not that the copper and metal cores need to be run in which would seem to be the analogy for audio components. Polar capacitors that have been left unconnected for years need forming of the electrolytes which is the closest to being run in. Some membranes of drivers or suspension of cones may or may need some 'stretching' to get to the intended operating properties and other materials do not. Self biasing electrostatic headphones also need lots of music before the bias voltage sets (also when being powered up on mains when it has been off for quite some time) One could say 'burn-in' there but it is more that some time is needed for those parts to reach proper operating conditions. I have revived old capacitors in the past and simply monitor the current to see when it is formed. Can take a few seconds to hours depending on age, voltage, capacitance, manufacturer, type.
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Post by Deleted on Jun 1, 2013 11:44:13 GMT
In headphones there are no friction components and that is a big difference IMO. Actually, it makes sense for BI for HP too as the flexing of the spiders and membranes constitute "quite a lot" of friction without oil, isn't it? Car Run-In is with oil and more or less can be written as on a macro scale whereas the HP drivers illustration is on a micro scale. However, in cars we are writting of kW output and HP W+/-. So taking it at their respective scale, the HP BI will affect sound quite noticeably to about the same magnitude as the car as we are writting of similar things at their respective scale. Just like for DAC, the lesser the voltage the more important will the effect be on the DAC from PS. Whether we can hear it, that's another perspective altogather. That's always the "death penalty" for both objectivists and subjectivists to write on as we are writting 2 entirely different things. Again a non comparable thing as transformers are not 'run in' but tested for electrical leakage and with low power to see if it starts to 'spark' somewhere. Often they are also oil cooled which makes them 'dangerous' These large transformers literally explode violently when something is wrong with them and connected directly to it's intended voltages/power. So for that reason they slowly increase the voltage for testing. Like wise with EMC testing. We start with low voltages/currents and increase to the maximum needed slowly to avoid damage. It's not that the copper and metal cores need to be run in which would seem to be the analogy for audio components. Yup, they can explode when things go wrong. However, they will also spoilt much faster if the traffo goes in at full blast even when nothing happen as the copper and all those cooling oil tubes need temp to form or anneal or sit properly in their casing. Traffo noise? Where it comes from? From improper sitting, right? It's always run-in at low voltage for maybe a day or 2 and then full blast for another day or 2 depending on safety requirements of each country. I think it's a requirement for commissioning to meet safety laws whether we like it or not.
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Post by madmac on Oct 13, 2013 17:55:56 GMT
I don't believe that we're able to hear burn in. Untill now the effect has not been proven and differences are tiny. I see it this way: if it were be true that a DT770 needs 200 hours of burn in to perform at it's best, the factory would do this in the production process to be able to sell phones who sound at their best when they are taken out of the box.
Compare it with Eibach lowering springs for cars. Eibach puts them in a machine and squeezes them thousands of times to be shure they won't drop further when they're allready on the car.
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Rabbit
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Post by Rabbit on Oct 14, 2013 16:18:04 GMT
I've only heard it for real, once. A Superlux that had no bass and 30 minutes later, it appeared. Frans had the same with one of his.
However, if I'm honest, I have found most to be pretty stable.
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Post by Deleted on Oct 14, 2013 18:33:34 GMT
i remember buying a £30 toslink cable from an AV shop in maidenhead a few years back. as i was about to hand over my debit card to pay, the guy in the shop said "remember to give it 100 hours of burn in time". my debit card did not reach his hand, and i left the shop without saying a word.
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solderdude
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Post by solderdude on Oct 14, 2013 18:40:22 GMT
LOL... the photons need to break-in the plastic fiber so they travel more easily. After exactly 89 hours (and a few minutes) the photons suddenly stabilise their speed and sound much nicer.
Only heard real break-in with one HD681 quite profoundly and with 2 of them it lasted a minute at the most. Little bass you heard 'coming up' quite fast (in one familiar song).
Never heard it with any other headphone nor was able to measure it though.
If someone talks of hundreds of hours it is more likely brain in or pads complying over time.
Funny thing is I only heard differences in the lowest part of the frequency range, sub-bass to bass and it was short and only with a few of them (percentage wise I think 10%). I never heard differences between all of them in the mids and highs (well the one that had relatively little bass also had slightly less highs). This was the one from Chaz that took about a month to cross the ocean. The rest of them was pretty consistent, even over the years so the various reports of people claiming they get lesh 'hard' sounding over time or having versions that do not have that peak is highly suspect. If that were the case I would have found a dud here and there.
I had one not modified and one modified version at hand so I could compare incoming and outgoing 'goods' with a reference.
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