AudioCircle
Other Stuff => Archived Circles => General Archive => Topic started by: sneezingdog on 1 Oct 2010, 12:18 am
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What is the scientific/engineering basis for the break-in/burn-in effects, esp for different components, like batteries, or cables or circuits or speakers? What's happening when beak-in occurs? :scratch:
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As far as speakers, it is likely primarily the physical effect of the cone's or dome's surround and the spyder softening and becoming more compliant.
As far as wires and capacitors, many audiophiles will parrot that the "dielectric has to form", but most have absolutely no actual idea of what that means or entails, scientifically speaking.
Steve
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This may just well prove to be an interesting conversation. (http://maanclan.com/images/smilies/popcorn.gif) Carry on men.....
Bob
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I think it just an environment break in. You buy something made in the south and ship it north it needs time to climatize or vise versa. Also individual devices shipped in from different countries that make up the bought piece might need to climatize to it's permanent environment. Break-in is all about the weather and its shows up in our hearing ability somehow.
Don't know its just another whacked out theory of mine.... :lol:
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Here's an interesting article from Danny Richie about how driver Ts parameters can change over time during break in:
http://www.gr-research.com/burnin.htm
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What is the scientific/engineering basis for the break-in/burn-in effects, esp for different components, like batteries, or cables or circuits or speakers? What's happening when beak-in occurs? :scratch:
The change is occurring at the molecular level as materials, magnetic fields, align tighter and more linear after being expose to electric current. :smoke:
example 1: Take a newly formed river. The water flow is widely dispersed taking various paths. However over time a river bed begins to form, where the water flow can concentrate with less resistance, thereby increasing the speed of the river.
example 2: Take a rack of billiard balls. When the balls are tightly racked, the transmission of energy from the break ball travels efficiently through the cluster of balls. Whereas loosely racked, break energy is dispersed and lost.
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Most of the "break in" is between your ears.
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This may just well prove to be an interesting conversation. (http://maanclan.com/images/smilies/popcorn.gif) Carry on men.....
Bob
Ha! Let's see, my guess is three major fights, two inferences of mental deficiencies, and one claim that your system (hearing) sucks right after a claim that that you'll say my system (hearing) sucks. It will take two and 1/2 pages for the facilitator to post a warning and four posts after that to lock the thread.
Wadda ya think? :lol:
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Your hearing sucks.
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Your hearing sucks.
I'll meet you after school in the parking lot.
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I find it interesting that audio reviewers find that virtually every link in the audio chain improves after break in. Thermodynamics teaches that entropy increases. My experience with musical instruments and photo gear confirms this law. My observations with fine pianos, saxophones and guitars tells me that they are at their best when new or newly setup. Same with Hasselblad, Leica and Zeiss--best when new. I believe that what does change is the listener's perception as the senses and brain adjust and adapt to changes. Think of new glasses that are uncomfortable and distort vision at first. After a couple days the pressure points and distortion fade away. Did the frame and lenses "break in"? Does the picture on your HDTV improve after the capacitors "form"? I don't remember reading any audio review where the reviewer reported that the subject of review was great at first, but seemed to "wear out over time" as thermodynamics predicts it will. Odd.
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It's really easy.
Get two of whatever you'd like to hear. Run one for about 500 hours and leave one in the box.
After 500 hours do an A/B and I think you'll hear the difference pretty easily.
Some components change more over shorter periods of time, but they do change. I always wondered if it was "getting used to it" instead of the sound changing, but I've done this a few times with different components and it's always the same thing.
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Ha! Let's see, my guess is three major fights, two inferences of mental deficiencies, and one claim that your system (hearing) sucks right after a claim that that you'll say my system (hearing) sucks. It will take two and 1/2 pages for the facilitator to post a warning and four posts after that to lock the thread.
Wadda ya think? :lol:
Agreed, but things seem to be moving along fairly peaceful so far.
Maybe there's hope for us yet? :lol:
Bob
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When I buy a pair of jeans, those jeans are certainly in the best condition they will ever be at the time of purchase. As I wear the jeans, the jeans start to deteriorate little by little, but they actually become more comfortable. The degradation allows them better to conform to my shape, and make allowances for the irregularities of my body.
I think it works this way with audio components. The more time they spend in close proximity to my ass, the better they sound.
Chad
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What is the scientific/engineering basis for the break-in/burn-in effects, esp for different components, like batteries, or cables or circuits or speakers? What's happening when beak-in occurs? :scratch:
There is no proven basis for many "break-in" claims.
Mechanical items do break-in. This is well-accepted. So, speakers may well be subject to break in. I've seen measurements of drives during break-in and the T/S parameters can change.
Things like a turntable, CD or DVD transport, and RtR tape deck probably show some break-in effects. Whether it's audible or not is debatable. Still, if someone said their turntable smoothed out after 100 hours I'd give them the benefit of the doubt. There's a basis in fact.
Some electronic components like capacitors need to "form" the first time they're used (and after long periods of disuse). That's not really break-in, and it doesn't take very long.
Other than that, there isn't any real evidence for "break-in" of electronic components. There are a lot of people who try to explain it one way or another, but there isn't a factual basis to any of it, and they can never show measurements that illustrate their claims. They can't even show that they can actually hear a difference when subjected to a controlled test.
So, things like wire "break-in" are faith-based, like a number of other things about high-end audio.
It's up to you whether you choose to believe in it or not.
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The change is occurring at the molecular level as materials, magnetic fields, align tighter and more linear after being expose to electric current. :smoke:
Can you show some proof for this idea?
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I think it works this way with audio components. The more time they spend in close proximity to my ass, the better they sound.
But this is a mechanical effect. A wire conducting an electrical current is not mechanical, and thus can't be compared to a pair of jeans getting worn.
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Does it really matter? With scientific proof in one hand, would you suddenly start hearing break in? You naysayers are such a hoot! If there were no scientific evidence to support where babies came from, you’d try to convince everyone sex has nothing to do with it! :lol:
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sneezingdog - Why did you have to start this thread ! :evil: :duh:
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sneezingdog - Why did you have to start this thread ! :evil: :duh:
Yeah...I suppose my question was a bit naive. I haven't had a good music system for years and years. I'm putting one together now and have been reading various forums, reviews, etc. Lots of talk about break-in/burn-in even for things like cables. Many, many people report hearing it, sometimes in stages over hundreds of hours of use; too many to write it all off to imagination. So just wondering what the underlying science/engeneering was. I'm getting the impression that there probably is some basis in fact (speakers seem like a good example) and that it shouldn't take hundreds of hours to occur. I was thinking of just letting my system play while I am out during the day (as others seem to do), but don't want to tourture the dogs either. They are border collies and already a bit on edge.
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Of course the music sounds better after a few plays--your new equipment just needed some time to learn the tunes! :)
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Most of the "break in" is between your ears.
I'm sure this is the case. Same for "warming up" solid state gear. It's not the gear that changes over half an hour, but our hearing and perception.
--Ethan
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"Other than that, there isn't any real evidence for "break-in" of electronic components. There are a lot of people who try to explain it one way or another, but there isn't a factual basis to any of it, and they can never show measurements that illustrate their claims"
I don't know why, but this brings to mind the tens of thousands of reports of people seeing UFOs - yet to date there's not one shred of scientific evidence to support their existence. Does that mean what they saw was only in their minds?
If you can clearly hear improvements as a component breaks in, or you really did see a UFO, does the lack of scientific validation negate your experience?
Terrible analology but this seems like a pretty freeform thread, so there it is.
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When I buy a pair of jeans, those jeans are certainly in the best condition they will ever be at the time of purchase. As I wear the jeans, the jeans start to deteriorate little by little, but they actually become more comfortable. The degradation allows them better to conform to my shape, and make allowances for the irregularities of my body.
I think it works this way with audio components. The more time they spend in close proximity to my ass, the better they sound.
Chad
This may be the funniest post I have ever read on this site :lol:
Thank You.
