[_scotty_]

denverdoc, I am sorry that my comments were of no help in offering a partial
explanation for the reports of people who say they have experienced the break in phenomenon. It appears to exist and I have experienced it myself
on numerous occasions.  As it relates to cables I have no insight into why I have heard them change over time.
  Steve, I appear to have talked to different loudspeaker designers and electronic
designers than you have, this fact and my own first hand DIY experience
with power supplies and loudspeaker building gives me a different point of view from yours. I have a PDF doc from PartsExpress that discusses
the measurement conditions they used derive a standard deviation
statistic  on the Titanic MKII woofer.  I can email you the doc if you PM me your email address. The pdf is 287KB in size.
Occam ,I have the same complaint about the Panasonic FM caps when used as a coupling cap.They also take a long time to break in, maybe month depending on use. The good thing is that they smoke a BlackGate from the beginning and just get better.

[denverdoc]

No.  Unfortuneately, as audiophiles, we alter what constitutes proof. We oppine endlessly on the minuitia wrought by this or that components change or burn in phenomona, but rarely follow the simpleist of experimental techniques, maitaining a control sample. Rather, we rely on aural memory, and maitain we can recollect subtle differences over periods spanning months. I'm as guilty as anyone and will simply rationalize by saying, I don't have the resouces (or discipline) to incrementally verify differences c ...

Occam, good points as to lack of discipline, and I maintain memory (as in Dali's famous painting titled The persistence of Memory) is an extraordinary fickle and unreliable basis on which to form comparitive impressions, but sadly it is the tool most of us rely on in forming such opinions. To wit, I have a couple pair of different speakers in my listening room. The 2500. pair are not perfect, but for a few reasons, have managed to outlast other speakers of far greater pedigree such as Infinity IRS Beta, Thiel CS 3.6, Dunlavy Sc-IV, Infinity Prelude/MTS, etc. Recently bought a DEQX which took the tiny pair of JBL s26IIBE's from overachiever status to near SOTA transducer (except in bass response). FR was good from 0.05 dB from say 160 to 20K and Phase error was 0 out to about 6kHZ where it began a gentle linear descent. After several days of listening to these, when I put the 2500 pair of speakers back in, they were nigh unlistenable.   That is until they were DEQX'ed. Did they sound the same, not quite as in one is a ribbon based system which loads the room differently and images less distinctly, has bass now flat to 20 Hz etc.

My point is that my audio memory of what was acceptable performance had acclimated over time to the point I was incabaple of hearing fairly serious errors in reproduction.  How this relates to the topic at hand is fairly simple. Memory is not to be trusted over time, and for those of you who take issue, look at the next paragragh and if you are brave enough to try, you will realize how difficult it is to hold a perception for a few seconds to few minutes, so why think weeks to months is more reliable?

I just wish that people with the guts and a good friend would try Blind A-B testing--maybe just a few hours a week for a few weeks with different components. Then perhaps such discussions might be more productive than shouting into the wind,
John

[panomaniac]

I'll jump in here with my 2 cents.
 the terms "Break-in" and "Burn-in" should not be interchanged. "Break-in" should refer to mechanical components (E.G. speaker drivers) and "Burn-in" to electronic components (E.G. semiconductors, caps).

I learned to break-in drivers years ago, but have no proof that it really works. It seems to work, but I've never heard an A-B test.  And in all my years in pro audio, I've rarely heard it mentioned.  Pro drivers would seem to need as much or more break-in than any others.

Burn-in is a term I learned only last year, when I began reading online audio forums and reviews.  Doesn't make sense to me, unless we are talking about electrolytic caps.  In the pro photography world it is common "knowledge" that the big high voltage caps in flash units need to be "formed". It is said the several charge-discharge cycles are needed to bring a new cap up to full potential. The same goes for caps that have been sitting for months or years. True?  I don't know. Maybe there are some tests out there somewhere.

As for the burn-in of semiconductors, wire, connectors; I remain highly skeptical.

