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

Maybe so it's too late to return it?

Having two ARC pre in two different systems, one bought new (17es) and one bought used (LS 27) but with only 200 hours on it when I received it, both with factory papers and both showed a recommended 600 hour break-in.

While the LS 17 does not have a hour counter, it is well over two years now so I would venture that is is well over the 600, and as noted by others, the pre started to open up becoming more defined as the hours mounted. The 27 has just started to increase soundstage (everything else remaining constant) and a slightly annoying high end has smoothed out.

I understand some of the theory, superstition and black magic behind this need for 600 hours, but if we accept the same for interconnects, speaker cables and ac power cables why not tube equipment? I regularly start up everything early in the day and do not attempt to listen until much later allowing everything to settle in producing background music as I go about my day. I have never been dissapointed at the end of the day when I really want to listen to some music...just my .02

anybody can build their own gear

anybody can read a textbook on cognitive psychology too (well, ok not everybody...)

I agree it would be hard to measure a change - tho one could arrange a blind listening test to show an effect w/o knowing any mechanistic reason for the effect
but...
if ARC says to do something, why not do it?

for my ARC pre-amp it warms up for about 40 seconds - could be tube protection tho, not SQ

"A skeptical open mind is always a good thing."

Interesting how a skeptical mind is often at odds with the open mind, no?

@dchang1981

I do believe this is possible, but not common. It needs time domain measurements, patience and LOTS of data.

Audio measurements are too often really simple things. Steady state sine waves, sweeps, square waves. There are a lot of tests which go ignored or under used. I'm not saying I have proof, but I am saying I think a good data scientist/engineer could eventually discover.

For instance, in speakers, dynamic range/compression is rarely tested by magazines, but it's one measurement I find describes a great deal of what I hear. Perhaps some day I'll come up with cap sound measurements and they'll name it after me. :D :D

But proof, no. Experience, somewhat. I'm not really interested in forcing the issue on anyone though. A skeptical open mind is always a good thing.

Best,

E

you're telling me that sophisticated measuring equipment wouldnt show a change to demonstrate what you are describing as bloom or whatever audiophile terminology you want to use?

To Randall-11

I have lots of practical and theoretical, working in the Aviation world in avionics, I also am a certified Machinist and fabricator. I have rebuilt and restored many audio units, reel to reel recorders, tape cassette, amps, preamps, etc... Designed my own gear, built many varieties of cables and so forth. 
But you may have known that if you actually read the post rather than breeze through and develop your usual assumptions and then criticize others. 
For those of you who cant build their own gear, the lack of real experience tends to make you more prone to believing whatever sounds most convincing or has been kicked around in forums here and there. 
You can speak with the moderator about your comments, they know about them and so do you. Have some respect and manners speaking to members.

 
dchang1981
just show measurements that demonstrate a change after burn in then i'll be a believer.

How do you measure soundstage, grain, bloom and warmth?

just show measurements that demonstrate a change after burn in then i'll be a believer.

what was the insult darkmtter?

No one can deny that Nelson Pass is an expert, and the experiments prove him right.

Or are you a science denier?

Authority is not as good as an on point experiment but a LOT better than an ill informed opinion?  If you don't believe that then do your own surgeries and find out.

Actually, an expert in court provides expert opinion or evidence, not proof. See the difference? Besides an expert can be wrong, his testimony doesn’t guarantee success for whomever he is testifying. And experts don’t always agree. That’s why the defense expert witness often disagrees with the plaintiff expert witness. Hel-loo! That’s why the Appeal to Authority is an illogical argument.

To Randy11

Who do you think you are insulting members? Like you own the forum, or are vastly superior in intelligence than the rest of the members? 
Make a positive, beneficial comment or dont at all if you just want bash people. 

DM

Make two reasonable assumptions.
That there is some of legitimacy to the notion of "getting accustomed to the sound" burn in.
There is probably an element of the circuit undergoing real physical changes "during/over use" time as well.
Thus there is perceived 'burn in.'   QED....  EOD...... 

randy-11
Nelson Pass IS an Authority

Exactly! That’s why it’s an illogical argument. An argument cannot be won by simply claiming to be an expert in the field. Besides, amplifier designers disagree on many things. I'm quite sure I can come up with another terrific amp designer who disagree with Pass.