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there isn't any real evidence for "break-in" of electronic components
If there is no measurable evidence, there sure is a lot of empirical evidence, that is, not by prior knowledge, but by experience. There is so much experiential evidence cited by so many, you may just have to acquiese ever so slightly on that basis alone.
Just found this in my Richard Gray user's manual. "...it can take up to 24 hours or more for the devices' full effects to be realized, not unlike breaking in any new component. Why should this be so? RGPC Parallel Power devices actually enable your components' power supply capacitors to charge and discharge more quickly and completely, and it takes a bit of time for this 'capacitor retraining' process to be completed" (RGPC, 2007, p.6).
Richard Gray Power Company (2007). Product Manual.
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Ethan, you know very well, or you should,that a transistor based power amp will show a higher THD figure until the output devices reach their thermal equilibrium which is usually well above ambient room temperature. Tubes,being THERMIONIC devices also have a warm up period.
Scotty
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It's really easy.
Get two of whatever you'd like to hear. Run one for about 500 hours and leave one in the box.
After 500 hours do an A/B and I think you'll hear the difference pretty easily.
Some components change more over shorter periods of time, but they do change. I always wondered if it was "getting used to it" instead of the sound changing, but I've done this a few times with different components and it's always the same thing.
Tonepub nailed it on the head ... try it and find out for yourself if you don't believe or can't or don't want to hear the difference that break-in has on sound produced by audio equipment ...
For me - the easiest has been the headphones - as they are so easy to swap - it only takes a few seconds - I have done my share of A/Bing the phones - I did that with two sets of AKG701headphones ...
Yes it is also true that break-in also happens in your head - if one has decided that break-in has no affect on sound then for that person it doesn't - who is to convince - besides it is a hobby ... a form of entertainment ...
Cheers
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I think it works this way with audio components. The more time they spend in close proximity to my ass, the better they sound.
Chad
Sometimes I enjoy sitting on my sub.
I strongly believe in break in for speakers. Fs has dropped by 5Hz after a period of 1 year.
Recently I purchased a pair of Nike shoes. While wearing them for the first time, I tried breaking them in by doing a 3 mile run. After the run, I had blisters on my feet. One week later, they healed and I thought maybe the shoes had broken in fully, but it was just my body bracing itself for more blisters, and had sped up growth of thicker skin to protect itself from abrasions.
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With my engineering background in mechanical and electrical, I can say that every material, every alloy assembled by man, nature immediately starts to dis-assemble. Look at all the products you have, even your home, car, the stereo and even our bodies, they all begin the deterioration process. Many sub-atomic bonds between atoms or molecules are in an unhappy relationship.
If we accept this statement, then clearly components within a preamp or power amp are also in the deteriorating process (tho it may be slow). The question that I have to ask, how does material breaking down know how to sound "good"? In otherwords, just because something is "breaking in" doesn't mean it should sound better, maybe it sounds even worse. But the break-in believers always claim that it sounds better. How do the atoms and molecules know that if they "break-in" a certain way, the human's ears will perceive that as pleasant?
I do agree that speaker surrounds and mechanical things may loosen up over time, but then did they loosen up too much and now the (example) speaker surround does a worse job controlling the driver's movement?
Wayner 8)
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How do the atoms and molecules know that if they "break-in" a certain way, the human's ears will perceive that as pleasant?
That is an excellent question and point.
Steve
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...Look at all the products you have, even your home, car, the stereo and even our bodies, they all begin the deterioration process...
If we accept this statement, then clearly components within a preamp or power amp are also in the deteriorating process (tho it may be slow). The question that I have to ask, how does material breaking down know how to sound "good"? In otherwords, just because something is "breaking in" doesn't mean it should sound better, maybe it sounds even worse. But the break-in believers always claim that it sounds better. How do the atoms and molecules know that if they "break-in" a certain way, the human's ears will perceive that as pleasant?
The sounding better or not part is surely the human contribution to the phenomena. If everyone reporting a change in sound after use (deterioration) happens to agree that what they are hearing is better (they just like it more), well that's just accidental, but interesting for that fact alone.
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Wayner said,
I do agree that speaker surrounds and mechanical things may loosen up over time, but then did they loosen up too much and now the (example) speaker surround does a worse job controlling the driver's movement?
No,not if the engineer accounted for this in his original design. What has not been done is a measurement of a drivers THD and IM in an unbroken in condition and then a second measurement after 500 hours of heavy use. I have heard the break in phenomena with drivers and in this case there should be something to measure. How do the atoms and molecules know that if they "break-in" a certain way, the human's ears will perceive that as pleasant?
Good point they don't. I have no explanation for why running an electrical signal through a conductor or a complete electronic device changes its sound for the better but to me it does. In the case of wires, RCA plugs and jacks however, a designs characteristic sound doesn't seem to change in a gross fashion even after break in. If I don't like it when I first hear it I usually don't like it after extended use.I wish I could tell by looking which design was going to sound poor in comparison to another but I can't. In many cases involving cables there are no images of the cables geometry,strand count or LCR measurements. That leaves listening to them to sort them out. If some people can't hear any repeatable differences between things that's okay.
I can and I act on the empirically obtained evidence accordingly.
Scotty
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Just for the hell of it, I will be the D's Advocate since it's Friday afternoon and I am counting down to "Miller" time.
The energy from the power supply (AC/DC) is organizing the molecules and creating a temporary reduction of entropy. Thus the sea of (delocalized) electrons in the Cu/Ag/Pd/Au/Ni/Pt wires are more aligned and conducive to cleaner signal transfer.
How's that?
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With my engineering background in mechanical and electrical, I can say that every material, every alloy assembled by man, nature immediately starts to dis-assemble. Look at all the products you have, even your home, car, the stereo and even our bodies, they all begin the deterioration process. Many sub-atomic bonds between atoms or molecules are in an unhappy relationship.
If we accept this statement, then clearly components within a preamp or power amp are also in the deteriorating process (tho it may be slow). The question that I have to ask, how does material breaking down know how to sound "good"? In otherwords, just because something is "breaking in" doesn't mean it should sound better, maybe it sounds even worse. But the break-in believers always claim that it sounds better. How do the atoms and molecules know that if they "break-in" a certain way, the human's ears will perceive that as pleasant?
I do agree that speaker surrounds and mechanical things may loosen up over time, but then did they loosen up too much and now the (example) speaker surround does a worse job controlling the driver's movement?
Wayner 8)
I don't know that break-in believers always believe the component sounds better. There are just as many comments made about components that sound great at first but after a time not so much. The positive comments are just more enthusiastic and more likely to be shared. I'm unsure about break-in myself but I do believe the human 'delusion' element is overstated when it comes to long-term listening. My ears are sensitive and there are just some sound qualities to which I cannot acclimate no matter how much I try -and I've tried. Especially once I became aware of how good audio reproduction could be. I mean sure I could go over to a friend's house and watch a movie with the sound coming from the TV speakers and become engrossed, pulled in and have me heart move with the dialogue and music cues and forget about the sound quality - but that doesn't mean my separates don't sound better.
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Scotty,
The good folks at Acoustic Research (inventors of the acoustic suspension) and their wonderful AR-3a had no idea that 30 years later, their woofer surrounds would crumble to dust. I'm not sayin' that engineers don't try to plan for "things loosening up" (as opposed to the break-in theory) and most is just hopefully good guess-timating. Does the identical speaker playing in Toronto sound or have the same measurements as one that plays in Denver or Phoenix?
Wayner 8)
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Again, it isn't a matter of knowing why a phenomenon occurs--knowledge is also gained through experience, and this is what many of you "show me the facts" folks don't have--you lack experience. For eons, people experienced the Aurora Borealis. They had absolutely no way of explaining it, no knowledge whatsover of the ionosphere, but they did, and do, experience it. We still don't know everything about tornadoes, but they sure do happen. So, if you lack experience in equipment burn in, perhaps you should get some. Until you get some real-world experience, go back to those who tell you what to believe. If those who have told you what to believe have some scientific proof that equipment cannot possibly break in, then you would have cited those articles, but you cannot, can you? You cannot, because even those who require science have no basis by which to make their claims. On the other hand, I have personally experienced and attest to my new or modified equipment having sounded better over time. I cannot explain this, but there it is.
