Why does it take so many hours to brea in arc preamps and amps?


I recently purchased a like new ARC 5 SE pre amp.  The unit had less than 200 hours on it.  Everything I have read states that ARC preamps take up to 600 hours to fully break in.  Why is this so and what improvements can I expect to hear as the unit accrues hours?
ewah
Let’s play with the "burn in" crews heads.

If you think about it, all the optimum adjustments are made at the factory after the amps been on for a while, maybe an hr if your lucky.
If thing change after 600hrs then those optimum factory adjustments have just gone out the window and need to be redone again.

So it’s either out of adjustment because of aging, and therefore not optimum, or the factory needs to have them on for 600hrs before they are adjusted and sent out to the shops.
Either way if things change they would be out of the original optimum adjustment.

Cheers George
"   what improvements can I expect to hear as the unit accrues hours? "

just sit back and listen for the changes yourself.     If members tell you what to expect then it takes all the fun out of listening to something new . 
Basically to make you think about it for full 600 hours till you realize...
Sound will open up and become more dynamic also bass definition will improve. Good luck.
They use tubes.

As to how long why not contact ARC?

BTW, they listen to every unit before it leaves the factory - and I think a single person still does all the final listening - yet another guy named Wendell from a high end audio co. in Minnesota - what's in the water over there??
It's generally put down to the time needed to break in the Teflon caps.

 I've had a Ref 2 phono SE for four years now and still only up to 391 hours ... and I'm not sure I can tell you if it's changing as over this long a timeframe lots of other things change as well. Put it this way if you don't like the sound of it at 200 hours (or for that matter at 20) it's not going to sound that different at 600
It took well over 300+ hours for my REGA Isis valve cdp and REGA Osiris integrated amp to settle in .... the actual burn-in process was longer but less pronounced farther out on the time vs performance curve. At 300plus hours, that timeline point was something of a common threshold that apparently is not unusual for many different brands.
Studies by cognitive psychologists show that sensory experience alters perception.

So, is it the tubes, the caps, or the listener?

"So, is it the tubes, the caps, or the listener?"

I would say an equal part of all three.

perhaps whoever recommends 600 hours break-in to any component except i guess car or boat, definitely doin' some substance abuse...
it might be either mushrooms or lsd.
My .02$, elements within tubes do change with use.   Frequently this is perceived as a diminution of harsh, hard, bright and othee unpleasant qualities. It shouldn't take a billion hours to get rid of this, sometimes only 60 hours, but more is typical oh let me say on average, oh just guessing,  for a typical set up maybe,  output tubes about 120, but please this is obviously highly highly variable.  Don't come back at me telling me this amp takes waaay more time or whatever. If your experience is different I would not be surprised.   
Two things. 1 tubes continue to change to some extent throughout their use, but usually reach a level sound.
2.  AND in ARC gear this can be very important.   You don't hear the tubes in certain circuits.  I had an ARC  pre and I  rolled 12AX7s in it couldn't hear any changes, tried a bunch of 5751s, same effect.
As for caps, That I don't know and of course  the circuitry itself ages. 
the only breakin time I worry about is with new speakers

I do think ARC tells you to warm their components up a bit for best sound, but it won't kill you to listen to an ARC pre-amp that isn't all the way warmed up


at least, it won't kill you right away
"Let’s play with the "burn in" crews heads.

If you think about it, all the optimum adjustments are made at the factory after the amps been on for a while, maybe an hr if your lucky.
If thing change after 600hrs then those optimum factory adjustments have just gone out the window and need to be redone again.

So it’s either out of adjustment because of aging, and therefore not optimum, or the factory needs to have them on for 600hrs before they are adjusted and sent out to the shops.
Either way if things change they would be out of the original optimum adjustment.

Cheers George"

I understand what you're trying to say here, but that's really not how it works. When a designer is building a new product and makes changes, the component gets broken in before they listen to it. For about 20 years now, I've been evaluating prototype's during the design phase for several manufacturers. I break in every piece of equipment they send me. Sometimes I'll see the same component 10-15 times as changes are made. That means I break it in 10-15 times.   
I've never heard anyone say that their component sounded worse after break in.  If break in is a real phenomenon, then statistically how is that possible?  Unless it explains why we constantly 'upgrade' to new gear.  What if gear only sounded good for 1-200 hours, and then it was all downhill from there.  Obviously, over very long periods of time component parts degrade and do need replacement.  But I would not call that part of "break in."
a lie told many times becomes truth.

