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

I listened to my system for a year with the stock power cord.
I decided to try a new cord and it did make a difference.
A window in my room began vibrating/rattling.
Never did before.
Some frequency was boosted and made that glass vibrate.

We do 90% of the burn-in here in our shop. The last 10% takes the longest time- up to 6-8 weeks depending on the number of hours a day. Especially when you have amps or preamps built up with custom options, doing an extended burn-in is just plain impractical!

As to power cords, we acknowledge that power cords are going to make a difference. That is why we install IEC connectors on our products. The problem is, what we think is the best power cord may not be what you think is the best power cord. In fact we have seen a power cord work great in one installation and make no difference in another. You have to take into account that variables of house wiring, cleanliness of the AC power, neighborhood line voltage and other system anomalies that will affect what the end user thinks is the 'best'.

Guess what? No-one can do predict all that- so that is why we supply our gear with IEC connectors. Our stuff is known for being really transparent- and we invite you to experiment. That is the only way I know of to sort out what is going to work in the area of power cords. It would be frustrating as an end user to realize that a $200 power cord had been included with the unit, only to find out that in your system its not the right combination!

i am not aware of any manufucturerer who will assert that cables which interface a component have no affect upon the sound of that component. most manufacturers willtell you to burn in the component before criticial listening.

regarding double blind tests to assess burn in, i would like to read the protocols of such experiments so i can judge for myself.

this hobby is so subjective that when you have 2 audiophiles in a room, you will get three opinions.

Insist on buying the demo unit from the dealer, if it is in adequate cosmetic condition to you ! With full warranty starting the day you pick it up ( which is usually the case ). Let him break-in the next one !