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If there is no measurable evidence, there sure is a lot of empirical evidence, that is, not by prior knowledge, but by experience. There is so much experiential evidence cited by so many, you may just have to acquiese ever so slightly on that basis alone.
Prove you can hear it.
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Yes it is also true that break-in also happens in your head - if one has decided that break-in has no affect on sound then for that person it doesn't - who is to convince - besides it is a hobby ... a form of entertainment ...
Yes, that's exactly it.
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woodsyi,I like it,but why is there no immediate return to the unorganized ground state when the electron flow is halted.
An answer to one question always seems to raise another question.
Scotty
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Yes, that's exactly it.
The it's in your head argument is pretty tough to swallow. That's a very slippery slope, and ultimately leads you can't trust anything you hear or you believe that certain people are more qualified than you to know what you should hear. I find skeptics tend to lean towards the latter.
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Prove you can hear it.
Turkey, I have my own proof--I have experienced it. Get your own.
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With my engineering background in mechanical and electrical, I can say that every material, every alloy assembled by man, nature immediately starts to dis-assemble.
Even a diamond? Those covalent bonds are mighty strong.
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So, if you lack experience in equipment burn in, perhaps you should get some. Until you get some real-world experience, go back to those who tell you what to believe.
I suppose the proper response would be, "Don't try to teach your Grandma how to suck eggs."
If those who have told you what to believe have some scientific proof that equipment cannot possibly break in, then you would have cited those articles, but you cannot, can you? You cannot, because even those who require science have no basis by which to make their claims.
You have it backwards. You are the one making the extraordinary claim, so the burden of proof lies with you.
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We are not discussing the Aurora Borealis here. That was a visual happening that early man could not understand until it was scientifically explained, and the explanation stood the test of time and critics.
The thread speaks of Scientific Basis of Break In and so far, there are none. Many opinions, but that is about it. Several times in my life, I have held to some very strong beliefs, that later were proven wrong. Other elements that were not even considered came into play that changed the playing field (and my opinion). The lesson learned is that what you think is the absolute truth is actually a break down of the minds willingness to accept a theory based on a couple of apparent details, details that actually are quiet deceiving to the true nature of what is actually happening.
Wayner
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Wayner,I suspect that in many cases they do have the same measurements. The unit to unit variation in many drivers now in production is much lower than it was 20 years ago. Robotic assembly and superior control of raw material quality has contributed to this. Many drivers have production tolerances that are so tight that they no longer have to be pair matched before using them in loudspeakers.This is especially helpful
when replacing the occasional blown driver.
Scotty
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Scotty,
I agree that they may leave the factory that way, but humidity, elevation, temperature and a whole bunch of other things will make each speaker sound a tiny bit different. That is where I was going.
Wayner
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Turkey, I have my own proof--I have experienced it. Get your own.
That's not proof, anymore than you seeing a flying saucer is proof that _they_ exist.
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You have it backwards. You are the one making the extraordinary claim, so the burden of proof lies with you.
I am not making an extraordinary claim. I have experienced a sound improvement over time with my new equipment, that is all, that is it, pure and simple. You have not, so you insist that I have not. You just don't get it, and you never will, until you have experience.
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Jimi Hendrix was "experienced" and now he's dead.
Wayner :lol:
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This should be good. :lol:
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The it's in your head argument is pretty tough to swallow. That's a very slippery slope, and ultimately leads you can't trust anything you hear or you believe that certain people are more qualified than you to know what you should hear. I find skeptics tend to lean towards the latter.
I don't trust my hearing when it comes to things like this. I know I can be fooled or mistaken. I require more proof than that - like the results of controlled tests.
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Jimi Hendrix was "experienced" and now he's dead.
Wayner :lol:
So do you get an Audio Mystic to hold a seance and contact Jimi from beyond the grave? Or will a regular Mystic work just as well?
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I wonder if they will even sound different. I would want to verify a measurement difference due to relative humidity and barometric pressure first. I would leave the ambient temperature out of the test as most people prefer to listen at room temperature.
Scotty
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So do you get an Audio Mystic to hold a seance and contact Jimi from beyond the grave? Or will a regular Mystic work just as well?
:lol: I just play his records!
Wayner
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I don't trust my hearing when it comes to things like this. I know I can be fooled or mistaken. I require more proof than that - like the results of controlled tests.
Controlled tests would be great. I certainly wish more time was spent coordinating some instead of wasting bandwidth.
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I don't trust my hearing when it comes to things like this.
Same here. That's why I purchase equipment that does not require break in.
Jimi Hendrix was "experienced" and now he's dead.
RIP Jimi !! What a well endowed man! :lol: :green:
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Turkey, under what conditions do you use what you hear as a basis for making a buying decision?
When do you trust what you hear to be real and not an illusion? Does it always take external corroboration from tests and measurements to support any conclusion you may reach?
Scotty
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Controlled tests would be great. I certainly wish more time was spent coordinating some instead of wasting bandwidth.
I'm not really motivated to do them in this case. I haven't heard the differences that people are claiming for break-in of things like wire.
I've done tests in the past, and found one Audiophile Myth after another to be busted.
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It's like buying wine. To me there are only 2 kinds of wine, the ones I like and the ones I dislike.
When it comes to stereos, I think they sound different every day. It's me or the atmospheric conditions or some other cause. Also, my own "audio memory" just isn't good enough to say the system sounded better 10 minutes ago. I think music sounds different with the eyes open or closed.
Wayner :D
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Turkey, under what conditions do you use what you hear as a basis for making a buying decision?
When buying CDs, or perhaps speakers.
When do you trust what you hear to be real and not an illusion? Does it always take external corroboration from tests and measurements to support any conclusion you may reach?
When it comes to "do I hear a difference or don't I hear a difference," I now always require corroboration. I've been fooled in the past, so I've raised the bar.
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turkey,you might be interested in doing a simple experiment. Build two sets of ICs. The first set should be constructed out of 26ga. single strand magnet wire. You might loosely twist them together to make handling them easier. The second set should be constructed 12ga or 14ga wire with a strand count of 128 or 256. These should also be a twisted pair geometry about 1 twist per 2 inches. The hope is that you might be able to consistently hear a difference between to the two widely different construction geometries and the different LCR measurements between the two cables. If you can hear the difference between the two cables,then you should build a second set of cables,the magnet wire set would be easiest and compare the sound the two cables. Hopefully you might hear a difference between the first set which has been use for a couple of weeks and the set you just made.
You could report back on the results of your experiments.
Scotty
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Wayner,I agree that it is easier to focus on the music with your eyes closed. Our dominant sense is sight and it is all to easy to be distracted by what we see to the exclusion of what we should hear.
When I sold stereo gear back in the 70's I would always try to get the the prospective client to close their eyes while listening to the music on the systems. When they would do this it was easier for them to focus on how the system sounded. Hopefully they liked sound of what their budget would allow them to buy. The nice thing was that when the stereo system was delivered to their home it always sounded much better than it did in the store.
Scotty
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turkey,you might be interested in doing a simple experiment. Build two sets of ICs. The first set should be constructed out of 26ga. single strand magnet wire. You might loosely twist them together to make handling them easier. The second set should be constructed 12ga or 14ga wire with a strand count of 128 or 256. These should also be a twisted pair geometry about 1 twist per 2 inches. The hope is that you might be able to consistently hear a difference between to the two widely different construction geometries and the different LCR measurements between the two cables. If you can hear the difference between the two cables,then you should build a second set of cables,the magnet wire set would be easiest and compare the sound the two cables. Hopefully you might hear a difference between the first set which has been use for a couple of weeks and the set you just made.
You could report back on the results of your experiments.
Why twisted pair? It's an unbalanced connection.