[-Richard-]

An interesting thread for many reasons.

There is a certain intoxication surrounding audio...
and perhaps that partially accounts for why it is so habit forming.

The persistent question is WHY?

I suspect that there may be a relationship between our brains
auditory perceptual development...how sound is "decoded"
by the brain and given a "context" within the field of our
experience of what we think of as the real...and our need to
"confirm" a condition of constant "contact" with our environment
through auditory stimulation...

Like the chatter or birds who are really talking to each other
over distances and habitats that make visual contact impossible...

An illustration of this would be to turn the sound off on a film
you are watching that is particularly dense with auditory
cues...suddenly our sense of what is going on has shifted
entirely to the visual and we may feel "detached" from the
emotional context of the narrative...

It is clear that a good portion of our early perceptual development was
based on "sense" patterning...we had to learn to see the patterns
within the intensely dense sensory information of our jungle or
forest habitats in order to pick out the snake coiled on that branch...
or the lion lurking behind the brush...or an enemy tribe...

And that would be just as true for sound...how accurately we could
translate sound would certainly make the difference between a successful
hunt for example...or "sensing" the presence of danger...

In our modern life sense patterning is still is a vital part of our survival...
a walk on the wild side in any major metropolitan city would be more
than enough to convince anyone of its importance...

However, over thousands of years of cultural development, we have
learned to take sense patterning to the level of aesthetics...and all the
arts are based on this fundamental "recognition"...music may be the most
obvious example...

It may well be that the reason many music lovers never fully adapt to
"classical" music’s particular language, especially in small ensemble
works, may have a great deal to do  with the way it constructs its patterning...
which may not be entirely perceived if ones auditory development never
included this form of subtle "recognition"...in other words a "deeper"
listening may be required...less stimulation and more "contact" with
the music’s "interior" language...the same phenomena can be noted
for Jazz for example...

But there is also a deeply satisfying pleasurable response to our auditory sensing.
Music is built around that deep pleasure zone that certain sounds
impart to us...and I suspect that our love affair with audio is bound up,
to a certain extent, with the sheer pleasure we derive from hearing
musical instruments make the particular sounds they do...this may well
be a clue as to why non audio music lovers never "get" the fascination
we have with putting together a "system" that allows the individual
instruments to come alive...

What does all of this have to do with whether or not there are notable
changes in sound as a result of burn in?

denverdoc makes two very important points; first is the often dwindling
excitement we feel after our first impressions upon hearing a new component...
which ultimately sets us up for disappointment and a renewed search for
the next auditory "thrill"...and second is his suggestion that memory is
"...extraordinarily fickle and unreliable..."

I would like to add a third consideration.

That all of our perceptions are based on COMPARISON...

Here is where the devil comes into the picture with regards
to our audio junkie habit...we cannot "know" what anything
sounds like without some form of comparison...we listen to
this or that new component...let us say a speaker...and then we
compare it to the one we have been listening to...and that is where
and when the "thrill" seeps into our soul...but over time, a sustained diet
of this new "thrill" no longer holds our interest...because as soon as it
becomes our resident speaker there is nothing to compare it to...

What I am suggesting here is that the thrill of each new component
is merely based on some form of comparison...without comparison
we would have no way of "judging" the "value" of our audio listening
experience...except of course if we compare it to live music...
but live music has so many variables that it may be impossible to
use that as an “absolute”...

I am speaking of the experience of “sound” alone...I am not talking about
the ability of music to move us into a transcendent zone of feeling which
is another consideration entirely...

As to burn-in affecting the sound of electronic components...it seems
to me that I have noticed changes over time here and there in this or
that...but I no longer trust myself...

As Henri Matisse said, “...precision is not reality...”

Warmest regards to all.

[AphileEarlyAdopter]

I'll jump in here with my 2 cents.
 the terms "Break-in" and "Burn-in" should not be interchanged. "Break-in" should refer to mechanical components (E.G. speaker drivers) and "Burn-in" to electronic components (E.G. semiconductors, caps).