Nelson Pass IS an Authority.  But he is simply stating what numerous experiments by cognitive scientists have shown.

But ARC made their amp and can advise you best -- even if listener subjectivity is an effect, that does not rule out teflon caps needing some time.

Also, as ARC how long they listened to your unit - they listen to every unit they make not just a sampling.

Excellent advice- Ray (rspyder).
Happy Listening!

It's the massive teflon capacitors that need the break-in time.  I have a ARC Ref 10 preamp and I know it can be an agonizing process to wait for the full blume and potential, but as others have said its well worth the wait.  I can honestly say, having listened to and owned many other preamps, the ARC Ref 10 is the best I've heard (after 600 - 650 hrs of break-in).  It's within a hair of the VAC Statement that costs over twice as much as the Ref 10.  Hang in there your patinece will be rewarded. 
Ray

Georgelofi wrote,

In response to this, "burn in" and "being out of adjustment" are not the same.

If you know better convince Nelson Pass of this below, in case you missed it.

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."

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."

Classic case of Appeal to Authority. I.e., just because someone deemed to be an authority offers an opinion on something doesn’t necessarily mean it’s true. One actually doesn’t have to look too far to find a designer of audiophile amplifiers or whatever who has stated he has some sort of issue with break-in/burn-in of amplifiers, cables, capacitors, wiring, fuses, wire/fuse/cable directionality, polarity, or anything else related to audio. In fact, if I may be so bold, amplifier designers might be the most dogmatic of the bunch. No offense to Mr. Pass or anyone else.

I think the notion, differences and understanding of "burn in" are pretty misunderstood form reading many descriptions.

If everyone realised that "burn in" has so many factors involved that it should be broken into sub categories of "break in" rather than "burn in",  perhaps getting a better idea of what is expected from it might be easier to answer? 

I know when I buy a new piece of gear or replace a capacitor I call it "break in". A new piece of gear that has been used for some time is "broken in" but also well "burned in". 

A new piece of gear that has been broken in and burned in for some time and needs say a few new capacitors because of failure is still burned in but needs to be re-burned in again because the new capacitors will take about anywhere from 10-100 hours to break in and reach their final burned in sound. The gear as a whole is still burned in just the capacitors will keep changing sound until they get to a certain point. Break in generally refers to getting a part or gear to certain point of aged reliability through a controlled break in of parts. Not all parts can go to 100 percent full on from new and have to be slowly broke in or premature damage could result from over heating or sudden stress. Metallic parts are heat treatable so too fast of or hard of break in can actually change the way a part ages or takes to being able to predictably get past the final "burned in" point. 

There is a point where different electrical parts take longer than others to get to their "optimal state" from new. And then from that point they are degrading slowly and steadily. The sound may change for better or for worse. It is a combination of experience and parts that dictate this.  

One good example of this is Cables. A cable only has the variables of the wire and dielectric. A little more straight forward from a "burn in" point of view. 

Most speaker, power, interconnect, etc... are not "broken in" because they have a near zero failure rate, have no electrical parts and ultra high consistency in sound out of the box. They are just used to transfer electricity or the source signal. So here we can refer to where I believe many confuse the two, "break in" and "burn in".
They similar but different as the burn in is only really changing the surface and magnetic field of the wire and dielectric. So because these attributes change the the conductor so does the sound for the reasons I stated in the original post I made. 

So hopefully this makes as much sense to you as it does to me? ;)

DM

In response to this, "burn in" and "being out of adjustment" are not the same.

If you know better convince Nelson Pass of this below, in case you missed it.

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."

__________________________________________________

Yes of course these are factors in any piece of gear, but where do most manufacturers draw the line? Nelson Pass is an exceptional designer of both consumer and professional gear, but this isn't explaining what burn in is? 

He is also doing this because he knows that on occasion a small percentage of parts "drift" from their values quickly and are by their standard out of spec, not necessarily anyone elses spec. 

