Why don't higher end amplifiers come with a separate power chassis?

@antigrunge2 

Well now we seem to be locked into the PC debate.

No.  if the manufacturers thought their customers were going to buy their own PCs they would not include a PC at all, thus saving the buyers the cost of any supplied PC.  Nor in any amplifier handbook that I have seen has it been suggested by the manufacturer than replacing the power cord might have an advantageous effect on SQ.  Surely if the manufacturer believed it could, they would make such suggestion.  Its absence and the absence of a costly PC should answer the question.

Manufacturers want to sell amplifiers.  So at shows they probably choose to indulge their potential customers who think PCs make a difference, not wishing to get into pointless negative arguments with people who know less about the subject than they do.

There are some amp manufacturers who do think aftermarket power cords make a difference in sound quality.

Yes, The  AGD Audions come with quality power cords.

There are some amp manufacturers who do think aftermarket power cords make a difference in sound quality.

I do not doubt that for a moment. One thing is certain, confirmational bias is powerful. If someone is convince something will not make a difference, it certainly will not. This mindset can be extraordinarily rigid and unreceptive. Debate will be pointless.

Charles

@pwayland - The effectiveness of a tiny bit of resistance in the power supply to reduce or eliminate noise should not be underestimated.  DC sources with a tiny resistor in the way are going to perform much better in terms of noise rejection.

This is why it drives me a little nuts to see audiophiles trying to use car battery cables all the way to the transformers. The resistance and inductance between you and the rest of the world is a plus.