I learned to break-in drivers years ago, but have no proof that it really works. It seems to work, but I've never heard an A-B test.  And in all my years in pro audio, I've rarely heard it mentioned.  Pro drivers would seem to need as much or more break-in than  ...

When you can believe capacitors can change, why not the insulation on the wires ? The insulation on the wires create a capacitance between + and - and the ground.
I initially thought the burn-in might be there for interconnects/speaker cables but not for digital cables. But when I got my Zu Ash, the bass was thumping loud and the highs very harsh.  This was really obvious, now after a month, the cable sounds pretty normal. I A/B'ed it with my Acoustic Zen and the differences are subtle (even though, I still prefer the Zu Ash).
If you believe different types of insulation makes a difference in cables. It may not be a stretch to visualize the insulation's dielectric values changing a bit with continuous current/voltage.

Regarding A/B comparison - I think one needs to do A/B comparison only after listening to particular cable component for a while. Only longer periods register a stronger/better impression in your memory. It also depends on how seriously you listen to the music. To me, the major difference between high-end and consumer hi-fi is soundstage/venue ambience. The next criteria would how good the bass is and the highs are. If you listen to various kinds drums live in close proximity you will know it is very difficult to reproduce with speakers/electronic eqiupment. The better a component makes me think that it is a real drum, the  more I feel it is high-fidelity. Yes, unfortunately, we all have to rely on memory/impressions.  Measurements can support this, but I dont think we know all that is needed to know or atleast how to measure them.

[Occam]

......
Occam ,I have the same complaint about the Panasonic FM caps when used as a coupling cap.They also take a long time to break in, maybe month depending on use. The good thing is that they smoke a BlackGate from the beginning and just get better. ...

Scotty - your response illustrates my point. How would you know that Panny FMs 'smoke' the Black Gates? How do you know either break in rather than the listener simply acclimating?  I'm not disputing your findings (bye the bye, in what specific applications, ps bypass, signal coupling...?) But I'll simply ask if you ran even the simplist of no-blind experiments where you had 2 otherwise identical components, save for a BlacK Gate and Panny FMs in whatever position (an additional 'baseline/contorl' version which could add substantial information would also be nice). Setting aside whatever concerns about experimental design (sighted, metrics, etc...) We, as audiophiles, hold ourselves to rather minimal standards of scientific inquiry. I'm certainly not accusing you of anything I don't do myself, but as an amatatuer, I do audio 'science' in a half assed way. At one time, I actually had the resources and disciplie to do actual research (in other areas) and what I now base my conclusions upon, is embarassing. While I still think I remember the difference between plausible, indicative, compelling, and conclusive, I simply rationalize my poor scientific methodolgy as lack of resources.......

[_scotty_]

Occam,The application is as an output coupling cap in a preamp.  Actually the test was rather simple to do, I modified one channel at a  time and compared a fully broken in 680mfd 35 v BlackGate NX to a green 560 mfd 35 v Panasonic  FM cap. I  put a mono signal through both channels and
switched between channels. The differences were very obvious with the clear winner being the FM cap.  I then proceeded to modify the the other channel.
This was a no brainer and at a $0.61 each a very cost effective mod as well.
Scotty

[Tyson]

Drivers do break in.  If you measure them before and after breakin, you will see that the T/S parameters do measure a bit differently.  It is almost certainly because the spider and driver surrounds loosen up with use.

[Occam]

Scotty - now thats an approach that we should all strive for. Kudos!

[denverdoc]

I suspect that there may be a relationship between our brains
auditory perceptual development...how sound is "decoded"
by the brain and given a "context" within the field of our
experience of what we think of as the real...and our need to
"confirm" a condition of constant "contact" with our environment
 ... would like to add a third consideration.

That all of our perceptions are based on COMPARISON...