I have built and repaired many pieces of gear and always take readings of the values of for example capacitors and resistors, they can be so close to spec for dozens or even hundreds in a row and then all of the sudden so far from spec. This is why all good manufacturers burn in their products and do a final analysis of specs.
They know from experience the parts failure, drift and burn in time rate that is expected. 

Quoting Nelson Pass doesn't make your description any more accurate than you previously stated, that is his procedure for meticulous production standards which are seldomly done by any in the field because final costs of products get pretty high. 

Nelson has set the bar pretty high for himself and can't be caught with his pants down so going to those lengths of "burn in" is beyond what is burn in. It really making sure his product has satisfied his standards to not get back a piece of gear for component failure within the warranty period or even much longer. This is so far above most others ethically alone that it is a personal over financial gain that few choose to go to.

Think about what "burn in" really is again in the real world in everyday use products.

DM 
 

In response to this, "burn in" and "being out of adjustment" are not the same.

If you know better convince Nelson Pass of this below, in case you missed it.

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."

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

"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 
*******************************************************
In response to this, "burn in" and "being out of adjustment" are not the same. When a unit reaches burn in doesn't make it out of adjustment and requiring new setup from a technician. The components may be aging but this is a good thing. Everything reaches its optimal state of age and for most electronics it takes a long time to consider them not good. Generally I think under 100 hours is the most you should expect to break in a large variety of components. The amount of "current" can play a role as well. 

In fact how a unit sounds after break in is a planned part of prototyping to final design. All electrical parameters are set to reach this "break in sound". 

During break in an electrical effect happens, the flow of the electrons across all of the components causes micro surface arcing and tends to smooth and create a shortest route pathway. There is also a small magnetic field that develops around all paths which affects signal flow and interaction between materials.

To give you a visual idea, all this happens over time like water flowing through a pipe that had very fine sand in it. The effect smooths and polishes the edges and surface of the pipe, to electrons at an atomic level it also aids in flow. The flow of electrons can be a violent one, if they "carve" themselves the optimal pathway noise decreases and more of the original signal is heard. 

My passive pres work right away. Just kidding, I have many others which need break in!

My passive pres work right away. Just kidding, I have many others which need break in!

>> "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." <<<

I think you are confusing 'warm up time' with the process of 'burning in - breaking in.'  Warm up time may take for you 5 minutes and is how long it takes for a component to stabilize after turning on.  Burn in time different, and is a transformation that takes place that causes a component to reach its design potential. Its like breaking in a new car engine that can take hundreds of miles.  Its not to be confused with how long it takes an engine to warm up before running.

Its not just ARC equipment. I was told by a modifier who replaces mediocre components with high quality ones, that quite often the best ones take longer to break in. Now, if I could not hear it for myself? I would call it marketing BS. But, what ever it is that takes place to burn in a component? No one has yet to find the science to show what actually takes place. In the mean time, the fact remains that something takes place, and is discernible. I have witnessed to it too many times to doubt is a real phenomena. Its possibly something takes place on the molecular level that no one yet knows how to measure for. When there are electrons, voltage, and current moving through resistors, capacitors, switches... wires, etc? Who knows what changes it causes? Our ears will know its a real phenomena if our system has the resolve and transparency to demonstrate it.  

After my philosophical bs, 
Let me agree re tube amps! 

"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."

agree. Air, bloom and soundstage are MIA until later on, after an hour for sure. This is the sort of thing that apparently separates the mid fi troops from the rest of us.

In the final analysis all we can listen to is manipulated power. But it is manipulated power,  be certain of that.
Is it even possible to listen to precisely the same signal every time, even if we wanted to?
Conversely could we possibly hear marginal differences, even  if we wanted to?

Warm up is fine for correct bias to be reached and dc offsets to stabilize.

From new first power up, a few hours are fine for all caps and components to form.

But 600hrs to reach optimum sonic ability is shear voodoo, and as has been said it's just "expectation bias" or as Nelson Pass calls it " burn-in of the listener"

Cheers George 

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.

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

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.

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.

"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

"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

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.

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

" 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.

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.

"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

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

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."

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

 

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

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

" 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