I've done tests of wire a couple of times now. Once about 30 year ago, and once about 8 years ago. We did no better than random chance at picking out which wire was which.
I'll buy 2 patch cords at Radio Shack and use one and not the other. Then I'll have my wife plug in one of the sets without my knowing which and I'll see if I hear any difference. I'll repeat it a few times and see what happens.
You say I should let one pair "break-in" for 2 weeks?
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I would like to "front load" the experiment with the two very different cable geometries and construction types to maximize the chances of your hearing a difference. In the case to the two different cable geometries there is at least a measurable difference in LCR parameters and their real world performance with electrical signals to base the possibility of your hearing a difference on. In the second case of cable break in this is a phenomena which to my knowledge isn't currently measurable. The first test with two very different cables would serve to establish a threshold of detection hearing wise. If you can't detect the difference between the two cables with very different geometries then it is unlikely you will hear any difference between two identical cables regardless of their break in condition.
Scotty
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I would like to "front load" the experiment with the two very different cable geometries and construction types to maximize the chances of your hearing a difference. In the case to the two different cable geometries there is at least a measurable difference in LCR parameters and their real world performance with electrical signals to base the possibility of your hearing a difference on. In the second case of cable break in this is a phenomena which to my knowledge isn't currently measurable. The first test with two very different cables would serve to establish a threshold of detection hearing wise. If you can't detect the difference between the two cables with very different geometries then it is unlikely you will hear any difference between two identical cables regardless of their break in condition.
Scotty
I'm not really that interested in comparing wires. It's boring.
It is, of course, possible to create wire that sounds different by being abnormal in L, R, or C. I don't think that is in dispute. I don't know whether the two wires you propose differ in these areas enough to be audibly different or not. I don't really care, to tell you the truth.
I stick with coax of reasonably low capacitance. I have heard what OmegaMikro unshielded wire does to a system and I don't care to inject large amounts of garbage into mine.
I'm willing to test break-in, but that's as far as I go. I consider the wire issue to be resolved, and I don't need to establish my hearing acuity. I've done enough tests with other people to show that I'm normal in that respect.
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Bluejeans cable, 12pf per foot. Awesome coax!
Wayner
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The reason I chose those two cable geometries is that they are in common usage in the audiophile community and people within that population would agree that they sound different from one another. What defines an abnormal geometry when it comes to audio ICs is something I can't answer. The pundits say that DC to light bandwidth is not necessary in a cable carrying audio band signals. I think the two examples I gave would fall into the realm of adequate for audio signal transmission. I would think the chance to learn something new about yourself and your system would be compelling enough to get you try the experiment.
The construction phase of the cables would take longer than the listening test session. You stick the cables in and you hear a difference or you don't. The differences between the two should easily be gross enough in nature that no SBT or DBT testing is necessary.
If you are not interested in the cable geometry experiment that's cool,frankly I suspect that if you do the break in test with couple a Shack patch cords you may not hear any difference. You may have a chance if you system resolution has improved compared to what it was 8 years ago. If it is about the same then you are effectively doing the same experiment over and expecting a different outcome and you know what
Einstein said about that kind of behavior.
Scotty
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When it comes to stereos, I think they sound different every day
Wayner, a truly great system always sounds good. With a mediocre system, you may have to talk yourself into it from day to day. Have a nice day.
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I'll buy 2 patch cords at Radio Shack and use one and not the other. Then I'll have my wife plug in one of the sets without my knowing which and I'll see if I hear any difference. I'll repeat it a few times and see what happens.
Well, when you compare crap to crap, what else would you expect?
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I don't trust my hearing when it comes to things like this. I know I can be fooled or mistaken. I require more proof than that - like the results of controlled tests.
controlled tests like this no doubt
http://www.youtube.com/watch?v=fn7-JZq0Yxs
go past the crap at the beginning and move up around 20secs or so....
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Well, when you compare crap to crap, what else would you expect
Good point, face. A few posters here who come from a certain owner's circle feel that the point of this hobby is to spend as little as possible and then to sneer at those who would rather make an investment in truly high-end gear. They never get beyond a certain level of crappy mid-fi and cannot understand that others hear music differently from each item they place in the chain, including cables. When someone can finally achieve a truly high resolution system, then magic begins to occur that cannot be heard with mid-fi components, and especially with lo-fi junk such as Shack patch cords and speaker wire from Anti-Cable, Blue Jean and even recommended from Home Depot of all places!
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Good point, face. A few posters here who come from a certain owner's circle feel that the point of this hobby is to spend as little as possible and then to sneer at those who would rather make an investment in truly high-end gear.
It's called reverse snobbery.
When someone can finally achieve a truly high resolution system, then magic begins to occur that cannot be heard with mid-fi components, and especially with lo-fi junk such as Shack patch cords and speaker wire from Anti-Cable, Blue Jean and even recommended from Home Depot of all places!
IMO, BJC's Canare 4S11 is a great cable, as long as long as you avoid BJC's crappy connectors. As for the other cables mentioned, they're great if you like colored sound or if you don't mind buying new cable every few years due to oxidation. :wink:
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It's called reverse snobbery
Yes, thankyou. It's comes from being told the "establishment" can be beaten by finding cheaper alternatives to everything, so the cheaper the price, the "better" the product, the more glorious the triumph. Sorry if I criticized a BJC in your system--I have not heard them, just had to counter Wayner, who enjoys search and destroy missions on certain topics such as these.
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Very well said Mr. KURO!
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I have not heard them, just had to counter Wayner, who enjoys search and destroy missions on certain topics such as these.
With 9 posts on this forum how would you know this? Just curious.
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Some people lurk for years before posting.
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With 9 posts on this forum how would you know this? Just curious.
If post count has a direct correlation with audio knowledge, we're in trouble. :D
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That would make me one of the smartest folks around here. :o
Although, I do think one should temper their comments until they've earned the right to poke at respected members like Wayner.
just sayin'
Bob
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Stay on topic please.
This thread is getting personal and unfortunately isn't offering any particularly novel insights.
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If post count has a direct correlation with audio knowledge, we're in trouble. :D
Are you kidding?
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This is kind of a touchy subject but I'll put in my two cents.
Many of the things that we build can be charted on a bell curve (an inverted "U").
As it breaks in it begins the upwards slope until it's at the top of it's performance capability and it should remain up there for quite some time.
Eventually things wear and degrade and it's all downhill from there.
Take an engine, for instance. As it breaks in horsepower rises and oil consumption lessens; as it wears, you have more blow-by, gasses are going past worn valves, parts get worn past tolerance and eventually it needs a rebuild.
I think that everyone here will agree that you can certainly hear the changes in speakers, headphones, tubes and cartridges as they break in and reach their optimum state.
On your own system it's only when things are really going downhill fast that you can detect when it's replacement time as the process is a gradual one. You get used to the degredation in the sound quality because it's occuring so slowly.
Seemingly everything that we make changes over time and most things seem to improve when they're used on a regular basis - up to a point.
If the performance (lifespan, if you will) of a speaker, tube, capacitor, etc. resemble a bell curve, it seems reasonable that most other things in your audio system would follow suit.
No scientific data but perhaps an EE could chime in as to whether or not my reasoning is correct?
I just remembered something; somewhere in this thread there was mention of solid state and warm up. I'm paraphrasing here but in the VTL Book, David Manley stated not to bother doing any critical listening until roughly 30 minutes had gone by.
The tubes take only 10 minute to reach proper temperature but it was the wiring and everything else that would take another 20 minutes.
It's the strangest thing - when maybe 25, 30 minutes go by my systems just do a really abrupt snap into focus. One second it's this sounds okay and then it's wow, this sounds great!
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I just remembered something; somewhere in this thread there was mention of solid state and warm up. I'm paraphrasing here but in the VTL Book, David Manley stated not to bother doing any critical listening until roughly 30 minutes had gone by.
The tubes take only 10 minute to reach proper temperature but it was the wiring and everything else that would take another 20 minutes.