Here is where the devil comes into the picture with regards
to our audio junkie habit...we cannot "know" what anything
sounds like without some form of comparison...we listen to
this or that new component...let us say a speaker...and then we
compare it to the one we have been listening to...and that is where
and when the "thrill" seeps into our soul...but over time, a sustained diet
of this new "thrill" no longer holds our interest...because as soon as it
becomes our resident speaker there is nothing to compare it to...

What I am suggesting here is that the thrill of each new component
is merely based on some form of comparison...without comparison
we would have no way of "judging" the "value" of our audio listening
experience...except of course if we compare it to live music...
but live music has so many variables that it may be impossible to
use that as an “absolute”...

Richard,

I couldn't agree more and a while pack posited on a thread that their may be a connection between what we now know about cocaine addiction and audiophilia. W/O going into all the details, that over the career of an addict two interesting phenomena take place--first, that after several exposures, ritualistic and sensory aspects of using light up the brain (in particular areas of the midbrain) in much the way the actual drug does, but that over time, the phenomenon of receptor downregulation makes it nearly impossible to recreate the initial thrill--this is where the chase comes in. In high end audio, the analogous behaviors seem pretty obvious and in part may explain to some extent why a great many music lovers don't mind the hassle of cleaning vinyl whereas my 19 yo daughter would as soon wash the dishes. The endless upgrade path where vast amounts of money and time are devoted to this pursuit often at the expense of other areas of ones life is also diagnostic for an adddictive pursuit.  And as you mention, usually w/in weeks the "thrill is gone," leaving a need to insert yet another change. With the ability to quickly deceive ourselves via the placebo effect, it is no wonder so many times you hear of vast and staggering improvements thru a change that cannot be measured. If the rest of consumerism/technological advancements was as steeped in mysticism as hi-fi, and not based on objective measurement, we'd all be in very sorry shape.

What is most curious again, is that those most inclined to trust their ears as the final arbiter of quality are often the least willing to participate in A/B/X testing which if you really think about it, is both a delicious irony and paradox. Or as the last poster IMO does, clings steadfastly  to some almost related physical phenomenon in the hope that by offering a single counterexample, the whole premise of burn-in and non-measureable differences gains some validity.

This is not analytic in the least, and frankly I would very much doubt the author could ID a shunt capacitor of 10x the delta C that might occur if the insulation properties of cables did somehow change over time--and this in a back to back immediate A/B/X scenario so that one didn't have to contend with the effects of months of time.

This is where we as enlightened consumers can get more value for our money. Try the 1/2 inch face plated megabuck amp vs something from Adcom, Rotel, what have you and with the help of a friend to whom you don't mind knowing your discriminatory limitations, just do a little trial one weekend. Then go down the food chain until you can ID say 80 percent of the time the difference.

Such experiments are endless, and in the end have much more value for all concerned than the endless debate over such topics as burn-in. Probably the best endeavor for any a'phile in the pursuit of truth might be to build his own speakers and try voicing the XO's. Back in the days of yore before high end magazines began handing down edicts from above, there was much more of this type of experimentation and learning going on. Now swapping loudspeaker cables w/o some blind referencing to 10 guage romex house wiring or what haveyou has become a hands on experience.  
John

[denverdoc]

Occam,The application is as an output coupling cap in a preamp.  Actually the test was rather simple to do, I modified one channel at a  time and compared a fully broken in 680mfd 35 v BlackGate NX to a green 560 mfd 35 v Panasonic  FM cap. I  put a mono signal through both channels and
switched between channels. The differences were very obvious with the clear winner being the FM cap.  I then proceeded to modify the the other channel.
This was a no brainer and at a $0.61 each a very cost effective mod as well.
Scotty

Scott,

Close but no cigar. The experiment should have been conducted w/o your knowing which side of the amp was being listened to. I suspect the differences might have vanished like so much smoke, but maybe not--at least we could rule out the expectation factor.
John

[ctviggen]

Now, were three different capacitors used?  That wouldn't prove anything.  You'd have to use the same size and type of capacitor, only break one in and leave one not broken in, then perform a blind test using the two capacitors.

[panomaniac]

When you can believe capacitors can change, why not the insulation on the wires ?

