Burn in question and evaluation before burn in

Mr W- I've had passive and active components that went through 4 or 5 changes in presentation before reaching stabilization. Some sounded ridiculous at times. Be patient(at least 200 hrs) before listening critically, and deciding whether you like the component's presentation or not. The best capacitors and cables use high grade dielectrics(ie: polypropylene/polystyrene/Teflon) that don't absorb/discharge energy as quickly. That means "burn-in" takes longer too. (http://www.national.com/rap/Application/0,1570,28,00.html) Also look at the paragraph about Dielectric Absorption here: (http://www.sbelectronics.com/application_notes/cterminology.htm)

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.

Exactly!! =8^)

I think we are in full agreement about capacitors - see what Douglas Self has to say;

....well-known capacitor shortcomings such as dielectric absorption and series resistance, and perhaps the vulnerability of the dielectric film in electrolytics to reverse-biasing. No-one has yet shown how these imperfections could cause capacitor audibility in properly designed equipment.

The last sentence is a key one - "in properly designed equipment".

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.