It's the strangest thing - when maybe 25, 30 minutes go by my systems just do a really abrupt snap into focus.
Nice points Steve. To expand further, warm up involves changes in capacitor and stray capacitance values (both tube and SS components), transformer winding capacitance/inductive reactance/leakage reactance changes (in tube equipment), and even resistor values, although normally minimal changes depending upon material used. Carbon is the most unstable resistance material that I know of in resistors.
Bipolar transistors change characteristics in dramatic fashion VS temperature changes and easily result in thermal runaway unless precautions are observed; but even then characteristics, resulting in different distortion products etc, can occur during warmup.
Test equipment almost always requires a period of warmup time to stablize, before measurments are taken.
Cheers.
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Ha! Let's see, my guess is three major fights, two inferences of mental deficiencies, and one claim that your system (hearing) sucks right after a claim that that you'll say my system (hearing) sucks. It will take two and 1/2 pages for the facilitator to post a warning and four posts after that to lock the thread.
Wadda ya think? :lol:
Stay on topic please.
This thread is getting personal and unfortunately isn't offering any particularly novel insights.
Darn! I was a page and a half off. Took him till page four for the warning. I was pretty close with the insults and fights tho.
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Ethan, you know very well, or you should,that a transistor based power amp will show a higher THD figure until the output devices reach their thermal equilibrium which is usually well above ambient room temperature.
But what is the actual amount of change? From 0.002 percent distortion to 0.001 percent? That's a good example of something that is measurable but not audibly important.
Tubes,being THERMIONIC devices also have a warm up period.
Sure, and tube amps (with their output transformers) tend to have higher distortion too. That's why I was specific and said solid state.
This thread is yet another example of people missing that their own hearing is not totally reliable. Someone earlier in this thread said a good system always sounds good. That is simply not true. A good system can sound not so good when you're tired, or hungry, or in a bad mood. Mood is probably the biggest factor. But even when in a good mood our hearing is highly variable. I honestly don't understand why this is so hard for some people to accept. It's not a flaw to hear things differently over time! It's simply how our hearing works. It's also the most logical explanation for why we perceive "break-in" or "warm-up" for a solid state device, or wires etc, when measurements show no change or very little change.
--Ethan
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This thread is yet another example of people missing that their own hearing is not totally reliable. Someone earlier in this thread said a good system always sounds good. That is simply not true. A good system can sound not so good when you're tired, or hungry, or in a bad mood. Mood is probably the biggest factor. But even when in a good mood our hearing is highly variable. I honestly don't understand why this is so hard for some people to accept. It's not a flaw to hear things differently over time! It's simply how our hearing works. It's also the most logical explanation for why we perceive "break-in" or "warm-up" for a solid state device, or wires etc, when measurements show no change or very little change.
--Ethan
Thank You! I thought I was the only one that thought this...guess we're the minority here. :dunno:
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Your mood has a tremendous impact in how you think something sounds.
Sometimes you listen to an album or CD and can't wait for it to be over (too shrill, too muddy, hate the mix, hate the songs, whatever) and then you go back to it later on and you wonder why you shelved it for a couple of months.
It's been three decades but I'm still not willing to return to Side 2 of Live Peace In Toronto, though.
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Hi,
I am sure moods make some difference but does not explain what actually happens to a component during warm up. Since not much university scientific information has been presented, I thought I would expand on such for better understanding of heat related/warm-up concerns. Also check RCA Radiotron Designers Handbook, written by 26 engineers.
An audio component is actually quite dynamic during warm up, as we shall see. For ease in understanding, I am simplifying the discussion and not covering every issue. I am starting with parts, then negative feedback and comparing it to no feedback (open loop), as these have a major bearing on the discussion involved.
I think most understand that gainstage and passive parts conditions vary with temperature change, especially using bi-polar transistors, electrolytic capacitors, even transformers etc.
For example, under the most basic conditions, with no protection at all, bi-polar transistors are extremely heat sensitive and the hotter they become, the more collector current flows. "Thermal run-away" is the condition. This means that if enough power is available, "run-away" bi-polars will actually burn up (not including emitter followers). Of course such unstable conditions cannot be allowed to exist in any design but protection must be implemented. This information gives one at least an idea of what one has to deal with warm up issues with SS designs using bi-polar transistors. The problems are certainly no superficial. Tubes also require time to heat with the elements expanding and characteristics changing as well as passive parts changing characteristics.
Attempts to correct open loop variations (no feedback), such as harmonic distortion, frequency response, phase integrity etc, by applying some musical feedback voltage to correct the variations can help in certain respects, but also presents its own problems concerning warm up.
First, linear global feedback does not change the internal dynamics of a component per se. In theory it only samples the output of a signal, inverts it (180 degrees out of phase with the input signal), and feeds the inverted sample into the input, thus attempting to correct problems inherent in the open loop design. Global negative feedback can vary from little to very large amounts.
Linear global negative feedback reduces the higher gain portions of the audio band with respect to the lower gain portions of the audio band. Thus the bandwidth for a given -db is increased over the open loop design (no feedback applied). Imagine viewing a saucer bowl upside down on a table, viewing from the side. Now lower the top of the bowl (negative feedback applied). The bowl will appear flatter over a greater area, flatter frequency response over a greater range. Negative feedback "creates" a wider/higher frequency response as well as influencing other variables. (I hope the example helps one to understand.)
The actual effect of negative global feedback signal changes from cold to warm up conditions. Depending upon the open loop gain, bandwidth, phase response etc of the amplifier (which changes as it warms up) normal mid-band negative feedback (180 degrees out of phase with the input) actually becomes positive feedback at some high and low frequencies. Let's stick to the higher frequency example for ease.
Luckily protection measures are implimented to prevent oscillation from strong positive feedback at very high frequencies. However, just above mid-band frequency, "A" the negative feedback signal becomes only 170 degrees out of phase with the input signal, a little higher frequency "B" 120 degrees, at higher frequency "C" zero degrees out of phase and into positive feedback territory (although not oscillation).
As the "warm-up" temperature rises, points "A", "B", and "C" shift/change (Using single points simplifies the explanation, but the phase shifts occur over many octaves in the audio frequency range.), with many variables changing as a result. So feedback is not just "static" by any stretch of the imagination. Neither are active and passive parts.
If steps are taken to limit each individual stage's warm up shifts/changes, such as using local current feedback, then gain is reduced which means more stages, more parts, and "more power supply", which are not sonically perfect by any stretch of the imagination. With more stages, more problems such as higher order harmonics, phase shift problems, feedback from stage to stage through the power supply, etc results. (And remember, linear negative feedback reduces all harmonics by the same proportion, not selectively. And the higher the harmonic, the greater the weight it has with relation to the second harmonic.).
If steps are presented to increase gain but limit DC changes, such as
bypassing cathode/emitter/source resistors with electrolytic capacitors (or even other parts), then we have added more DA and DF capacitor problems or other part problems which themselves are, or can be temperature sensitive problems. (Almost forgot, DA and DF problems include the huge power supply electrolytic capacitors as well as film capacitors, although to a lesser degree.)
So warm-up not only changes individual active and passive part characteristics, but varies the relationship between feedback, especially global feedback, and the variables in the open loop portion of the design itself.
As mentioned earlier, another problem that some may be encountering is system masking of inner detail, distortion, and spacial Qs. In such a case, musical changes may not be noticable with temperature rise but then the system is not resolving all the musical information either.
As one can appreciate, an in depth engineering analysis reveals that what is actually occurring as a component heats is quite complex involving many parameters, and secondly, a component is a vibrant, dynamic device, not "static" in any sense.
Cheers.
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Marketing Basis of Break In....
Customer: Hey, this doesn't sound better in fact I can't hear any difference.
Manufacturer: You need to give it more time to Break In...you'll be "amazed" at how the soundstage will suddenly blossom after 4000 hours!!!
