Burn in question and evaluation before burn in

I tend to avoid the type of gear that changes audibly. Manufacturers can design gear to be dramatically less affected by burn-in by simply designing it in such a way that it less sensitive to the things that do drift with use (capacitors, driver compliance for example).

Why don't you contact me via Audiogon. I see your comments here frequently and you seem to think caps and break in are a bad thing.

I can give you the name of the designer/ manufacturer that builds ALL the current hot caps that are on the market, sold under a dozen different names.

He will tell you break in is not only real but important. YES, it effects the sound greatly and if you think you can design around this, you are missing most of the great equipment on the market today.

I never said break in was not real. I just prefer components that are engineered to be precise and that do not drift dramatically with time. It is a simple design choice to place a capacitor in the signal path or not.

And it's a simple choice to provide the finest capacitor available in the best equipment and that means IF you have a cap, it's a VERY high quality cap, it will take a VERY long time to break in.

It is a simple design choice to either place a capacitor in a passive crossover (where it adds distortion) or use a line level x-over filter.

I use an active crossover with my speakers but they were designed that way from the start. To say it's a simple design misses some very important points. To execute an active crossover properly you need a separate amp for each frequency. I agree that's the best, but to call it simple is inaccurate. Such a design generally requires a lot more parts, amps, cables and space. Not every designer (or every customer) is willing to do this.

That leaves us with caps inside the crossover, a design that represents most of the speakers out there, yours and mine perhaps the exception. Regardless if the caps are inside (my) active crossover or in a passive design, they play an enormous role in performance and ALL great quality caps take forever to reach 100% performance.

There is no design exception to this unless you have system with no caps.

My point was to simply challenge the idea that burn-in that sounds greatly different is a good thing . It often implies overly simplistic designs that are commensurate with a goal of "purest signal path". Unfortunately, the engineering reality is quite the opposite - through added design complexity one can dramatically increase precision and robustness of product performance from changes in temperature, ground loops, cables, interconnects, power, noise, component aging etc.

I think every designer in the business would agree with that and most would say they worked to achieve that goal and provided same for their customer, within the limits of budget given for the project.

Rodman99999, thanks for the link.

Maybe designers will provide enough data over time that "tech" minded audiophiles will accept the fact that with current technology it's impossible to design caps that don't have "sound."

Caps used in critical positions in high end audio combined with a careful listener means the effect is huge. Most high end manufacturers have upgraded caps steadily and frequently over this last decade. It's a technology that's literally exploded with innovation and improvements.

I think we also agree that it is not safe to assume that everything out there is designed properly and burn-in is necessary for many designs.

If that single criteria were used to assign quality to high end audio components, most or all of the best available would be termed "improperly designed," by that Douglas Self proclamation.

I'm excited by the improvements of the last few years from Dynaudio, Aesthetix, Audio Research, CAT, BAT and other companies that have embraced the latest high tech cap design. Many of the newest and finest pieces contain caps made by a guy that's a friend in the business. These caps are sold under a dozen names, made to different performance standards depending on budget.

I know of no contributions from Mr. Self that rival these designs, In fact he's probably one of those that think Radio Shack, Cardas and Nordost wire all sound the same with no audible effect on a high end system and the music it produces.

Wenrhuang, regarding break in process and what to expect. There are no set in stone results available where performance can be spelled out. Too much variation in parts and systems.

IF I had to guess (and this is a guess), considering the type of upgrade and the fact it's a transistor based design, I imagine right out of the box the sound was OK, but perhaps a bit compressed with slightly sloppy bass.

The music turned to shrill with poor bass after perhaps 20 to 50 hours and if it does prove to be superior to the original status (before your upgrade) it will not completely smooth out until about 450 to 600 hours.

You can accelerate the process by turning the preamp on and feeding it signal ( FM, CD, or whatever) 24 hours a day for a couple of weeks. That should be close to 400 hours by then.

The amps and speakers need not be on and no requirement to listen to music during this time unless you want to. I would love to hear a report if you choose to do this experiment. The electricity used will be less than the shipping cost to return the preamp and you might learn something.

Wenrhuang,

Please read my post, the one above yours. Also, regarding:

I am also curious that is it, and how is it possible for a burn in to go in opposite direction in different stages? That is, for instance, for system to becoming brighter at one stage, and then become darker at another stage?

This is not uncommon and not far off what I posted before you said the system seemed to be headed in a more positive direction.

Unless you have a lot of hours, be prepared for it to go wrong again before it gets right. I know this seems improbable, but mirrors my experience in many situations.

Most aplogies and breakin stories come from people who have chosen poorly and can't deal with the awful truth (I've been there myself).

Dave, are you saying break in is not real?

I have a break in story, my Dali Megaline speakers were so bad when I first got them that members of my group said I could not "fix them."

Now they say I have the best sound they have ever heard. It did take over 800 hours before they stopped changing. Bass was NON existent in the beginning and I mean absolutely non existent.

If my story is rare, lightning strikes multiple times. Audiogon member and good friend Louis (Logenn) experienced the identical thing with his Karma Exquisite Enigma's.

As with my system, multiple people (about 20 in our group) visited both homes and listened and reported on outcome multiple times.

Some of these visitors listen only once every two or three months, some once a month and some once a week or more often. Considering the huge difference in equipment, solid state, tubes, electrostatics and cones among this group, to have everyone agree about the changes that happen with break in is pretty conclusive in my book.

Similar things with electronics, especially things that have big power supply and or high end caps.

I agree that some people change the personality of their system repeatedly by tweaking this and that. Entertainment value is about all that's good for. My goal is to try and remember every variation possible so I can correct things that are wrong with the system as I slowly upgrade over time.

A typical thing that requires adjustment is my new improved crossover, the Air Tight Supreme over the PC-1 and the Aesthetix Eclipse replacing my Signature models.

All these new items have potential to be better out of the box (as you state) but unfortunately they are not 100% right away. All the high quality moving coil cartridges I've had experience with require 40 to 150 hours before they sound their best.

I'm told by Aesthetix that the new Io Eclipse must be burned for over 100 hours before they can trim the RIAA accurately. Since that's done with an oscilloscope that should qualify as a true indicator of how much caps move after signal is passed through them.

I have found that gear which sounds off/not right/bad etc.., will not change enough over time to make it acceptable.

All I can do is refer to the examples I've already given. If you don't accept my experience as believable, that's OK. It obviously differs from the path you've chosen.

Thank you David, very well stated.

Maybe veering off from the exact direction of this conversation, but the way I determine break in is to drive the component 24/7 and do sample listening sessions every few days.

This is easy to do because I'm self employed and my photo studio is connected to the room where my system is.

The break in period I refer to is obtainable in little more than 2 weeks. If you've owned a system for several years and cannot keep track of changes over two or three weeks, you should not be discussing this topic.

For the record, I keep a pad beside the stereo when changes are made and record time. Then I have people in my group listening at least once a week with no coaching from me.

I find this is not only a good way to learn about changes during break in, it's also effective in determining the character of NOS tubes and every kind of tweak that's ever been thrown into my system.

I've learned a lot by including as many others as possible.