A good point.
But I would want to know just how much the dielectric of the insulation can change, and if that change is audible.  And is it a change for the better?

[_scotty_]

A single blind or double blind test is almost mandatory to differentiate between the real and imagined differences between two similar performing devices.  However  when the magnitude of the difference is large enough
a simpler test will suffice.  It is probably impossible to quantify the magnitude
of the difference that I observed between these two caps within the context of an online discussion.  The differences were not subtle and other people
I am contact with have reported similar results.  As I only had a $1.22 plus shipping in the caps  I did not have expectations of superior performance
based on the cost of the caps.  I have never been one to chase after minutiae in the form of  popular tweaks guaranteed to improve your stereo system and turn apples into oranges.   If the improvement isn't immediately obvious or isn't reliably detected  in a single blind test I don't really want to fool with it.  Fundamental improvements to a circuits design or power supply
seem to me more fertile ground for experimention.  If you have an application where the size and voltage available in the FM series is useable it would seem to be a relatively  inexpensive experiment to see if a an improvement in performance can be had on the cheap.
  On another note off topic to  denverdoc,  I was wondering  how you
implemented the recommended  notch filter in your system. Were you able
to do this electronically or did you use the passive component approach.
Here is a link to an interesting study of the BG 75 performance characteristics.  http://ldsg.snippets.org/ALSR/dbsindex.html
 Scotty

[denverdoc]

When you can believe capacitors can change, why not the insulation on the wires ?

A good point.
But I would want to know just how much the dielectric of the insulation can change, and if that change is audible.  And is it a change for the better?

Exactly, this is apples and oranges--electrolytics use an oxide layer microns thick as a dielectric and involve very complex surface layer chemistry, it is no wonder that this can over time behave in a very complicated fashion--just getting an electrode of any type to behave in a stable fashion is not trivial. Now we are comparing this with polymers mm thick, it isn't reasonable to compare the two.
John

[denverdoc]

On another note off topic to denverdoc, I was wondering how you
implemented the recommended notch filter in your system. Were you able
to do this electronically or did you use the passive component approach.
Here is a link to an interesting study of the BG 75 performance characteristics. http://ldsg.snippets.org/ALSR/dbsindex.html
Scotty
.

Scotty,
Thanks for the link though I have visited there many times in hopes of better understanding msmt issues. Right now I am not using the big ribbons, but hope to do so in the next week after making outdoor msmts. I wanted to first familiarize myself with DEQX using less difficult drivers before tackling this monster.

I will simply let the DEQX eq out the cavity resonance as it will do so far more accurately and w/o phase issues than any anolog notch filter.
John

[-Richard-]

So...the more carefully we construct our "testing"
methods...as nicely described by denverdoc and ctviggen...
to eliminate the influence of ones self-interest...psychologically
speaking...in the outcome...what denverdoc accurately calls our
"expectation factor"...the more obvious it appears that we
would have to apply a rigorousness that would be counter-
intuitive to the sense of delight that fuels our involvement
in the first place...

In a very real sense it would seem safe to say that what
we have here is a love affair with technology...and to a
certain extent...technology for its own sake...

And why not?

Why shouldn’t we give ourselves permission to play with toys
that appear to give us so much satisfaction...and not only
toys...but wires...capacitors...and so on?

It conjures up in my mind garage robotics...

Several years from now we may be the very same people who
begin to put together robots from spare parts...from
catalogues...think of the chat rooms conversations built
around that involvement!...

denverdoc points out that there is strong similarities between
habitual cocaine use and the kind of activity we engage in with
our frequent search for audio nirvana...and I am not surprised...

I cannot help feeling that there is a sexual component at play
here as well...putting aside the idea that at the heart of all
addictions is a kind of masturbatory reflex at work...it is still
surprising how many times I read in audio threads that the
male partner of a couple must “sneak in” a component so
that the wife is unawares of his latest purchase...on a
metaphorical level this certainly seems like the acting out of
behavior that is illicite in nature...and that “covetousness”
must add to the fun of the whole “affair”...

