Break in period

Look into Blackgate capcitors. This is something I have saved. I have Blckgate caps in my Denon 5910 plus other little goodies. The unit sounded great at 500 hours and it was not done cooking. 1000 hours and another blanket was lifted from the speakers. I am sure equipment varies in break in period but It happens and it can happen in a big way.

It can take many hundreds of hours before the maximum sonic benefits can be heard in audio circuits that use Black Gates. This long settling-in procedure is often a controversial issue when auditioning such equipment, as the frequency responses will tend to shift around greatly during this period - making the equipment sound different from one audition to another. Once completely 'burnt-in' however, the benefits can be heard clearly.

Black Gate is made by Rubycon Corp. of Japan.

Shadorne, your second paragraph comes close. If you like the sound of lets say, Dynamicaps, and decide to use them when you build or modify an amp, they will change ever so slightly the first few hours of use. That is irrespective of your design.

However, this is not necessarily a lengthy process nor is a frustrating one. Dynamicaps do most of their settling within 4 hours or so, and I always get a big kick out of hearing the very subtle improvement as I spin the first 6 to 7 LPs. It’s almost like watching your child getting born, only less costly. Makes all the soldering worthwhile.

Tone arm wire and step-ups take forever to burn in. This is due to the very low voltages going through them. (< 0.005 volt in the case of many MCs). I put them on my cooker and run 2 volts through them for a few hours. Believe me, they’re well burned-in after that.

More than likely the stuff you bought were run for a few hours at the factory for shake down tests. That would all but run-in most components inside your gear.

Regards
Paul

If I may "explore" Shadorne's comments above, we may find similarity rather than disagreement:

My point was that audio engineers [would aim to] design things to sound consistent and significant audible changes ascribed to [any number of parametres, one of which is] lengthy burn-ins (after months of listening) (...)[may] not be very desirable [since it could result in performance variations between otherwise identical pieces of equipment]

.
I wouldn;t think anyone is doubting that -- if I catch Shadorne's drift.

The fact that there IS some change in performance is all the more interesting.

A note about wires, referred to by Atma above: one of the most boringly annoying such situations must be changing the tonearm wire. Once changed "for the better" the new wire often takes an PIA time to "settle"/burn/break or whatever it is or takes for it to sound normal/itself...

Shadorne, your second paragaph is dead on. Yes, let's agree to disagree. Sorry I overreacted earlier. Dave

Paul,

My point was that audio engineers design things to sound consistent and significant audible changes ascribed to lengthy burn-ins (after months of listening) is not very desirable.

If I understand you and others, you are saying that this has nothing to do with choice of material or circuit design but is the intrinsic property of most wire and most of the electrical components typically used; a lengthy break-in, lasting several months, being unavoidable and independent of the design or material choices.

I can't see how to reconcile these views - so I propose we agree to disagree. As I am blessed with tin ears, I am blissfully unaware of these minute changes and simply can't imagine how frustrating it must be to be able to hear them. I tend to think of Edgar Allan Poe Usher family type thing ;-) Admittedly this last remark being a bit of hyperbole - for amusement - no offense intended.

Shadorne, are you saying that engineers deliberately engineer their equipment to audibly burn-in? I have heard some far out theories before, but this one sets new standards.

+++ Often the part selection and design criteria are heavily influenced by the desired products useful life span. +++

Mmm yeah. This statement would have been even more interesting if there was any correlation between burn-in and reliability/life-span. There isn’t, but if you are theorizing that there is, then we have yet again set new standards for far out theories.

+++ Nobody wants a "lemon" out there that hundreds of customers complain about; the cost to make a manufacturing recall to get equipment to perform properly as originally specified to customers; the cost to reputation +++

Well it’s nice to see you’ve done Business Management 101, but again this has zero relevance to the phenomenon of burn in.

I guess you may find individuals that will send back V-Caps because they sound slightly better after 400 hours. Personally I elected to keep mine ... each time.

