06-16-14: Zd542
I have some Cardas cables that take forever. 100's of hours. ZD, as I'm sure you realize I have great respect for your experience and your sonic perceptions. But a question: How do you know that the improvement you are perceiving after 100's of hours is due to the cables, and not to something else in the system that has changed in the meantime? Or, for that matter, something that has changed in the AC power, or even the temperature or humidity of the room? My question is prompted in particular by reports I have seen here from others about cables and power cords requiring seemingly absurd burn-in durations, e.g., 800 hours or more. Unless, and perhaps even if, that is done independently of operation of the system, such as with a cable cooker, or in a different system, or by using a power cord to power a refrigerator, etc., I don't see how any such changes can be distinguished from effects that may be occurring elsewhere in the system or its environment. And even if the burn-in is done via one of those alternative methods, given that 800 hours represents more than a month of 24/7 operation, it would still seem very possible that some unrelated effect might occur in the system or its environment in that period, that could be responsible for the perceived change. Best regards, -- Al |
As I see it, it can be expected that by the time developmental testing is completed on the prototype of a new design, including final tweaking/voicing of the design, the prototype is likely to have accumulated a MUCH greater number of hours of operation than production units accumulate prior to leaving the factory. Both as a matter of necessity, due to the nature of the development process, and because the designer will want to assure that final tweaking/voicing takes into account any possible breakin phenomena.
Therefore if in fact breakin phenomena occur for a given design over a number of operating hours that is greater than the number of hours of operation of production units prior to shipment from the factory, those phenomena will continue to occur after the component is placed in service by the end user. And the component will not perform as its designer intended until after some period of use by the end user.
I would be very surprised if any of that were not the case, particularly when it comes to speakers, cartridges, AND major electronic components. So I am in essential agreement with ZD on this point.
Regards,
-- Al |
ZD, thanks for the thorough response. I will say that when it comes to reports of phenomena that are difficult or impossible to explain, I would have a good deal more confidence in yours than in those of many others, who often seem to not consider the possibility that the perceived change may be caused by something other than what is being assessed.
George, thanks as well for the inputs in your two posts. All I can say is "wow," to both of them.
Best regards,
-- Al |
06-18-14: Bifwynne
What are your views about electronic gear? FWIW, ARC maintains that its gear requires a considerable amount of break-in. FWIW, my instinct would be to consider their recommendations as credible, certainly for their own products. Tubes, capacitors, and (I suspect) transformers and transistors, and perhaps even resistors, can be expected to change their characteristics to an audibly significant degree during some period of burn-in. To a greater or lesser extent depending on the specific circuit design, the specific parts that are used, and on how much testing and burn-in is done at the factory. There must be a lot of material science going on here that is way over my head. As far as cables and power cords are concerned, is it possible that running current through the cables and cords in some ways affects the metallic crystalline structure?? That is a serious question? My feeling is that it's over everyone's head, in the sense that all kinds of explanations can be hypothesized, one of them being dielectric absorption effects which are commonly cited, but given the difficulty or impossibility of establishing (either analytically or empirically) that a given hypothesized explanation is great enough in degree to have a reasonable chance of being audibly significant, any such hypothesis is unlikely to be either provable or disprovable. Which is one reason why: 06-19-14: Mapman
... its pretty much the wild wild west where anybody can claim anything at anytime with no substantiation and get away with it perhaps. +1 Best regards, -- Al |
George & Peter (Csontos), I would respectfully disagree with what appears to be the logic behind your recent posts, at least with respect to electronic components (amps, preamps, digital sources, etc). It seems to me that implicit in your logic are the following assumptions:
1)The alleged breakin phenomena which you dispute would result in changes that are measurable, at the component level (as distinguished from the piece part level).
2)As long as the component measures within the +/- tolerances defined by its specifications it will sound as the designer intended, meaning that it will sound the same as his or her prototype sounded when its development was completed.
3)Therefore for the alleged breakin phenomena which you dispute to exist, the component must measure outside of the +/- tolerances defined by its specifications when it is delivered to the customer.
In the case of electronic components I see no reason to expect any of those assumptions to be true.
Regards,
-- Al |
George, what I was disagreeing with were the three assumptions I listed that your disagreement with ZD appeared to be based on. As far as my own beliefs are concerned, I think we are all agreed that speakers, cartridges, and tubes will change their behavior significantly as they break in. Beyond that I cant particularly speak from experience, as the only major components Ive bought new in many years have been speakers. But since youve asked, FWIW my beliefs concerning other kinds of components, and cables and power cords, are as follows:
1)I have made the point in dozens of threads over the years here that it is extremely easy in audio to attribute a perceived change to the wrong variable. And I believe that many reported perceptions of changes due to break in, especially those involving many hundreds of hours, are the result of incorrect attribution, made possible by experimental methodology which is not adequately thorough and disciplined. Of course, I also assume that in a significant number of cases such reports are simply the result of misperception. And all of that is fostered by a goodly amount of what I perceive to be mythology and technical misconception that is pervasive in audio.
2)Concerning electronic components (solid state as well as tube), as I said I cant speak from experience. However, a considerable majority of those audiophiles whose opinions I have come to particularly respect, and who also have vast amounts of experience with excellent equipment, believe based on that experience that new electronic components generally require a breakin period of at least tens of hours, and in many cases hundreds of hours. While my technical background and my understanding of how this stuff works does not enable me to precisely explain that, it also does not provide me with any definitive reason to refute it. Therefore I believe that solid state and tube electronic components can be expected to undergo significant amounts of breakin, perhaps several hundred hours for some components.
As I implied earlier in the thread, however, my strong suspicion when I see reports of 800 or 1000 hours or thereabouts being necessary is that either there has been a misperception, or something else has changed in the system or its AC power or its environment (e.g., temperature or humidity, as we both cited earlier in the thread).
3)Concerning cables and power cords, I would say that Im somewhere in the skeptical part of the spectrum, but I dont completely rule out the possibility. Among various explanations that tend to be offered, effects related to the dielectric, such as dielectric absorption, are perhaps the most commonly cited. However I have never seen any QUANTITATIVE analysis or measurements offered which would either establish or negate the possibility that such effects may be great enough in degree to have a reasonable chance of being audibly significant. It is very easy to conjure up explanations when they are not, or as a practical matter can not be, subjected to quantitative scrutiny.
The bottom line: As with most things in life, I believe that the truth depends on the specifics that are being considered, and generally lies somewhere in the middle part of the ideological spectrum.
IMO, YMMV, FWIW, etc.
Regards,
--Al |
06-23-14: Georgelofi
So it seems like we are in agreement, that to us "break in" for better or worse can occur with the mechanical devices such as speakers drivers, cartridges, and tubes, as you also said.
And you and I will not commit without skirting around the edges and state to "break in" periods of semiconductors or active components can get "better sounding" with said "break in" times of 100's of hours, unless some technical proof is brought forward, forgetting hearsay of friends and customers. George, that is not quite what I said. Note particularly item no. 2 in my previous post, which is entirely consistent with what is stated in the references ZD cited just above. Peter (Csontos), the potentiometer-related effect you described certainly strikes me as being plausible, and a clever observation, but my suspicion is that it is just one of a great many effects that can occur. Best regards, -- Al |
