[Spirit]

Let's say you buy a brand new DAC and play it out of the box.
Opinions please:
1:  Will the DAC actually sound better after "break-in" time or is this simply an audio myth?
2:  Assuming that one believes in "break-in" being a true occurence, is there some science behind this belief?  What actually happens internally to improve the sound?

[Bill O'Connell]

Electron flow, no matter what component

[Double Ugly]

This video may prove informative.

[PeteG]

Very good video.

Thanks

[TONEPUB]

I liked the part where he said "could hear quite clearly in BLIND tests..."

There is definitely a break in period for most gear and it depends on the
parts used.  If you ever have the luxury of getting two brand new components
of the same type, play one for 300 hours and leave one in the box.

After 300 hours compare A to B and I guarantee that they will sound different,
with the new component sounding a bit more harsh in the high end.

Some products only take 25-50 hours to reach their ultimate sound, while my
experience with products using a lot of Teflon capacitors tend to take longer,
in the 300-500 hour level to sound as good as they can.

Some mfrs also put anywhere from 10-100 hours on their products before they
ship them, so you don't have to deal with it as much.

I know the large manufacturer that they talk about in this video, and they
have also gone as far as to do very high resolution electron microsope
photography of dialectric materials.  After longer periods of time, you can see
how the electrons flowing through the dialectric material actually burn in a path,
much like a walking trail and this tends to change after a long period of time.

So it is actually a bit of a mechanical break in as well....

[face]

There was hardly any break/burn in with the Claritycap MR's compared to other caps I've tried. 

[opaqueice]

This video may prove informative.

Interesting...  but what's the relevance for break-in?  I didn't watch the whole thing, but it seemed to be about comparing two different capacitors, not the same one broken in.

Personally, I'm certain I'm susceptible to "brain break-in", in the sense that as time goes on I adjust to the sound I'm hearing.  The same thing will sound very different from day to day, or even from hour to hour.  So I would never be able to say for sure that some component is breaking in.

[lazydays]

I've noticed a vast difference in the first 400 hours with my monoblocs. Maybe a difference in the first 60 hours on my preamp. I did hear a little difference after about twenty hours on my turn table. And a bunch of difference in my speakers after about a hundred fifty hours. I could tell little difference in any of my CD players or tape decks. I do think I hear differences more with tubes than I do with transistors
gary

[Wayner]

I would have to say that at the atomic level, all compounds start to breakdown as soon as they are formed, especially things that have extra electricity flowing thru them. We see all kinds of things around us slowly break down in many ways. Iron rusts, aluminum oxides and copper turns green (oxidation as well). I guess it could be said that everything has a half life. As far as crystalline structure changing after it is formed, I think we can say "yes", because it is in the slow process of decay. Even the wires connecting your outlet to your stereo have corroded already. Ozone deteriorates things as does the sun, water, chemicals in the air and stuff like that. If there is an improvement, I think it's mechanical in nature like a speaker or stylus cantilever on a phono cartridge.

Wayner

[Double Ugly]

Interesting...  but what's the relevance for break-in?  I didn't watch the whole thing, but it seemed to be about comparing two different capacitors, not the same one broken in.

Maybe you should watch the entire video.

IMO, it brings to light some reasons people hear differences.  It proves there are scientifically quantifiable reasons for things happening/changing which were never measured before.

Point being, it's only one aspect of what I believe are a slew of "happenings" which have not yet been positively identified, and consequently have never been measured.

Personally, I'm certain I'm susceptible to "brain break-in", in the sense that as time goes on I adjust to the sound I'm hearing.  The same thing will sound very different from day to day, or even from hour to hour.  So I would never be able to say for sure that some component is breaking in.

One reason your position and mine will likely continue to be starkly contrasted.

I've avoided cables in my system for as much as a week at a time during a "break-in" period.  The sound hadn't changed after week one (it was still bad), but at around the 10-12 day point I checked again and virtually everything about the sound had changed for the better.  Thereafter the sound never changed appreciably, and I continued using the cables until I found something better (at half the price) 2+ years later.