Regards
Paul

It is the transformers that require a long time to break in.
If you run a source and preamp to an amp that is turned off your neighbors will be happy and the preamp breaks in.

pipedream

Hi Shadorne, you are in fact absolutely right. . . there is almost a feeling of ancient magic to the hobby. . . . Some of it, perhaps like break in -- may be in part due to things our instruments have still problems measuring, as well as to the occasional minor dose of placebo effect. Other matters, like astute small clocks, aledgedly precious, semiprecious, or river-polished stones smack of neo-keltic rites and audiophilic-druidism. Next October at the AudioFest in Denver I should organize a grand sacrificial cerimony to propitiate onto us Audiana--sister of Gaya and great goddess of sound. Does anyone have a virgin piece of audio electronic whose yet unfulfilled life they would like to render into a burnt offering for the benefit of all of us? The cerimony would be very powerful and moving. . . lots of brilliant pebbles, Quantum dots, Clever Clocks of all makes and sizes, hypertweeters. . . . . . assurances of links to the mother of all web effects. . . the sacrificial Lamm all decked in audio finery and tied with audiophile-grade hempen twine to a brass audio isolation rack donated by Virtual Dynamics which keeps resonating like a tuning fork. . . and after we eliminate all stray Doppler effects, and we optimize the cloning of all its quantum states. . . replaced all its fuses with slugs of the best copper-Beryllium alloy, plugged its power chord into a 220V outlet, we will chant a final invocation and will throw its power switch. . . for an instant of firy and ecstatic break-in!

I am rather enjoying your astute game

Glad to here it. This hobby should be enjoyed!

These forums are consistently bombarded by fears of significant detrimental effects on the sound quality; (jitter, cables, break-in, warm-up, house electrical wiring, power cords, interconnects, speaker cables, gaps in digital waveforms, clocks, transports, etc.).

I often find myself trying to point out that many of these fears (of detrimental effects) are greatly exaggerated out of all proportion. This climate of "fear" is unhealthy, IMHO, as it distorts what is important from what is relatively insignificant, and, even worse, all these fears may intefere with what is absolutely critical: to sit back and enjoy the music!

Jeez, I think you are all too harsh. My impression of Shadorne is that, far from spreading mischief, he is coming at these discussions from the perspective of an engineer heretofore unexposed to (or unpersuaded by) the esoteric beliefs of high-end audiophilia. He's being stubborn because it doesn't make sense to him. Why not gently try to persuade him instead of decrying him as a bad element (my term, but that's the vibe I get).

I swear, sometimes it's like being amongst a group of creationists who don't want any "wrong-thinkers" in their midst. Run 'em out on a railroad, boys! The difference being that creationism is entirely nonsense, whereas at least some of what we believe around here may have merit. :-)

Offense? That would be a little difficult Shadorne. I am rather enjoying your astute game of raising false targets, logical decoys, examples out of context, subtly corrupted induction steps, . . and projections of wishful thinking a priori of reality.

Who's talking about lemons? Good grief.

(Now I'm doing it. Best find another thread.)

Dopogue says,

Shadorne has missed few opportunities (in the related posts I've seen) to repeat his break-in-is-all-in-the-mind nonsense

It is your prerogative to believe that it is all nonsense.

Dopogue adds,

It clearly takes a lot to penetrate HIS mind...

...the frustration in trying to keep him from spreading this mischief

Thankfully, you and many others do a great job of limiting the mischief I am causing!

Harsh but not unduly. Shadorne has missed few opportunities (in the related posts I've seen) to repeat his break-in-is-all-in-the-mind nonsense. It clearly takes a lot to penetrate HIS mind (changing his mindset is obviously not in the cards) and the frustration in trying to keep him from spreading this mischief can become quite palpable. Right, Paul? :-)

Drubin. I suspect that all gear is subject to burn in. However, I have little experience with inexpensive gear and as such would be silly to argue against someone that has.

I am also somewhat amazed as to why you equate the phenomena of burning-in to something that is deliberately engineered?

I assure you that engineers do have to worry about these kinds of things when designing equipment and not just the performance of the device on the day it leaves the factory.
Often the part selection and design criteria are heavily influenced by the desired products useful life span. Nobody wants a "lemon" out there that hundreds of customers complain about; the cost to make a manufacturing recall to get equipment to perform properly as originally specified to customers; the cost to reputation.

A bit harsh, Paul.