V Lenin.
Most of my experience with break-in (as opposed to warm-up) is with speaker crossovers, and caps. Replacing a cap takes at least 24-72 hours for them to settle in and give you a "final" version of the sound.

I wish I understood the physics. :) I understand one hypothesis that is often stated as likely is placebo. I understand why it’s such a possible and easy answer but to me it’s not enough.

Like other things in Audio, it remains an area not fully explored. I hope someday there will be results that better explain what we perceive.

Best,

E
I’ll add transformers to my above post...

tho I have seen reviewers say the teflon caps.

The real question is what ARC says...

Anyway just leave the system on with a CD on repeat or something while you run errands, etc.


BTW, having a "long" break-in time isn't necessarily indicative of Teflon caps. I've had ARC gear that claimed a 500 hour break in with nothing fancier than Wima polypropylene caps.
I’ve had ARC gear that claimed a 500 hour break in with nothing fancier than Wima polypropylene caps.

ARC claimed this themselves in writing? Or are they saying owners report this.
I’d love to see where that’s written if they claim this.
If they did, they maybe playing on the "expectation bias" of customers so aptly named by Ralph (Atmasphere).

Cheers George
200 hrs will be a starting point for improved sound. By 400-500 hrs of listening time, one will hear where the time went in regards to continued sound improvement.  Teflon takes at least 600 hrs, more like upwards of 1000 hrs, to acheive optimum sound.  Sit back, relax and enjoy the journey.
Oh yeah, enjoy the Music as well.
Happy Listening!
When a designer is building a new product and makes changes, the component gets broken in before they listen to it.
I’m not talking prototypes, it’s production ones I’m referring to.
And the way your inferring is that the production ones are deliberately out of adjustment/calibration to factor in "break-in" period, which after those adjustment/calibrations are magically back in spec?? I think not.

To all those that say the manufacture has specified a certain "break-in" period, please link the rest of us to those manufacturers links, instead of it being just personal opinion.

Cheers George
@georgelofi

Yes, it was on a red warning sticker on the outside of the DAC 8. Well, not a sticker so much as a big red sheet taped to the outside. Clearly they intended buyers to see it before making up their minds. 

That DAC is long gone, and I had purchased a floor model from the local dealer, so I can't tell you if I thought that was real or not.

It not only claimed 500 hours for the DAC, but per input as well.

Best,

E
It not only claimed 500 hours for the DAC, but per input as well.

Sounds like Ralph’s "expectation bias" to me. By that time not only would a trial period be over but the warranty as well with some.

Still not advertised and written on a web page link by the manufacturer.

Just like the mains fuses that are "said" to have to be "broken in" and also to be 'directional" by manufacturers, yet try to find any of that advertised on a site by them.

Cheers George
" I’m not talking prototypes, it’s production ones I’m referring to.
And the way your inferring is that the production ones are deliberately out of adjustment/calibration to factor in "break-in" period, which after those adjustment/calibrations are magically back in spec?? I think not. "

How could you possibly get that from reading my post?

You have to have prototypes in order to get to production. Here's how it works. A designer puts together a prototype. Before he listens to it, he breaks it in first. Any further changes made to the unit under development, gets broken in before the changes are evaluated. The last prototype is the production model. Through every process of development, the unit gets broken in before listening to it. That includes the final production model. For example, if the manufacturer claims 500 hours for break in, that's the standard. So, when they sell an amp to a customer, the customer need to put 500 hours break in time on it. After that, the customer and the manufacturer have an amp that sounds exactly the same.

Also, I never inferred that production units are deliberately out of adjustment/calibration. What's to adjust? Break in is a passive process. I just don't see what's so complicated about all this. If you don't believe in break in, fine. Its an issue that will take care of itself over time regardless of belief.

How could you possibly get that from reading my post?


From this, as it infers that it’s in prototype stage. When a product is finalized there are no changes to be made once in production, as it’s all sorted.
When a designer is building a new product and makes changes, the component gets broken in before they listen to it.

And your talking 600hrs for each change in the prototype.
Any further changes made to the unit under development, gets broken in before the changes are evaluated.


Cheers George
Again, I'm not sure where you are getting this info from.

" And your talking 600hrs for each change in the prototype.
Any further changes made to the unit under development, gets broken in before the changes are evaluated."
600 hours? Where did I say that? I've never had an ARC product take that long to break in.