On the scientific side of things I like Occam’s honesty...
”...While I still think I remember the difference between plausible, indicative,
compelling, and conclusive, I simply rationalize my poor scientific methodology
as lack of resources...”

But not a lack of humor and a good dose of self-knowledge thrown in as well...

Audio people are really a very interesting culture...I like being a part of it....

Silver or copper?

Warmest regards -Richard-

[AphileEarlyAdopter]

Exactly, this is apples and oranges--electrolytics use an oxide layer microns thick as a dielectric and involve very complex surface layer chemistry, it is no wonder that this can over time behave in a very complicated fashion--just getting an electrode of any type to behave in a stable fashion is not trivial. Now we are comparing this with polymers mm thick, it isn't reasonable to compare the two.
John

I have been in this hobby for 10 years and I did not yet believe that digital cables make a difference leave alone the burn-in. But I DID hear for sure the exaggerated bass and highs of the new digital cable, which also implies, that a digital cable can make a difference.
So it all depends, on how much experience, you have in 'listening' to various amps/speakers and other tweaks some of which may not have a scientific basis at all.
I would like to first get the theoretical possibility agreed upon. The 'audible' part is subjective, which I am not all interested in debating about.  I am only interested in theory. I will take care of the 'audibility' part with my own experiments.  There is a wealth of information now in how cables play a role while interfacing audio components. I have been reading all this for the last few years and only now I feel confident to even narrate my own experiences in a public forum.
I have no problems with audiophiles trying various tweaks (that certain things are overpriced or even have a price is a different issue). The experiments come first, the results later and the scientific explanation the last. The goal is to improve the sound of a system.

[denverdoc]

I have been in this hobby for 10 years and I did not yet believe that digital cables make a difference leave alone the burn-in. But I DID hear for sure the exaggerated bass and highs of the new digital cable, which also implies, that a digital cable can make a difference.
So it all depends, on how much experience, you have in 'listening' to various amps/speakers and other tweaks some of which may not have a scientific basis at all.
I would like to first get the theoretical possibility agreed upon. The 'a ...

I think we are in agreement that what you heard may have been real--what some of us debate is whether the cable actually changed or your ears acclimated to the sound. Using Occam's razor, it is much easier to believe the latter than turn physics upside down by postulating changes with no known physical basis, and instead consider the software between the ears which is terribly adept at habituation--as I said originally the brain is basically a differential amp at the core.

I, too, am heavily in favor of experimentation, but wonder how many guys out here have actually taken the time to accurately measure their speakers in nearfield and listening positions. Typical setup might have 20dB of ripple in it. These same people then  spend 100's or even thousands on cables that might contribute  0.1 of a dB difference at some frequencies, and shout about the vast improvement. To me it seems rather like losing the forest for the trees. They of course have the right to spend their money any way they see fit, but to extoll the rhapsodies of a particular item w/o bothering first to see whether they can reliably a/b it, seems to do us all a potential disservice. I know I am shouting into the wind of popular opinion on this one, but again invite anyone to try blind a/b testing--your convictions will likely lose a little of their certainty. As did the Audio magazine reviewers when for several months they tried to confirm their subjective impressions.
Cheers,
John

[Digi-G]

I have to admit - I was quite skeptical of electronics break-in.  At least that it was audible.  I always thought that it was bunk - Hey, look at me, I'm an audiophile and I hear EVERY little thing!  Until I got my Odyssey Stratos Extreme amplifier.  The break-in it went thru was NOT subtle.  Over just several days the amp would be boomy, then have no bass whatsoever, then get considerably louder/quieter.  Not subtle - definitely audible.   It was so extreme (no pun intended) that I called Klaus at Odyssey, concerned that the amp was defective - he assured me that was normal break-in behaviour.  I can't say I've experienced this with other electronics (like my receiver or dvd player).  My speakers did change, but it was more subtle and over a period of time.  Wires/interconnects breaking in?  C'mon...