It is my impression that even inexpensive gear benefits from break in.

+++ No respectable engineer would deliberately design an amp with a significant drift in electrical response characteristics over 100's of hours +++

Really? Are you an engineer perhaps?

I am also somewhat amazed as to why you equate the phenomena of burning-in to something that is deliberately engineered? That is quite absurd. I replaced couplers in many-many amps. I most certainly did not do it to create the burn in phenomena – that is just a function of the cap I used – but I have almost always witnessed the caps settling down/burning in.

Simply because the bottom-of-the-barrel, cheap crap components used to manufacture Sony, Pioneer, Denon, Yamaha etc. does not exhibit this behavior, does not make them superior nor does it make their designer more 'respectable'. I can assure you, the Sony, Denon, Pioneer etc. engineer doesn't give a rats ass if his component is subject to burn in or not.

I opened an Onkyo DVD some time back and had electrolytics for coupling caps that probably retail for less than 1c each. Sure, you won't hear them settle in. They sound crap before settling, and equally crap afterwards.

I replaced the couplers in said Onkyo with $5 (yes, 5 bucks) worth std BG 16v 47uF caps. The owner is now beside himself at the improvement. And yes, he did notice the BGs burning in over the first 100 hours also, but I can assure you it sounds a lot better than the stock unit and then some.

Because your equipment does not exhibit burn in does not mean it doesn’t happen ... my $9.99 transistor radio also did not burn in. (Does that mean it better than my Audionote?)

Regards
Paul

Shadorne, if I get your comments right then I agree with them 100%. I feel very much that all components have their place and application.

Component stability (I would think) is as important in audio as in any other application. To that end one of the things that we really tried hard to do was to make our amps and preamps stable enough that even bias settings were only a very occasional adjustment. For tubes thats a big deal, and considering we make OTLs- well, the first thing we had to overcome was the idea that OTLs were unreliable.

At any rate, we got through all that but for whatever reason, we experience break-in phenomena all the time. What we have found about it is that it has *absolutely nothing!* to do with component or circuit drift. Nor is it some sort of illusion that is created in the mind- its very real. I think I mentioned earlier that some of the break-in effects are measurable too (and what some of them were).

Oddly enough, non of the effects seem to have anything to do with the fact that we use tubes. We have clearly seen what happens as capacitors 'form up' in the power supplies, what we've not been able to determine is exactly what is happening elsewhere although the evidence is pretty good that a lot has to do with wire. We have very little evidence that points to resistors, but we don't use non-precision parts either.

So bottom line is if I had to state what causes break-in, it would have to be filter capacitors and wiring.

The components' tolerances can affect the de-emphasis; many of the ("good")resistors used are +/- 5% i.e. 10% total rated shift...

Just a clarification for others reading the thread (not a correction);

These are manufacturing tolerances between individual lumped elements such as a resistor. These figures do not represent the amount of thermal drift, drift with aging of the component. These values are not necessarily indicative of the accuracy of an amplifier.

However, if you were to simply change a resistor without finding a resistor with a very close match to the existing resistor then you could expect a sudden change in circuit response of this kind of magnitude.

Guidocorona,

A kryton is an example of a high voltage application of a tube that is all; an application where a tube is a more reliable device than a transistor. I was trying to qualify the meaning of my previous comment of "low voltage applications" where transistors are often the cheap and preferred choice for designers.

Sorry if I offended you. Perhaps you missed the thread, which might explain the side track comments. I fully agree krytons are not related directly to audio applications. Although I suspect you will admit that reliabilty and response drift over time/heat/use is of concern in many electronics applications and not just audio. An undesirable response drift being analagous to extremly lengthy audible break-in time.