" From this, as it infers that it’s in prototype stage. When a product is finalized there are no changes to be made once in production, as it’s all sorted. "

You're stating the obvious. Besides, I already addressed that in my last post. The last prototype is the production model.

Since you want to go back to my "where did you get this info from" question, you're conveniently leaving out the portion of my post that's most relavent to the question.

" And the way your inferring is that the production ones are deliberately out of adjustment/calibration to factor in "break-in" period, which after those adjustment/calibrations are magically back in spec?? I think not. "

Show me where you got that from.

" To all those that say the manufacture has specified a certain "break-in" period, please link the rest of us to those manufacturers links, instead of it being just personal opinion. "

I just noticed that.

Ayre

Due to the manufacturing processes used for the wires, capacitors, and circuit board materials, a break-in period is necessary for the amplifier to reach its full sonic potential. 100 to 500 hours of music played through the system will ensure full break-in.

Theta

Getting to know your Dreadnaught D This Dreadnaught D has been put through a rigorous and unique testing procedure that ensures that it will last for many years with minimal service requirements. This procedure includes the following: •All assembled circuit boards are given a thorough visual inspection and are then tested in a bench-reference Dreadnaught D. •The tested, assembled circuit boards are then installed in a new Dreadnaught D and the whole unit is tested for every function and parameter. •The unit is put on a burn-in torture rack to test for any possible component failures. •It is then tested on an audio analyzer for all pertinent parameters. •The unit has all remaining chassis components installed and then undergoes a complete visual inspection, which assures that all Dreadnaught D’s meet visual specifications. •The Dreadnaught D then undergoes a critical listening and functional test. Burn-In Time While the Dreadnaught D amplifier will sound wonderful without any burn-in time, users may experience small sonic improvements during the first week or so of operation.

Burn-In/Break-In Time This unit has a break in period of about 1 week during which continuous improvement in sound quality will be observed. It is recommended that music be played continuously through the unit during this time to expedite the break in period.

Aesthetix

BURN IN TIME This unit has a break in period of about 1 month during which continuous improvement in sound quality will be observed.

There's 3 examples. If you want more just read an owners manual. Also, when you read through the Theta example, the break in requirements are different for Class D amp than traditional AB.

This to break-in or not break-in question pops up regularly regardless of the "object" in question; internal combustion engines, tires, etc. And there are always folks who argue against or for it. While there's some truth in the notion of the "expectation bias", there's no denial that physical (or chemical) properties of most electronic components changes as a result of going through constant temperature cycling. Some get better some get worse, depending on the piece in question. There is one fact that remains common - the longer a component is left on, the lesser it will last.
"
a lie told many times becomes truth.

V Lenin. "

Not always. After 65+ years of Leningrad, the Russians still remembered the name of their city was St. Petersburg.
rsv4, one lie is too many and there are many. some lies will and some won't be remembered and that's where the trick is.
While the Dreadnaught D amplifier will sound wonderful without any burn-in time, users "MAY" experience small sonic improvements during the first week or so of operation.
"MAY" this is a get out of jail card. Otherwise they would have used the word "WILL" 
It also infers "Expectation Bias"

The unit is put on a burn-in torture rack to test for any possible component failures
This test is for weak/faulty components under heat stress, not to "burn in" for better sound.


Cheers George
" To all those that say the manufacture has specified a certain "break-in" period, please link the rest of us to those manufacturers links, instead of it being just personal opinion. "  Georgelofi

A second to rsv4's previous post.

Quote from Ayre CX-7eMP owners manual:
"100 to 500 hours of music played through the system will ensure full break-in.

Due to the manufacturing processes used for the printed circuit boards, wires, and capacitors, a break-in period is necessary for the CD player to reach its full sonic potential."

Manufacturer's link:
http://www.ayre.com/manuals/Ayre_CX7eMP_Manual.pdf

Does this meet your criteria George?

Dave
Does this meet your criteria George?

I trust some things Charlie Hansen say’s, but sorry not this one Charlie. If this is so with this Ayre CDP, then the (break-in) needs to done at the factory, then all adjustments be checked and re-done if necessary at the factory, before it’s sent the store/customer.

But in electronics just a few of hours see new electrolytic caps that have sat on the shelf too long and such being "formed" (if you know what that means) to their best, if not they are leaky or too old and need to be replaced.

I believe in speakers, a "break-in" can apply "being a mechanical device" with roll-surrounds that need to bed in and soften up.