:icon_lol: :icon_lol: :icon_lol:
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Ethan, you are just throwing numbers around with the change in distortion vs.the operating temperature of a SS amp, by the way the figures you cited represent a 100% change from .002 to .001. .
Lets suppose the SS amp starts at 0.1% THD and falls to 0.05% I would willing to bet this would be audible.
Plus in addition to this simplistic view of distortion the amplifiers IM distortion behavior when it is below its normal operating temperature has not been considered, nor has its behavior with regards to transient signals been examined. SS amplifiers are frequently not entirely stable before reaching their normal operating temperature. The amplifier might be ringing when reproducing transient music signals which would fail to be revealed if amp is only tested with a simple 1kHz sinewave. All of these factors must be considered when discussing SS amplifier performance cold vs warm. Of course the fact that all amplifiers are not identical designs must also be considered which pretty much rules out the applicability of any blanket statement about the cold vs normal operating temp. sound of SS amps.
Scotty
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Lets suppose the SS amp starts at 0.1% THD and falls to 0.05% I would willing to bet this would be audible.
I'll take that bet.
Steve
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Ethan, you are just throwing numbers around with the change in distortion vs.the operating temperature of a SS amp, by the way the figures you cited represent a 100% change from .002 to .001. .
Lets suppose the SS amp starts at 0.1% THD and falls to 0.05% I would willing to bet this would be audible.
Plus in addition to this simplistic view of distortion the amplifiers IM distortion behavior when it is below its normal operating temperature has not been considered, nor has its behavior with regards to transient signals been examined. SS amplifiers are frequently not entirely stable before reaching their normal operating temperature. The amplifier might be ringing when reproducing transient music signals which would fail to be revealed if amp is only tested with a simple 1kHz sinewave. All of these factors must be considered when discussing SS amplifier performance cold vs warm. Of course the fact that all amplifiers are not identical designs must also be considered which pretty much rules out the applicability of any blanket statement about the cold vs normal operating temp. sound of SS amps.
Scotty
When in standby mode....don't most manufacturers run a certain amount of current through thermally dependent components to avoid/reduce the cold/warm distortions you mention?
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When in standby mode....don't most manufacturers run a certain amount of current through thermally dependent components to avoid/reduce the cold/warm distortions you mention?
Not really. Maybe a few but not many parts are covered, but then some are better than nothing.
Cheers.
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Not really. Maybe a few but not many parts are covered, but then some are better than nothing.
Cheers.
When you look at the standby power draw cited in specs of certain pieces...somethings getting heated! :icon_lol:
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Hi Steve
That explanation on warm up that i don't want to quote is excellent. It also gives a good feel of how some designers try and push the envelope in feedback to get as much out of their designs as possible especially in the higher freq neg global feedback that blow shit up.....lol
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Marketing Basis of Break In....
Customer: Hey, this doesn't sound better in fact I can't hear any difference.
Manufacturer: You need to give it more time to Break In...you'll be "amazed" at how the soundstage will suddenly blossom after 4000 hours!!!
Customer: But I already have over 4,000 hours on it!
Manufacturer: Ok, 8,000 hours then.
Sorry, couldn't help myself. :lol:
--Jerome
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KnowTalent,
When in standby mode....don't most manufacturers run a certain amount of current through thermally dependent components to avoid/reduce the cold/warm distortions you mention?
Posted on: Today at 07:53 PM
I agree with Steve on this one,I wouldn't count on it.
This complicates a design for a minor advantage in sonics, plus it uses up the designers budget and may cost you the benefits of what the designer could have built if he hadn't had to the spend the money on the standby circuitry.
If I had to chose between mute circuitry on a preamp or amp for protection against power interruptions and a standby mode,I will pick the former.
Scotty
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Customer: But I already have over 4,000 hours on it!
Manufacturer: Ok, 8,000 hours then.
Sorry, couldn't help myself. :lol:
--Jerome
yes, I know it was juvenile of me but face it, if you've been in this hobby for long enough chances are you've had a similar conversation at least once :icon_lol:
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When you look at the standby power draw cited in specs of certain pieces...somethings getting heated! :icon_lol:
Read my previous post again. I think you misunderstood what I posted.
Cheers Know.
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Hi Everyone-
I wanted to give you a heads up on how most soft-start power circuits operate.
When a TV, VCR, amp, pre, etc.. has a remote turn-on option there are two power supplies and usually twp power transformers involved.
When a unit is on standby, the main circuit has absolutely no power going to it. What receives power is the remote control circuit which is connected to the IR or RF input sensor. When the unit is powered on, a relay closes the circuit between the main power transformer and incoming power. This activates the rest of the amp/preamp/etc... When in sleep mode, everything except the remote circuitry is completely without power.
History: In the 60's, Motorola made a color tube TV which kept the filaments on when in "standby" mode. The result was a tube television which turned on instantly when the power button was pulled out. Yes, it did turn on faster than an 80's SS TV! :o
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I am sure moods make some difference but does not explain what actually happens to a component during warm up. Since not much university scientific information has been presented, I thought I would expand on such for better understanding of heat related/warm-up concerns.....etc.
Thanks Steve, the only sensible thing posted so far. This explains warm-up issues in SS components in a concisely worded fashion (re. simple enough for us dolts to understand). And it explains why leaving my components always turned on results in a more stable audio presentation. Now to the rub, how would one differentiate between warm up and break in, with break in being a permanent physical change to either a cable or component on the micro or macro level and warm up being the repeatable condition you describe? For example, when we install a new cable or component we generally turn the system off for a period of time, cooling the system down. When turned on are we hearing the system warm up, the component break in, or a combination of both?
As an addendum, how long can warm up last? An hour, a day, a week, the mythical 4,000 hours noted previously? When first turned on from a vacation period etc., my system sounds as harsh and brittle as a newly unboxed piece. Of course it settles in after an hour or two, but if left on for 24 or 48 or 300 hours, it continues to smooth out. And yes KT and turkey et al, it can certainly be my hearing that smooths out, but my question is there continued changes in thermal stability as the component ages over longer time periods?
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Warm up is the process where the device as a whole reaches its average operating temperature. Typical warm up time is around a hour. It takes time for heat to spread from components which generate it to ones that do not.
When a components heats up, there are changes in how it conducts electricity. These changes disappear once the device cools back down. Nearly all electronic components change properties after they heat up. There can be audible changes after an amp/preamp/etc.. heats up.
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Warm up is the process where the device as a whole reaches its average operating temperature. Typical warm up time is around a hour. It takes time for heat to spread from components which generate it to ones that do not.
When a components heats up, there are changes in how it conducts electricity. These changes disappear once the device cools back down. Nearly all electronic components change properties after they heat up. There can be audible changes after an amp/preamp/etc.. heats up.
In simple terms it's called Heat Soak.
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Warm up is the process where the device as a whole reaches its average operating temperature. Typical warm up time is around a hour. It takes time for heat to spread from components which generate it to ones that do not.
When a components heats up, there are changes in how it conducts electricity. These changes disappear once the device cools back down. Nearly all electronic components change properties after they heat up. There can be audible changes after an amp/preamp/etc.. heats up.
So I take it you are saying there is no "Scientific Basis of Break In" and it's all warm up in the first hour and misguided perceptions after that?
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I never entered into the break-in subject. My response was specific to the warm up period of electronics.
I think what you want to know is whether temperature cycling can change a component's properties over a period of time. Yes it does and it typically leads to replacing the effected component due to material fatigue in extreme cases.
The best way to proceed into a good discussion regarding how something can change over time or temporarily (aka: warm up time) is to ask questions about specific components. That is because the answers will be different for resistors, capacitors, etc..
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Ethan, you are just throwing numbers around with the change in distortion vs.the operating temperature of a SS amp
If you believe those numbers are not realistic, let's see your actual numbers as measured on a competent SS amplifier.
the figures you cited represent a 100% change from .002 to .001.
Yes, but who cares if neither level of distortion is audible? I'm sure I already made that point.