I am not sure what Krytrons have to do with the price of wheat in Alaska, or with audiophile-grade audio or even Radio Shack-grade audio electronics, for all it matters. Krytrons, made by EG&G or Perkin Elmer are high precision / high voltage switching tube-devices best known for their use in parallel honeycomb configurations when firing the chemical detonators that implode Plutonium 239 triggers of fission/fusion or fission/fusion/fission warheads. And trivially speaking, it is perfectly true that Krytrons are expected to fire precisely on spec the very first time they are activated. . . which is often their last time as well. . . no break-in planned, or allowed. So what? There seems to be a logical fallacy here somewhere. . . It is being contended that if for all electronic circuits, there exist at least one electronic circuit which can be built to fire completely on spec within 1 picosecond on first activation, then the same property must be inherently extensible to all electronic circuits. This is sheer nonsense. What we are discussing is whether for all electronic devices, there exists a subset of such electronic devices, digital, solid state, or vacuum tubed, which a significant portion of this audience extensionally deem to be high end audio gear, which tend to exhibit inherent and audible break-in patterns no matter how 'well' they have been designed/constructed/tested.

Drubin notes

the system was on, playing in the background. At one point during the evening, I began to notice extraordinary detail and elegance from the system. My brother noticed it as well. The amp sounded great!

Well, yes. The circuit will stabilise under normal operating conditions, as you yourself noted earlier

it's that individual circuit components (resistors, capacitors, wire perhaps) undergo some change during the initial hours of their use

However, you go on to note

This may not show in measurements but I think most of us agree that measurements alone do not the whole story tell

Not the whole story -- but some of it. Measuring the complete circuit during operation (DON'T really do this, for goodness sake :)-- I mention this only in discussion context) you may discover things... One easy component to track down is a phono equaliser. The components' tolerances can affect the de-emphasis; many of the ("good")resistors used are +/- 5% i.e. 10% total rated shift...

Drubin,

What I was trying to say was that designers will try to minimize the effects of individual resistor, transformer, capacitor & inductor drift due to age and thermal effects. Where a component is critical then a designer may choose to use a higher quality capacitor for, for example. Balanced circuits are an example of this approach. Feedback loops are also used to minimize drift.

Atmasphere,

'low voltage applications' - do you mean like phono signals

Actually I meant in general run-of-the-mill electronic industry applications, as transistors are not very reliable for high voltage applications where for example krytrons might be used (although transistors have got better at high voltage over the years).

I know you don't like negative feedback but I am sure you will at least agree that feedback is the electronics industry "cheap and easy" solution to achieve better linearity with high speed transistors. A high quality tube (much more linear than a transistor)with less negative feedback and more carefully selected components is another alternative approach, which works too (some say better for audiophile applications).

I didn't mean to trigger a debate of tubes vs SS (apologies if it sounded that way) all I really tried to show was that engineers favor configurations that produce consistent results (i.e. minimize response drift whatever the cause). IMHO, significant break-in response changes over long periods are not desirable and that good power supply and component designs should minimze these issues, in many instances to the point of inaudibilty under a variety of conditions.

Shadorne, I wonder if you might clarify this statement:

This is just one of the many reasons that modern electronics designers mostly use SS amps with feedback for low voltage level applications (tubes are still used in some very high voltage applications).

'low voltage applications' - do you mean like phono signals?

Let me say I could give a story about an amp that on one speaker sounded very good, and horrible on another, until it played thru the other speaker for about 25 hours, and then it started to settle and play as if it was matched well.. Why? It could be as simple as everybody seems to want to argue, it has to do with the Load change, A 4 ohm speaker that plays down to 20 hz, vs. a 6 ohm speaker that only responds down to 37 hz might in fact cause a Different HEAT and load in certain bandwiths bringing the amp to use a Different and measurable electrical difference after burning it in... Litterally maybe the components Quite simply do Adapt to the different impeadences of the Preamp, or the CD player, Or the Tubes, Or the Speakers that one link to the other connects too..

This could also show why some say the best matches out of the box are from the same Manufacture connecting to each other as they were all designed in one very common domain of parameters to each other... So you take a Audio research preamp and hook to a Krell amp, well maybe those caps, transistors or Whatever are Working harder or easier to a different load and at some point they almost adjust due to simple heat and current driving the unit... I mean some Preamps seem to have better gain and bass hooked to a certain amp, or speaker right? Well its just possible there is a little varience and things do start to run and kinda Burn in to that electrical response over time?

I mean I have no idea if this could be true, or if any manufacture has measured something Running 100 hours on their own stuff and then Running it on something that is less compadable and finding the synergy match to move a little over time.. I know it sounds a little crazy but why not?