Cheers George
So now Charles Hansen is unqualified or just plain lying! You and Bo1972 are the Masters of the Audio Universe. Nobody’s buying it in either case.

Dave
dlcockrum
I put the SR Black mains fuse in my REL subs about a week ago and had to cut the output levels back at a good bit.  "Previous to the fuses, I could not enjoy low listening levels, the sound was just not rich and dynamic."
You and geoffkait need to get together and write a book on hifi voodoo.

Cheers George

 
This is just getting stupid.

" To all those that say the manufacture has specified a certain "break-in" period, please link the rest of us to those manufacturers links, instead of it being just personal opinion.

Cheers George "

If you read the info I have you, it was a fairly broad selection of break in requirements. Some list hours, some months, different types of equipment, no break in..... What more do you want? You're making an argument just for the sake of making an argument. Lets continue.

" This test is for weak/faulty components under heat stress, not to "burn in" for better sound."

I know. Do you know how I know? Because that's exactly what they say in the quote.

" "MAY" this is a get out of jail card. Otherwise they would have used the word "WILL" It also infers "Expectation Bias"

The get out of jail card and expectation bias. Now you really got me backed into a corner. How do you explain this?

" Burn-In/Break-In Time This unit has a break in period of about 1 week during which continuous improvement in sound quality will be observed. It is recommended that music be played continuously through the unit during this time to expedite the break in period. "

That's also out of a Theta manual, but for a different amp. Now what? You can't say I tried to trick you (although I don't think that would be too difficult), because I gave you fair warning. Here it is again.

" There's 3 examples. If you want more just read an owners manual. Also, when you read through the Theta example, the break in requirements are different for Class D amp than traditional AB. "

Now its my turn.

" I trust some things Charlie Hansen say's, but sorry not this one Charlie. If this is so with this Ayre CDP, then it (break-in) needs to be done at the factory, after which all adjustments re-done before it's sent the customer. "

What adjustments are you specifically referring to? I have that CD player. There are no adjustments to be made after break in. Not only on that CD player, but every CD player ever made. A straight answer this time. No BS.

" But in electronics just a few of hours see new electrolytic caps that have sat on the shelf too long and such being "formed" if you know what that means to their best, if not they are leaky and need to be replaced. "

OK, so now you are making statements on break in. Show us where you're getting that info from, and why is that statement correct while the vast majority of the audio industry is wrong? I hate to be mean, but look at it from out viewpoint. You have no problem criticizing designers like C Hanson and his peers, but they're the ones making state of the art high end electronics, year after year, and they're following increases. All you do is talk. See the difference?

Does that mean these designers can do no wrong and are faultless? Of course not. But you've shown nothing to support your case other than a will to win the argument regardless of what's actually true. What makes it even more sad, is that I've read many of your posts in other threads, and more often than not, I would agree with you on whatever topics were being discussed. Now when I read your posts, the first thing that will come to mind is, "read it a few times and see what his angle is."



OK, so now you are making statements on break in. Show us where you're getting that info from
Just Google "forming electrolytic capacitors" and be enlightened just a little. 

Cheers George
"You and geoffkait need to get together and write a book on hifi voodoo."

Better Geoff than a pompous flat-earther like yourself.

Get over yourself, everyone else already has.

Dave

Georgelowbrow wrote,

"You and geoffkait need to get together and write a book on hifi voodoo."

All you need to know is that a sufficiently advanced technology is indistinguishable from voodoo.
" Just Google "forming electrolytic capacitors" and be enlightened just a little.

Cheers George "

Once again, you have it completely backwards.

" But in electronics just a few of hours see new electrolytic caps that have sat on the shelf too long and such being "formed" (if you know what that means) to their best, if not they are leaky or too old and need to be replaced. "

Of course the caps need to be broken in, but your statement implies caps are the only things that need to be break in. Also, I find it odd that you only respond to some comments, and not others.

" I trust some things Charlie Hansen say's, but sorry not this one Charlie. If this is so with this Ayre CDP, then it (break-in) needs to be done at the factory, after which all adjustments re-done before it's sent the customer. "

" What adjustments are you specifically referring to? I have that CD player. There are no adjustments to be made after break in. Not only on that CD player, but every CD player ever made. A straight answer this time. No BS. "

Why can't you give me an answer on that? Your statement is very clear and direct. You should have no problem backing it up.

" To all those that say the manufacture has specified a certain "break-in" period, please link the rest of us to those manufacturers links, instead of it being just personal opinion."