Lets suppose the SS amp starts at 0.1% THD and falls to 0.05% I would willing to bet this would be audible.
Maybe, maybe not. 0.1 percent puts the distortion 60 dB below the music. That's awfully soft. Plus, aren't you now "throwing numbers around" too? Are you guessing, or have you actually measured those numbers? You say "willing to bet" but are you really? If you're willing to visit me in person we can easily do a test like that using any source you'd like, to see at what levels you can hear distortion come and go.
As an example of a competent but not state of the art power amp, let's use the Crown PowerBase 2 amp I bought back in the early 1990s. This is a serious professional amplifier made by a serious company that knows what they're doing. This amp puts out more than 350 watts per channel into 4 Ohms with less than 0.05 percent THD and IMD. The specs provided are pretty detailed, as is common for pro quality gear, and there is not one word about anything changing over time as the device warms up. There is a note with the specs that I found interesting:
At Crown our published specifications are guaranteed for three years. Further, because our "in-house" specs are more stringent than our published specs, every Crown amplifier will exceed its published specs.
If this amp changes quality over time in an audible way, I'd be very surprised. I've certainly never noticed that.
Plus in addition to this simplistic view of distortion the amplifiers IM distortion behavior when it is below its normal operating temperature has not been considered, nor has its behavior with regards to transient signals been examined.
Not been considered by whom? The average audiophile? I'm sure all of this and much more is considered by competent amp designers!
SS amplifiers are frequently not entirely stable before reaching their normal operating temperature.
I'm too lazy to type more quotes from the Crown manual's specs, but there's an entire long paragraph about output stability, lack of turn-on transients, protection against thermal runaway that Steve mentioned, and so forth. If you have any hard evidence to support your claim that competent SS amplifiers are "not stable" for [who knows how long] I'd love to see it. Not theorizing, or speculation on what types of distortion have or have not been measured, but actual hard data sowing an audible change over time longer than maybe 3 seconds.
Look Scotty, even if it can be shown that competent SS amplifiers change audibly over the first 1-30 minutes of operation - and that's never been shown to my satisfaction - the fact remains that the main reason some people perceive a change in sound is due to their own changing perception. That's the core issue here, and it's the reason discussions like this appear again and again and again. We can hypothesize all day long about what changes occur inside an amplifier as its temperature rises. But if those changes are never actually audible, it's just an exercise in mental masturbation.
--Ethan
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the fact remains that the main reason some people perceive a change in sound is due to their own changing perception.
Ok, some sounds reasonable. Differences in design, masking effects from components, room, expectation bias against perceiving differences, etc can account for why some perceive no change.
Would you be kind enough to provide evidence that only one specification, harmonic distortion figure, can support your claim that your example of an amplifier is superior to others? Thanks Ethan.
(In the next paragraph, the higher the negative feedback signal, the higher the negative feedback ratio, the closer the feedback signal amplitude is to the actual input signal amplitude (except it is 180 degrees out of phase at midband. High feedback ratio may be for one volt input, .9 volts or higher may be fed back from the output to the input. This means more stages are necessary for a given gain with feedback applied, and more effects from warmup which affecting multiple parameters.)
Suppose we use extremely high negative global feedback signal (also called an extremely high feedback ratio) for Ethan's example of .001% harmonic distortion. We now apply an input jack signal at time point "A". Extremely high feedback signal "B" typically arrives back at the input jack 6-12 microseconds (us) late with respect to time point "A". This alters the waveform and sound since human hearing is sensitive to 5us changes, Jneutron sources say 2us. (known for decades, and high frequencies affected more than lows). These parameters are also affected by warmup as well.
Next, very high feedback signal "B" reappears at the amplifier output again, (only slightly lower amplitude because of high feedback ratio) and on the input jack a second time, this time 12-24us delayed from original time point "A", so the waveform is altered even more. Of course waveform distortion affects the high frequencies far more than the low frequencies and is not measured by a distortion analyzer.
So although extremely high negative global feedback appears very good on the surface, we simply traded harmonic distortion figures for another form of distortion. Now if we lower the feedback ratio, this waveform distortion lowers while harmonic distortion rises. So we are simply lowering one form of distortion while raising another.
We can hypothesize all day long about what changes occur inside an amplifier as its temperature rises. But if those changes are never actually audible, it's just an exercise in mental masturbation.
The changes in warm up parameters of components are scientific and well understood for many years. (Sources, late 60s college, and the RCA Radiotron Designers Handbook, 26 engineers, 4th edition, addresses the subject in 1952.) No one appreciates your negative mis-characterization that we are simply "hypothesizing. :nono:
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In general to all, the danger of pushing "audio perception" testing to the for front above measurements is that it is an inexact science, and companies can simply pick and choose which tests to use for marketing purposes. It is also well known that audio testing is easily manipulated to a conclusion of no sonic difference (especially by those associated with big business/inexpensive companies for marketing purposes/public opinion manipulation).
This allows big business and/or low cost manufacturers to falsely claim "all amplifiers/preamplifiers sound the same" which of course is absurd due to different designs, different parts/quality affecting the sound etc.
In the end it amounts to marketing tatics reigning at the expense of science.
I hope this post meets the guidlines since it is standard main stream science, just as my previous posts are. I really don't see the need to post again since lots of evidence has been presented concerning warmup and sonic changes, and most of the material has been covered.
Cheers.
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Does anyone here believe that a capacitor can take 400 hrs to "break in"?
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I have had electrolytic caps used for coupling caps to block the DC on the output of a single ended class A buffer take a long time to break in and fully form. The voltage biasing them was 2volts and the ac signal was less than that. Four hundred hours is about two weeks time and I am certain it took at least that long in my case for the cap to stop changing. I would say the time for break in to occur would depend on the cap construction and applied voltage. I have no problem accepting that in some cases people may be able to hear changes in a caps impedance curve after voltage has been applied for some period of time.
Scotty
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I have had electrolytic caps used for coupling caps to block the DC on the output of a single ended class A buffer take a long time to break in and fully form. The voltage biasing them was 2volts and the ac signal was less than that. Four hundred hours is about two weeks time and I am certain it took at least that long in my case for the cap to stop changing. I would say the time for break in to occur would depend on the cap construction and applied voltage. I have no problem accepting that in some cases people may be able to hear changes in a caps impedance curve after voltage has been applied for some period of time.
Scotty
Troubling. I have heard of designers who select caps by ear--physically swapping them in and out of a circuit in real time (e.g. Shindo, D. Wilson). Perhaps they remove those caps from burn in boards, powering the board down just long enough to remove the "formed" caps and then inserting them into the circuit being tested before the caps "re-form"? Sounds painful.
In your case, if the caps are left discharged/shorted after "forming" for a long time do the curves return to the "before" curve?
I wonder what a small change in the impedance curve of an ac coupling capacitor sounds like. I suspect that the difference between an electrolytic and a non-polarized cap might be larger. Has anyone done this particular experiment?
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I agree it sounds like a pain in the butt. I tested three electrolytic caps a BlackGate,Ruycon ZL and a Panasonic FM.There was a clear progression towards a cleaner window,with the FM cap being the clearest view of the performance.
The differences in sound between the caps were not subtle.
Scotty
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I agree it sounds like a pain in the butt. I tested three electrolytic caps a BlackGate,Ruycon ZL and a Panasonic FM.There was a clear progression towards a cleaner window,with the FM cap being the clearest view of the performance.
The differences in sound between the caps were not subtle.
Scotty
Interesting. Subtle or not there's a number of flaws with your methodology.
A subjective perceptual test in which the size of the subject pool is one is not statistically valid, and the test itself lacks the proper controls. So your test really doesn't prove anything meaningful. Put a control group in, and increase the size of the subject pool, stick to a scientific protocol, obtain the same results, and then you may be onto something.
This is where these discussions always wind up, with neither side budging. I mean c'mon folks, it isn't like this is the first time that this topic has been brought up in the past 20 or so years.