Kinda like how When you use PRemium gas in a car for 3 months that should be using Plus gas and then you go back to plus and things are not quite right till the computer re-adjusts..Yes this is not the best example but gets a point across...

Or how a Plasma screen sits in a position for a prolonged period of time and Burns the image of a video game ghosted into the screen or something, I mean we know this stuff can happen, so its possible this is part of what people start to hear if not using factory matched components, or speakers not voiced to certain amps whatever...

Just throwing it out there, although I am not backing this as true. But it seems to make some type of possible sense.

Shadorne, you keep talking about drift in response, but I don't think that's the issue here. It's not that the design is unstable and therefore faulty, it's that individual circuit components (resistors, capacitors, wire perhaps) undergo some change during the initial hours of their use. This may not show in measurements but I think most of us agree that measurements alone do not the whole story tell.

I have told this story before, but it merits repeating. Back in about 1979, I got a brand new DB Systems DB-6 power amp in for review. Back then, break-in was never discussed as far as I know and it was not part of my audio consciousness whatsoever. I unboxed the amp and hooked it up (with zip cord) to my Quad ESLs. It sounded pretty poor. Oh well, the DB Systems preamp was quite good, I had higher hopes for the power amp. We had family over that night and the system was on, playing in the background. At one point during the evening, I began to notice extraordinary detail and elegance from the system. My brother noticed it as well. The amp sounded great!

This story is not evidence of the truth of break in (it could have been a power issue, or me getting used to things, or who knows what), but it was a defining experience for me as an audiophile (just as was my cycling through a number of different brands of receivers years earlier and puzzling over how different they sounded from one another) and has made me a cautious believer in giving a component some time when new before judging its sound.

so, the perception of a change in sound of a component is anecdotal and subjective.

Any electrical design engineer will tell you much the same thing. No respectable engineer would deliberately design an amp with a significant drift in electrical response characteristics over 100's of hours. A lot of design effort is spent ensuring reliable and consistent sounding products (feedback loops not only provide great linearity but also allow for much less variation in response to environmental conditions such as power supply drift/changes, age and temperature drift during warm up). This is just one of the many reasons that modern electronics designers mostly use SS amps with feedback for low voltage level applications (tubes are still used in some very high voltage applications).

Mrtennis

See my comment. Asked and answered.

i have spoken to a technician at Mcintosh. he asserts that for a tube component, after dissipation of tube impurities, the electrical characteristics of an amp or preamp will measure the same during the life of tubes. in the case of a preamp, 12 volt tubes last between 2000 to 4000 hours. power tubes may not last quite as long.

so, the perception of a change in sound of a component is anecdotal and subjective.

is it possible that since one expects a change in presentation during say, the first 300 hours that one will hear it ?

suppose one does not expect to hear any differences after 3 hours, when the impurities of tubes have dissipated. might it mean that no difference will be heard ?

how much is a placebo affect and how much is real ?

Due to thermal cycling and mechanical flexing, some components may change slightly. I would not lose any sleep over this.

I truly believe if and when "break in occurs" is basically you can kinda tell by the system just being more efficient and less congested sounding, whether turning up the volume or not.. Its got a looser feel to it, more detailed without feeling like your trying to push it out as hard.. This is my experience, now whether technical measured parameters can be prove on this or not is pretty much a pointless point. I have noted in the past there is a certain fluency that comes with a decent amount of hours on a system after time.. Cable break in is much less realistic, but in electronics a little can occur I feel, and definatley speakers I have heard become more fluent and intergrated with a better bandwith, now I guess if you measure a speaker for 20 - 20 without breaking in its all there, but some frequencys start to become more effortless and increase presence in time…

Why How or whatever reallly makes no difference to me, I mean I just don't get why this is such a Sin in audio to believe that such a thing can occur, No doubt its possible some systems simply sound great and maybe what one would think their best right away and they expect no more, but some can come into their own in time as well… Maybe its just you end up getting use to it, maybe cause all of a sudden your power company is supplying better power, and break in is just simply B.S. I guess some people look at this as an excuse for a not perfect performing out of the box design. So this is the only measurement I can give, if you feel 3 months later your system sounds more effortless and you don't think about it so much as to what you can improve, you have started your "Break in" period. Might happen for some, maybe not for everybody that has the sound they want out of the box already.     