If you refuse to answer some of the questions based on your comments, I think its safe to say its your personal opinion. I think its only fair that you hold yourself to the same standard you expect from others.



Nelson Pass
We burn products in for two reasons -

1. We want to see if anything fails.

2. We want to readjust the amplifier against any drift in performance
that comes with a burn-in.
And you can bet your life that’s not done after 600hrs!!!

Nelson Pass on "Burn In"
It's pretty clear that any such long term behavior is going to be
obscured by the burn-in of the listener. People come to new
audio components carrying the experience of the previous
equipment, and may experience some dissonance with the new
sonic character, even if they like it overall. Over time they often
get used to it and grow to like it.
There are plenty of cases where they initially like it, but the sound
becomes irritating over time. That is called burn-out.


Cheers George
Bob Crump (TG Audio/CTC Builders) was contracted by John Curl to design/voice the Parasound JC-1 monoblocks - based on the HCA-3500 amp chassis.

Break-in time with the JC-1s is horrible as it takes right at 30 days for the thinness to go away and almost 60 days for units to open up.

Curl thinks he has tracked down the severe break-in problem on the JC-1s to the high current Nichicon caps.

Funny, but some of the cheapest parts break in easier than the fancy spreads.......
This thread includes many of Bob’s comments. It’s an interesting read. No doubt, Bob would have a few choice words to add to this discussion. He wasn’t shy.

"Burn in" is a very different thing than "break in". Burn in usually involves temperature cycling from an extreme high temp to an extreme low temp in a controlled environment chamber using hot-to-ambient and ambient to-cold temperature ramps determined by an engineer. It is used to weed out early-life-cycle component failures (faulty components tend to fail early in their life cycle) and solder issues (cold solder joints) or instabilities in circuit performance due to temp variations. It is usually done with the unit powered on while software tracks critical electrical performance parameters over time during hours of repetitive hot/cold cycles. It is also known as "accelerated life testing" and is critical to ensuring consistent and reliable product performance in mission critical applications like the computers that run Wall Street, government communications/data storage, large internet hubs, etc.

How do I know this: 20 years of running business units/divisions that built thousands of mission-critical computing and networking products for IBM, Cisco Systems, Lucent, Nortel, Sun Micro, etc.

If all audio products were burned in this way, break in would be minimal as it would only require enough time for the temp to stabilize as the components would already have seasoned due to the accelerated life testing. They would also cost a hell of a lot more.

Dave
"Burn in" is a very different thing than "break in".

Nelson Pass still refers to them as the same in my last post, factory  "burn in" or listeners sonic expectation "burn in", take it up with him, if you think your more technically knowledgeable.

Cheers George
It might be best to take a deep breath and not worry excessively over break-in of components or cables, or speakers since most audiophiles are constantly upgrading or modding something or another. So the chances that anyone can actually determine how long a particular thing has completely broken in or ne able to track a particular thing's progress over 200 hours of playing music is rather remote IMHO given that the system is exhibiting constantly changing sound quality, both better SQ and worse SQ.

Even if someone is patient enough to hang in there for 200 hours or 600 hours, which I’m definitely not, the system sound can change for other reasons that break-in, external reasons like time of day, day of week, weather, or changes to the system, errors in the system, changes to house AC, etc. having said all that I am confident that it’s not expectation bias that explains why breaking in components, speakers cables and interconnects with the XLO Test CD break-in track played continuously for at least a few days, preferably two weeks, goes a long way to breaking them in.

Bob Crump used the MOBIE (Maximum Overdrive Break-in Equipment) break-in device on his TG Audio cables and interconnects for a number of weeks prior to shipping. I also used BOTH the MOBIE and TG Audio cables, which were spectacular by the way.
break in..........

break out........

burn in............

burn out..........

4 variables can lead to many combinations

and then we have ............................. warm up.

I have never come across a situation where the gear, and listener/s did not benefit from some warm up.

George,

Your posts speak for themselves. Knowledge as thin as a molecule of Graphene and reason one thousandth the thickness of that.

All of your challenges have fallen flat. Then the rapid degradation of your defensive retreat. What’s next, "Nuh-uh. You are!"

Dave

dlcockrum speaks the truth.

George, with all due respect, you seem to argue against common knowledge supported by facts...


Post removed 
I have yet to hear a tube amp that sounds as good after 5 minutes than it does after 1 hour let alone 4 hours. That I know for sure.
Currently explainable science be damned----and I love science.