In response to Ethan, the reason that no one has been able to point to scientific research that follows the proper protocols with the required controls is because there isn't any. I don't know why that's the case. Perhaps the questions that are of considerable interest to audiophools are not substantial enough to merit the attention of independent researchers. Or perhaps the answer to these questions really doesn't benefit society at large, and with limited resources there are more important questions that need to be answered. And perhaps it is because audio manufacturers are reluctant to help fund independent studies...because while they could win they stand to loose, and loose huge.
I don't know that audible break-in does or does not occur. I believe that in some devices, such as speakers and phono cartridges, it does...and in other devices, such as amplifiers, it does not. Earlier this year I spent several thousand dollars on a new speaker system, and initially I was very unhappy with their sound. I thought the bass response was too boomy and the highs were a little too bright. I did not have a lot of placement flexibility but the vendor did work with me to try to tune the ports and the compression driver. I was having a tough time with it. The vendor offered to take the speakers back if I wasn't happy, but I really wanted to give this more time and a fair chance to work. Eventually the sound of the speakers began to improve on their own. I don't recall how many hours were on the drivers at that time but if I had to guess I would say it was somewhere around 150 hours. Did the performance of the speakers change because of break-in? I think it did but I really don't know that for sure. I do know that I am now very happy with my speakers and I think they sound great. But for all I know what took place over those 150 hours was that the speakers didn't really break in, the listener did, and all that really happened was that I became acclimated to their sound.
--Jerome
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Interesting. Subtle or not there's a number of flaws with your methodology.
A subjective perceptual test in which the size of the subject pool is one is not statistically valid, and the test itself lacks the proper controls. So your test really doesn't prove anything meaningful. Put a control group in, and increase the size of the subject pool, stick to a scientific protocol, obtain the same results, and then you may be onto something.
This is where these discussions always wind up, with neither side budging. I mean c'mon folks, it isn't like this is the first time that this topic has been brought up in the past 20 or so years.
In response to Ethan, the reason that no one has been able to point to scientific research that follows the proper protocols with the required controls is because there isn't any. I don't know why that's the case. Perhaps the questions that are of considerable interest to audiophools are not substantial enough to merit the attention of independent researchers. Or perhaps the answer to these questions really doesn't benefit society at large, and with limited resources there are more important questions that need to be answered. And perhaps it is because audio manufacturers are reluctant to help fund independent studies...because while they could win they stand to loose, and loose huge.
I don't know that audible break-in does or does not occur. I believe that in some devices, such as speakers and phono cartridges, it does...and in other devices, such as amplifiers, it does not. Earlier this year I spent several thousand dollars on a new speaker system, and initially I was very unhappy with their sound. I thought the bass response was too boomy and the highs were a little too bright. I did not have a lot of placement flexibility but the vendor did work with me to try to tune the ports and the compression driver. I was having a tough time with it. The vendor offered to take the speakers back if I wasn't happy, but I really wanted to give this more time and a fair chance to work. Eventually the sound of the speakers began to improve on their own. I don't recall how many hours were on the drivers at that time but if I had to guess I would say it was somewhere around 150 hours. Did the performance of the speakers change because of break-in? I think it did but I really don't know that for sure. I do know that I am now very happy with my speakers and I think they sound great. But for all I know what took place over those 150 hours was that the speakers didn't really break in, the listener did, and all that really happened was that I became acclimated to their sound.
--Jerome
What is really sad is that the scientific community itself doesn't appear to agree on proper protocol and controls by all the arguing going on over the years. And you will hear every excuse in the book including how they are the real scientists etc. Check the association of authors to sponsors, employers, associations (and those sponsoring them), etc who perform the "scientific" tests. It seems to always be about swaying public opinion/marketing. :(
Cheers.
ps. Oooops. I am bowing out.
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The reason I chose those two cable geometries is that they are in common usage in the audiophile community and people within that population would agree that they sound different from one another. What defines an abnormal geometry when it comes to audio ICs is something I can't answer. The pundits say that DC to light bandwidth is not necessary in a cable carrying audio band signals. I think the two examples I gave would fall into the realm of adequate for audio signal transmission.
I'd say that coax is normal for an unbalanced RCA-RCA patch cord. The two you describe have no shielding, and are probably what I would describe as abnormal.
Yes, I know you specified twisted pair for one of them. Unfortunately, twisted pair doesn't work with an unbalanced connection where you don't have a differential input stage. But I'm sure you already knew that.
I would think the chance to learn something new about yourself and your system would be compelling enough to get you try the experiment.
I really don't see that playing with wires is a good use of my time. It's just not a pressing issue IMO. Been there, done that, etc.
The last time I listened to wire was on a system with expensive Gallo speakers, Audio Research electronics, a very expensive turntable and cartridge (I didn't pay attention to the brand names because I'm not into LPs at all anymore), and a Meridan CD player. There were power cords that looked like firehoses, CD demagnetizers, Bybee gizmos, etc. All the goodies.
He said he had upwards of $40K in his system, and he works in the business, so I think we can assume that his system was "resolving."
I didn't hear any difference between OmegaMikro wire and some Zu Audio wire of more normal construction.
I've done controlled tests of wire on enough systems, and with enough different people to conclude that the big differences people report in in sighted tests simply don't exist.
The construction phase of the cables would take longer than the listening test session. You stick the cables in and you hear a difference or you don't. The differences between the two should easily be gross enough in nature that no SBT or DBT testing is necessary.
So one or the other of them has gross FR irregularities?
If you are not interested in the cable geometry experiment that's cool,frankly I suspect that if you do the break in test with couple a Shack patch cords you may not hear any difference. You may have a chance if you system resolution has
So Radio Shack patch cords are immune to "break-in?"
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Well, when you compare crap to crap, what else would you expect?
Are they crap because they don't cost a lot? Or is it because of the brand name? Just exactly what are you claiming here?
Do "crap" cables not break-in? Because the point of the test was to see if wire breaks-ins.
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Good point, face. A few posters here who come from a certain owner's circle feel that the point of this hobby is to spend as little as possible and then to sneer at those who would rather make an investment in truly high-end gear.
Ah, so you're that Bill person that hates Frank? I wondered why you popped up suddenly and started replying to my posts.
You should probably give it a rest, because I've said that I didn't hear a real difference between my AVA gear and a Pioneer receiver. I hardly think that qualifies me as an AVA cheerleader.
I feel that one should buy a good set of speakers, and also get their listening room into the best shape possible or practical.
From there, I would rather buy music.
I'm not sneering at your spending $100K on an amplifier or whatever. I'm just saying that, when I have done controlled tests, nobody could tell the "truly high-end gear" from a $200 AVR.
Ditto for expensive wire versus what some people here call "crap."
Actually, if you want sneering, look at the people who seem to think my hearing or the products I choose are "crap."
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Bruce Brisson of MIT has something to say about this in his recent Dagogo interview:
http://www.dagogo.com/View-Article.asp?hArticle=793
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In general to all, the danger of pushing "audio perception" testing to the for front above measurements is that it is an inexact science, and companies can simply pick and choose which tests to use for marketing purposes. It is also well known that audio testing is easily manipulated to a conclusion of no sonic difference (especially by those associated with big business/inexpensive companies for marketing purposes/public opinion manipulation).
This allows big business and/or low cost manufacturers to falsely claim "all amplifiers/preamplifiers sound the same" which of course is absurd due to different designs, different parts/quality affecting the sound etc.
I don't think I have ever seen any manufacturer of audio equipment claim that their products sound the same as another maker's do.
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Bruce Brisson of MIT has something to say about this in his recent Dagogo interview:
http://www.dagogo.com/View-Article.asp?hArticle=793
If his claim is true, it should be easy to measure. Too bad nobody ever presents any measurements to back up this claim.
One major flaw is that audio signals are AC, not DC. I guess 'ol Bruce missed that.
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This topic is now locked.
There is nothing like a friendly discussion going on here. The need by some members to impose their own viewpoint on this topic and others is causing me to reevaluate whether this Circle serves a positive purpose.