After retubing of the PH5 with 4 matched 6922EH (purchased directly from ARC) the magic of the PH5 sound is still there, but i had to turn up the volume several clicks on my ARC-LS26 to obtain gain comparable to the old tubes--matched with the VS55 -- i have now about 35 hours -- is that normal ? VASILI

Gregm,

IMHO, although high damping factors is a "pushed" feature of SS amps....I think it is really over rated.

Frankly the driver Qes and Qms coupled with the box design almost entirely dominates driver response...above a damping factor of about 5 a higher damping factor really makes almost negligable difference to the driver response, as the voice coil and magnet size dominate the driver electrical damping. (A good speaker design should be as close to critically damped as can be achieved given a host of other compromises)

I suspect most differences heard with low damping factors are more related to frequency presentation, as a high output imepdance device acts as a filter when coupled with a variable load (speaker)....

Shadorne -- that mustn't be what I'm referring to. I distinctly remember them comparing distortion figures (3%) I think between two ATC models at specific spl levels...Oh well.

the higher output impedance of a tube (with ouput transformer) coupled with a typical bumpy speaker load. This results in a different frequency response/presentation from a tube/speaker combo versus an SS/Speaker combo

Normally, yes. But one thing that is important in a spkr -- and one thing we do NOT know -- is the strength of each driver's magnet. A very "strong" driver (e.g. a Lowther, etc) paired with a SS will be overdamped and sound like Donald Duck unless tamed (i.e. at xover level). A hi output impedance paired to a very strong (i.e. electrically damped) driver may provide the optimum marriage...

Methinks that they are hearing differences due to frequency response differences which are quite discernable even over 10%THD of the speakers.
Salut, Bob P.

Agreed. I expect you are referring to the higher output impedance of a tube (with ouput transformer) coupled with a typical bumpy speaker load. This results in a different frequency response/presentation from a tube/speaker combo versus an SS/Speaker combo.

Yes, Shadorne, I have always wondered how people can hear the difference between 0.002% THD on SS amps and 3% 'natural' harmonic distortion on tube amps over speakers with some 5-10% THD and sometimes up to 100% when the speaker 'doubles'! Methinks that they are hearing differences due to frequency response differences which are quite discernable even over 10%THD of the speakers.
Salut, Bob P.

Gregm,

I have a very old pdf of a paper that Billy Woodman published which explains his driver construction philosophy. It includes plots of speaker distortion and discusses IMD distortion and the advatanges of active versus passive designs. Unfortunately, speaker distortion measurements are pretty sobering stuff - I doubt most audiophiles realize the relative amounts of distortion coming from speakers compared to the rest of their gear. (Certainly not those who spend $4 K on speaker cables and an amplfier and only $1 K on speakers.)

Pauly

Did you measure distortion levels and how do you know it is harmonic distortions

Actually there is -or used to be- some ATC measurements available s/where re, linear & nonlinear distortion on their models. Unfortunately haven't found it-sorry. I do remember seeing this though... if you're actually interested.

Did you measure distortion levels and how do you know it is harmonic distortions?

I did not make measurements but harmonic distortion is quite easily recognized for its warmth, woody or resonant sound.

I doubt ATC would make a more expensive big box speaker used in studio mix and mastering with higher distortion at "loud" SPL levels as a modest ATC book shelf near-field.

I could be wrong though. Neither speaker sounded harsh ( telltale signs of excessive odd harmonics ) except at excessive SPL levels that were beyond rock concert levels.

All speakers introduce lots of distortion. Given similar quality in design/drivers, bigger speakers tend to play louder cleaner (a general rule for all speakers and not just ATC).

when I upgraded mains from ATC 20's to ATC 100's I actually had to make an adjustment to the reduction in harmonic distortion in the extreme LF at higher SPL levels.

ATC 100 have less harmonic distortion at LF at high SP levels than ATC 20? Really

Did you measure distortion levels and how do you know it is harmonic distortions?

