Why manufactures don´t burn in their amps and ...

Because they simply tend to 'UNBURN-IN'and that is logical..Next time find out for yourself when you buy a pair of new amps!! Run a varied signal through one of
them for 48 hours-no more needed. Then listen to it in
mono-carefully. Do not rush. Then listen to the unplayed one for comparison-in mono. Now unhook the first one and
place it in another room for 2 weeks. It will not sound
as good as it did before and not as good as the second
one you had been playing for 2 weeks. It is changed=
UN-Burned-in!

I'll change my stock powercords when audio engineers such as LFD's Dr.Bews and design engineers at Benchmark Media supply/sell ones they stand behind as providing sonic improvements with their products. Another words, very likely they'll be no powercord changes in my future (o:

You won't be hurting anyone but yourself, in having ripped yourself off for the musical rewards. Even the better recording studios have discovered the audible benefits of upgrading power cords/cables in the recording/mastering chain. I suppose that's just their imagination too?

For those who wonder how a power cord can make a difference, consider this: an amplifier has a power transformer, rectifiers and filter capacitors in its power supply. Normally, the filter caps are charged by the rectifiers as the transformer makes voltage.

When the filter caps are nearly charged, the only time that the rectifiers will conduct is at the peaks of the 60Hz input waveform. So all the energy going into the amp is concentrated at the peaks. This is the point that the diodes turn on, as the voltage on them is higher than the voltage on the filter caps.

As soon as the wave is past peak, the rectifiers will turn off, when the filter cap voltage is higher than the voltage from the rectifiers.

So the energy going into the amp is often doing **only at the peaks**. The difference between a cheap power cord and an expensive one, in terms of its ability to dump large amounts of current during these peaks is only about 3%. It is that 3% that audiophiles hear.

A second phenomena is AC voltage drop across the cord. We have measured nearly 3 volts in some cases. In a 100-watt amplifier that can account for a nearly 50% DROP in power!!!

If you think these two phenomena are not audible you're missing a bet. The bigger the amp (IOW the more power drawn), the more audible power cords become.

We figured some of this stuff out nearly 20 years ago, which is why one of our bigger amps (the MA-2) actually runs two power cords per chassis (since there are 2 AC circuits in the amp for 2 power transformers) to limit the audible effects of the power cords. Back then there were not nearly so many exotic cords as there are now! -so we had to make do and adding a power cord worked out very nicely.

Ralph;are there any cords that work better with your amps
that you like as a preference;you already gave me great advice on the Mogami balanced cables so I thought I would ask on the cords.