What Exactly Does "Burn In" do for Electronics?

It makes no sense that the expectation is for parts to fall out of spec in order to fall into a desired lower cumulative level of performance. Ridiculous. And how would this be accomplished within a reasonable time frame? By using inferior quality parts? Again, ridiculous.

06-22-14: Csontos
It makes no sense that the expectation is for parts to fall out of spec in order to fall into a desired lower cumulative level of performance. Ridiculous. And how would this be accomplished within a reasonable time frame? By using inferior quality parts? Again, ridiculous.

Exactly, when a unit is tested and adjusted up before it leaves the factory, it should stay this way for some time, for years we all hope.
To say that components change their characteristics after this because of "burn in" hours, means those adjustments will out out of spec, after the burn in.

Brand new capacitors do what's called "form" but this only takes minutes and they should already be "formed" by the time it takes to do the final spec adjustments in the factory before shipping.

The only thing in audio I know of that degrades relatively quickly from the first time it's switched on is tubes. And if they don't have auto bias circuits to keep them in spec, they need to be measured and adjusted every now and again. As they do loose the bias adjustment, depending on how many hours they are on.

Cheers George

A stupid attempt at lending credence to the notion that wires and cables have a wacky ability to magically alter performance.

Interconnects can sometimes alter things, all are different in construction, and parameters such as impedance, capacitance and inductance, of the cable can have filtering effects when used on high output impedance devices, such tube preamps and passive volume controls.
But anyone who says they need "burning in" with burn in gadgets and burn in cd's needs to be taken with a grain of salt.

Cheers George

It makes no sense that the expectation is for parts to fall out of spec in order to....

That was never said or implied. All that was is that things don't stay new. Tubes aren't the only things that age due to heating up. Anything electricity encounters the slows down it's travel heats it up. So cold, out of the box won't and can't sound the same as when on for awhile.

A really stupid attempt...

Really? Is this baggage from some older thread?

Nothing I know of sounds best, functions best, drives best, or operates best until broken in. Please name one thing that does.Then there is a long period of great performance. To say that it only doesn't apply to electronics is goofy, to be polite.

The signal doesn't magically travel through cables, capacitors, tubes, traces and the like and not leave a trace or have an affect. That affect is the lessening of the time it takes to sound it's best.

All the best,
Nonoise