Atmasphere,

Shadorne, are you saying IOW that you hear changes but you attribute them to yourself rather than the gear?

Often yes. Depending on the last time I had a cold the changes can be significant. Most often it is the result of focusing on something specific or different in a familiar repeated track. I suspect we get very accustomed to sounds and have a pretty good sonic memory (for example an actor's voice is instantly recognizable on a cartoon)...so changing a component as significant as a speaker can be quite disconcerting for several weeks as memory adjusts to the new way it sounds (versus previous familiar sound).

For example, when I upgraded mains from ATC 20's to ATC 100's I actually had to make an adjustment to the reduction in harmonic distortion in the extreme LF at higher SPL levels. Initially, it was disconcerting to me that a great big box speaker seemed to have less bass (but incredible clarity & punch) compared to a modest sized bookshelf with already a lean bass sound (compared to most fare). On the face of it, I had become accustomed to more bass warmth or harmonic distortion of the little driver when it was driven hard at higher SPL. (This effect cannot have been break in as the 100's were already well used).

Jeff sez

If the results are audible, shouldn't they also be measurable

Should be, I guess. BUT what would one measure? Once measured a diy phono equaliser with a friend (for other purposes) at ~2month intervals with a scope. Zilch.

Note however, that the caps had already been "treated" with a variac before they were mounted. Likewise with critical path resistors (components are important for the equalisation curve). Also, first measurement was well after first power up (a couple of hours or so).

Measuring break-in is not necessarily going to be very straightforward. You have to know what to look for. The basics don't change much. A lot of the obvious parameters measure the same before/after. That doesn't mean something hasn't changed. As Atmasphere mentioned, the best way to judge is by using your ears. It is quite apparent the change in many components.

The question is, what to look for? Let's take cables as an example. There is more than just RLGC parameters. Maybe the dissipation factor of the dielectric changes. Perhaps there is some contamination, impurity, or flaw in the refining or construction. I would look for the little things, like photoelectric, pyroelectric, thermocouple, electro-chemical processes, parasitic diode structures, etc. Copper-oxide is a semiconductor. It makes for a lousy diode. Dissimilar metals, junctions, crimps, solders, the list goes on. Could there be parasitic batteries embedded in a cable?

Note also, when a component undergoes manufacturing, it experiences many traumatic and often life changing events. Materials get melted, alloyed, refined, drawn, hammered, cast, extruded, gassed, separated, cooled, well you get the idea. Where exactly does the manufacturing process end? When the item has left the factory? Or when it has been conditioned and formatted for the application?

Examples? How about a battery? At least with NiMH and NiCd, you have to format them with an initial charge of 20+ hours. Really trickle it. If cut short, the result was a battery that would from then on hold much less charge. We did this test at Nokia, and a fully formed battery ended up with double the capacity. How about shoes? Don't they take a little time to break in? How about a violin? If a Stradivarius isn't played it loses its tone.

It might take more than a spectrum analyzer. But the answers are out there.

jh

Has anybody measured new components with, say a spectrum analyzer or similar device(s), and measured it again after break-in and published the results? If the results are audible, shouldn't they also be measurable (all other things being equal - easier said than done, of course)? Jeff

Shadorne, are you saying IOW that you hear changes but you attribute them to yourself rather than the gear?

Psychosomatic, huh? Or in other words. . . delusional, eh? And I thought that in 50 years of music I had reached a small modicum of insight. . . now I am really staggered by the harsh impact of factual reality!

Guidocorona,

I gave you a few brand names of a few consistent sounding, respected engineering and manufacturing firms (mass produced) that are well known reliable products. If, as you say yourself, your gear changes response or requires an extensive break-in of over 200 and up to 1200 hours then that would not be my preferred choice that's all. However, I don't agree nor would I dare suggest that your fantastic gear are just useless boat anchors or that you should dump your truck because of this. Peace. We probably have different interpretations of the differences heard from repeated playing of music. (what I call getting habituated or new insights from repetitive playing of music may actually all be "break-in", certainly I believe that ears/brain can be trained to become more discerning and repetition is a big part of it - so the listening experience is never identical)

Shadorne, I just don't follow what you are saying.