Break in period


I have just acquired the Conrad Johnson CT5 preamp and CJ LP70S power amp. Would appreciate inputs /advice of fellow a'goners regd optimal break in period and is the break in period dependent on playback volume or amount of
gain. The reason I ask is coz a Stereophile review of the CT5(July 2006 ?)mentioned that the preamp was left in continous play mode for a week, that translates to 150 hrs.Given that i listen max 2hrs/day and more on weekends, that translates to a break in period of nearly 2 1/2 months !!
Have huge issues leaving the system running 24/7 coz of erratic power supply and neighbour's privacy etc
Would appreciate any/all advice
Cheers
128x128sunnyboy1956
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.     
Due to thermal cycling and mechanical flexing, some components may change slightly. I would not lose any sleep over this.
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 ?
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).
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.
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, 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?
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.
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.
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...
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.
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.
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.
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.
+++ 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
A bit harsh, Paul.

It is my impression that even inexpensive gear benefits from break in.
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.
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.
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? :-)
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!
Who's talking about lemons? Good grief.

(Now I'm doing it. Best find another thread.)
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.
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. :-)
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!
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!
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
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
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, your second paragaph is dead on. Yes, let's agree to disagree. Sorry I overreacted earlier. Dave
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 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
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.