[Niteshade]

I certainly hope electronic components do not change their written, tested values within a few hundred hours of being energized. I have never read on the side of a capacitor: 100uf for ONLY 200 hours. Or a resistor: 1K for 500 hours and so on. I agree that tubes may change a little in 100-500 hours, but I would hope it wouldn't be that noticeable. Dramatic changes in short periods of time signify to me that there's issues somewhere: Unstable circuit, design flaws, defective components, etc...

Anything mechanical will have a break-in period. Moving parts will change their parameters during an initial time period and should not change much after that.

The most dramatic changes will be with the owner becoming acclimated to their new equipment. A fact: You have to get used to new equipment. Your perception of it will change with time. Hopefully you'll like it more as time goes by.

[face]

I certainly hope electronic components do not change their written, tested values within a few hundred hours of being energized. I have never read on the side of a capacitor: 100uf for ONLY 200 hours.

It's not the amount of capacitance that's changing, it's other parameters. 
Another example of this is how two different brand 10uf capacitors can sound vastly different.

[TONEPUB]

As I said, rather than arguing and pontificating, get two pieces of identical gear,
preferably one that is full of teflon capacitors.

Run one for 500 hours and then compare it side by side to the one that sat in
a box for 500 hours. You will hear a dramatic difference between the two.

It has nothing to do with unstable circuits, design flaws, etc.  And it has
nothing to do with "getting used to the equipment".

Not all components take this long.  But for some reason the teflon stuff
takes a long time to get to where its final sound is.  Wire, resistors, etc
not that much.

[Double Ugly]

It has nothing to do with unstable circuits, design flaws, etc.  And it has
nothing to do with "getting used to the equipment".

Not all components take this long.  But for some reason the teflon stuff
takes a long time to get to where its final sound is.  Wire, resistors, etc
not that much.

I agree.

[opaqueice]

IMO, it brings to light some reasons people hear differences.  It proves there are scientifically quantifiable reasons for things happening/changing which were never measured before.

Point being, it's only one aspect of what I believe are a slew of "happenings" which have not yet been positively identified, and consequently have never been measured.

Hmm.  To me, that's not a very useful way to think about things.  I mean, lots of people report all kinds of stuff anecdotally, from UFOs to ghosts to alien probes.  Occasionally there's really something to it, but most of the time it's just the brain getting a little too much out of the senses.  So the way I see it, we have to make sure there's really an effect first, and only then spend much time trying to figure out what it is.  I'm a scientist by profession (a physicist), and I have to be pretty careful in my work to choose problems that are pretty likely to lead somewhere.  Maybe that makes me especially skeptical about these things - and it also means I have a decent intuition about what kinds of things to expect from electronics, and what the limits of human perception are.

In that video the guy says they found an effect they were sure was audible from blind tests, and then they correlated it with a measurement.  That's exactly the right way to go about it (although given that they're a manufacturer I'm skeptical about that particular effect).  Personally, until I see something like that for break-in (especially of solid-state electronics) I'm just not going to buy into it. 

TONEPUB's suggestion is perfect - try a proper blind test between two or three otherwise identical pieces of gear, and see what it turns up.

[Double Ugly]

IMO, it brings to light some reasons people hear differences.  It proves there are scientifically quantifiable reasons for things happening/changing which were never measured before.

Point being, it's only one aspect of what I believe are a slew of "happenings" which have not yet been positively identified, and consequently have never been measured.

Hmm.  To me, that's not a very useful way to think about things.  I mean, lots of people report all kinds of stuff anecdotally, from UFOs to ghosts to alien probes.

And the usual "objectivist" tact quickly comes into play; compare other's experiences to something absurd, effectively promoting the superiority of their position while ridiculing the opposing position via the comparison.

I've stated my position and have nothing more to offer.  If those who wish to continue can manage to state their respective assertions, beliefs and experiences without belittling or otherwise demeaning others, the thread will be allowed to remain.  As soon as it turns into a pissing contest, it will join all the contentious threads which came before in the Intergalactic Wastebin.

It's inevitable IME, but I remain ever hopeful.

[opaqueice]

And the usual "objectivist" tact quickly comes into play; compare other's experiences to something absurd, effectively promoting the superiority of their position while ridiculing the opposing position via the comparison.

Touchy, touchy!  The OP asked whether break-in was real or imagined, and I gave my opinion.  I didn't mean to ridicule anybody - I perceive things that aren't really there all the time.  If I didn't I wouldn't be human, and for me it's a fact of life, not something to be ashamed of or mocked.

I've stated my position and have nothing more to offer.  If those who wish to continue can manage to state their respective assertions, beliefs and experiences without belittling or otherwise demeaning others, the thread will be allowed to remain.  As soon as it turns into a pissing contest, it will join all the contentious threads which came before in the Intergalactic Wastebin.

 I'm not interested in that old debate either - it's really, really, really boring, and I have better things to do with my time.  The OP asked a perfectly reasonable question, and I've given my take on it.  You, or anyone else reading this, can do and think just exactly as you please.  If I offended anyone, it was inadvertent and I apologize.

[TONEPUB]

I agree with DU...

Seriously, I always thought the break in thing was a little squirrelly myself
and I always THOUGHT I was hearing some differences, but once I took two
pieces of brand new gear, ran one for about 400 hours and left the other one
in the box, it was night and day.  Everyone I did the test for, picked the difference
between the two immediately.

Fortunately, because I do this every day, it only took about a month to put
400 hours on something.

We had the same results with a ModWright phono preamp.  One of our staff
members wanted one, and mine had about 500 hours on it and we compared
the fresh, in the box one to mine.  Everything else was the same and you
could hear a very big diff between the two.

Where this is probably tough and somewhat annoying for a lot of you is that
you don't get to listen to your system 12 hours a day.  Because of that, the
break in process can often seem tiring at best and annoying at worst.  Our
recent readers survey says that the average reader listens to their system
five hours a week....

When you add the fact that it probably takes an hour or two for most
systems to even warm up, this can be a real pain to try and discern.

[PSP]

It would be interesting--for this discussion here--to focus only on our own personal experiences.  There's no point talking about theory (the theory of electrons in real metals with real grain structure is probably not complete, and psycho-acoustics is in its infancy), and there is no point talking about someone else's experience.     

So, after you have bought a new piece of equipment (or put in a new cap, etc.) you either noticed a break-in period or you did not.  For those who do not experience break-in, how many new pieces of equipment (or new modifications to your gear, especially caps) have you installed in the last few years?

In my case, I have often forgotten to think about break-in when installing new equipment, been disappointed, and then relieved as the sound began to improve over a period of a week or two (and sometimes a lot longer).  In the most recent case (nine months ago), a new Denon CDP at first sounded a bit screechy and then went to "a bit too recessed" over the first two weeks.  I refuse to believe that my brain got used to "screechy" and that it compensated by going to "too recessed"... the "it's all in your head" theory would predict that almost every endpoint would equal "it sounds just right".  That's not my experience... sometimes equipment (or more often modifications) end up just sounding bad.
 
Peter

[opaqueice]

There's no point talking about theory (the theory of electrons in real metals with real grain structure is probably not complete, and psycho-acoustics is in its infancy)

I have a book on my bookshelf first published in the 1870's that discusses psychoacoustics, and even refers to previous results.  More than 130 years is a bit old for an infant  . 

My personal opinion is that scientists have quite a decent grasp on what's audible and what isn't (not that there can't be surprises still).  The best way to decide for yourself is to read the literature a little, or even run a few experiments with ABX tests (very easy to do if you have a PC-based sound system).  As for electrons in metals I disagree even more strongly, but I don't think that's going to be a fruitful debate to have here.

So, after you have bought a new piece of equipment (or put in a new cap, etc.) you either noticed a break-in period or you did not. 

I've noticed it every time.  Thing is, I also notice it every time I make any kind of tweak to my system, and even sometimes when I don't.  I've experimented lots with digital room correction software (which really does make a major difference), and it's very interesting how my perception of the effects changes over time after I've switched to a new filter, or turned it off after having used it for a while.  At least in that case, given that all of that processing is happening in software, it's just about impossible for there to be any kind of break-in effect outside my head.